Removable storage device

Abstract

When the consumption current level supported by the removable storage device is an other consumption current level than the first consumption current level, which is the consumption current level having the largest consumption current value, among the plurality of consumption current levels, the first consumption current value consumed by the removable storage device from the first power source is below the third allowable current value associated with the first power source specified by the other consumption current level, and the second consumption current value consumed by the removable storage device from the second power source is below the fourth allowable current value associated with the second power source specified by the other consumption current level.

Description

Technical Field

[0001] Embodiments of the present invention relate to a portable storage device that operates using multiple power supplies supplied from a host computer. Background Technology

[0002] In recent years, the industry has developed small, high-speed, and high-capacity portable storage devices.

[0003] As such portable storage devices, portable storage devices that operate using multiple power supplies with different voltages are known.

[0004] In the standardization of such multi-power-source removable storage devices, new technologies are sought to enable the design of host-side power supply structures required for the operation of removable storage devices.

[0005] [Background Technical Documents]

[0006] [Patent Literature]

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-173765 Summary of the Invention

[0008] [The problem the invention aims to solve]

[0009] One embodiment of the present invention aims to provide a portable storage device that allows for easy design of the host-side power supply structure.

[0010] [Technical means to solve the problem]

[0011] According to one embodiment, the removable storage device can be inserted into and removed from a socket within a host computer and operates via first and second power supplies supplied from the host computer. The first and second power supplies have different voltages. The removable storage device includes multiple terminals, non-volatile memory, and a controller for controlling the non-volatile memory. These terminals include one or more first power supply terminals supplied with the first power supply and one or more second power supply terminals supplied with the second power supply. The removable storage device is configured to support one of multiple current consumption levels, each specifying a different current consumption level. Among the multiple current consumption levels, both the current consumption associated with the first power supply and the current consumption associated with the second power supply are specified. When the current consumption level supported by the removable storage device is the first current consumption level with the largest current consumption value among the multiple current consumption levels, the first current consumption value consumed by the removable storage device from the first power source is less than or equal to the maximum current value (i.e., the first permissible current value) that can be supplied from the host to the more than one first power source terminal of the removable storage device via the contact resistance value between the terminal of the socket and the terminal of the removable storage device. Similarly, the second current consumption value consumed by the removable storage device from the second power source is less than or equal to the maximum current value (i.e., the second permissible current value) that can be supplied from the host to the more than one second power source terminal of the removable storage device via the contact resistance value. When the current consumption level supported by the removable storage device is another current consumption level different from the first current consumption level, the first current consumption value is less than or equal to the third permissible current value (i.e., the third permissible current value) related to the first power source as defined by the other current consumption level, and the second current consumption value is less than or equal to the fourth permissible current value (i.e., the fourth permissible current value) related to the second power source as defined by the other current consumption level. Attached Figure Description

[0012] Figure 1A This is a top view of the first side of the removable storage device according to the embodiment.

[0013] Figure 1B This is a side view of the removable storage device according to the embodiment.

[0014] Figure 1C This is a top view of the second side of the removable storage device according to the embodiment.

[0015] Figure 2 This is a diagram illustrating a structural example of a removable storage device according to an embodiment.

[0016] Figure 3 This is a top view showing the external shape of the removable storage device and an example of the configuration of multiple terminals according to an embodiment.

[0017] Figure 4 This is a top view showing the external shape of the socket into which the removable storage device is inserted, and an example of the arrangement of multiple lead terminals.

[0018] Figure 5 This is a side view showing the state of the removable storage device inserted into the socket according to the embodiment.

[0019] Figure 6 This is a diagram illustrating an example of the configuration of multiple power terminals of a removable storage device that operates using two power supplies.

[0020] Figure 7 This is a block diagram illustrating an example of the power supply structure of a portable storage device that utilizes two power supplies for operation.

[0021] Figure 8 This is a block diagram illustrating another example of the power supply structure of a portable storage device that utilizes two power supplies for operation.

[0022] Figure 9 This is a diagram illustrating an example of the configuration of multiple power terminals of a portable storage device that utilizes a three-power-operated implementation.

[0023] Figure 10 This is a block diagram illustrating an example of the power supply structure of a portable storage device that utilizes a 3-power-operated method.

[0024] Figure 11 This is a block diagram illustrating another example of the power supply structure of a portable storage device that utilizes a three-power supply operation.

[0025] Figure 12 This diagram illustrates four examples of power supply structures applicable to removable storage devices in various implementation methods.

[0026] Figure 13 It is a diagram representing various current consumption levels.

[0027] Figure 14 It is a graph showing the calculation formula for the current consumption specified for each power source according to each current consumption level and the allowable current reduction rate.

[0028] Figure 15 This is a diagram showing an example of the formula for calculating the current consumption of each power source according to each current consumption level, and an example of the allowable current reduction rate.

[0029] Figure 16 It is a graph showing the allowable current value of the first power source calculated based on the contact resistance value, the power supply variation rate of the first power source, and the lower limit voltage of the first power source.

[0030] Figure 17It is a graph showing the allowable current value of the second power source, calculated based on the contact resistance value, the power supply variation rate of the second power source, and the lower limit voltage of the second power source.

[0031] Figure 18 This is a graph showing the allowable current ratio for CC1max and the allowable current of each power supply for the four current levels CC1 to CC4.

[0032] Figure 19A It is a diagram showing the current consumption level guidelines for each of the various current consumption levels, indicating the permissible current value of each power source and the current consumption level guidelines for device performance.

[0033] Figure 19B This is a diagram showing the current rating and current rating guidelines (1) for IP1 = IP2 and -1% variation.

[0034] Figure 19C This is a diagram showing the current rating and current rating guidelines (2) for IP1 = IP2 and -2% variation.

[0035] Figure 19D This is a diagram showing the current rating and current rating guidelines (1') for cases where IP1 ≠ IP2 and -1% variation.

[0036] Figure 19E This is a diagram showing the current rating and current rating guidelines (2') for cases where IP1 ≠ IP2 and -2% variation.

[0037] Figure 20 This is a diagram showing the markings and two-dimensional barcodes on one surface of the package of the removable storage device in the embodiment, and the markings and two-dimensional barcodes on the casing of the host device.

[0038] Figure 21 It is a flowchart showing the sequence of device initialization processes executed in the host.

[0039] Figure 22 This is a diagram showing a notch formed in the package of the removable storage device in the embodiment for identifying the current consumption level supported by the removable storage device.

[0040] Figure 23 This is a diagram showing examples of the power supply structure on the host side corresponding to the four current consumption levels.

[0041] Figure 24 This is a diagram showing the heat dissipation path of the device.

[0042] Figure 25 This is a diagram illustrating an example of a heat dissipation mechanism on the host side corresponding to a power supply structure with a high current consumption level.

[0043] Figure 26 This is a diagram illustrating an example of a heat dissipation mechanism on the host side, corresponding to a power supply structure with a low current consumption level. Detailed Implementation

[0044] The following describes the implementation method with reference to the drawings.

[0045] First, refer to Figure 1A , Figure 1B ,as well as Figure 1C The external shape of the removable storage device 10 in the embodiment will be described. Figure 1A This is a top view showing one surface of the removable storage device 10. Figure 1B This is a side view showing the side of the removable storage device 10. Figure 1C This is a top view showing another surface of the removable storage device 10.

[0046] In this specification, the X-axis, Y-axis, and Z-axis are defined. The X-axis, Y-axis, and Z-axis are orthogonal to each other. The X-axis is along the width of the removable storage device 10. The Y-axis is along the length (height) of the removable storage device 10. The Z-axis is along the thickness of the removable storage device 10.

[0047] The removable storage device 10 is a storage device that can be inserted into and removed from a socket within a host computer (host device). The removable storage device 10 is configured to operate via multiple power supplies supplied from the host computer. These multiple power supplies have different voltages. The power supplies supplied from the host computer to the removable storage device 10, or the power wiring used to supply the multiple power supplies from the host computer to the removable storage device 10, are referred to as power rails.

[0048] For example, in the case where the removable storage device 10 is implemented as a storage device having a power structure that operates using two types of power supplies supplied from the host, a first power supply with a first voltage is supplied to the removable storage device 10 via a first power rail from a first power management IC in the host, and a second power supply with a second voltage is supplied to the removable storage device 10 via a second power rail from a second power management IC in the host.

[0049] like Figure 1A As shown, the removable storage device 10 includes a thin, plate-like package (body) 11. The body 11 of the removable storage device 10 is formed, for example, as a generally rectangular plate extending along the Y-axis direction. The Y-axis direction is the direction of the long side of the body 11 of the removable storage device 10.

[0050] The main body 11 is plate-shaped and has a first surface 21, a second surface 22, and an outer edge 23. The first surface 21 and the second surface 22 are formed into a roughly quadrilateral (rectangular) shape extending along the Y-axis direction. That is, the Y-axis direction is also the direction of the long side of the first surface 21 and the second surface 22.

[0051] Surface 1 21 is a generally flat surface facing the positive direction of the Z-axis. Surface 22 is located on the opposite side of surface 1 21 and is a generally flat surface facing the negative direction of the Z-axis.

[0052] The outer edge 23 is disposed between the first surface 21 and the second surface 22, connecting the edge portion of the first surface 21 and the edge portion of the second surface 22. The outer edge 23 has: a first edge 31, a second edge 32, a third edge 33, a fourth edge 34, a first corner portion 35, a second corner portion 36, a third corner portion 37, and a fourth corner portion 38.

[0053] The first edge 31 extends along the X-axis direction and towards the positive Y-axis direction. The X-axis direction is the direction of the short sides of the main body 11, the first surface 21, and the second surface 22, and includes both the positive and negative X-axis directions.

[0054] The second edge 32 extends along the Y-axis and towards the negative X-axis. The third edge 33 is located on the opposite side of the second edge 32, extends along the Y-axis, and towards the positive X-axis. The fourth edge 34 is located on the opposite side of the first edge 31, extends along the X-axis, and towards the negative Y-axis.

[0055] The lengths of the second edge 32 and the third edge 33 are longer than the lengths of the first edge 31 and the fourth edge 34. The first edge 31 and the fourth edge 34 form the short side of the generally rectangular storage device 10, and the second edge 32 and the third edge 33 form the long side (side) of the generally rectangular movable storage device 10.

[0056] The first corner 35 is the corner portion between the first edge 31 and the second edge 32, connecting the end of the first edge 31 in the negative direction of the X-axis and the end of the second edge 32 in the positive direction of the Y-axis.

[0057] The first corner portion 35 extends in a straight line between the negative X-axis end of the first edge 31 and the positive Y-axis end of the second edge 32. The first corner portion 35 is formed by setting the angle between the first edge 31 and the second edge 32 as a chamfer called C1.1 (also known as a C-chamfer). According to another expression, the first corner portion 35 is a chamfered portion C formed between the first edge 31 and the second edge 32.

[0058] The second corner portion 36 is the corner portion between the first edge 31 and the third edge 33, connecting the end of the first edge 31 in the positive X-axis direction and the end of the third edge 33 in the positive Y-axis direction. The second corner portion 36 extends in an arc shape between the end of the first edge 31 in the positive X-axis direction and the end of the third edge 33 in the positive Y-axis direction. The second corner portion 36 is provided by setting the angle between the first edge 31 and the third edge 33 as a rounded chamfer of R0.2 (also called an R-chamfer). In this way, the corner shape of the first corner portion 35 and the shape of the second corner portion 36 are different.

[0059] The third corner portion 37 connects the negative Y-axis end of the second edge 32 to the negative X-axis end of the fourth edge 34. The fourth corner portion 38 connects the negative Y-axis end of the third edge 33 to the positive X-axis end of the fourth edge 34. The third corner portion 37 and the fourth corner portion 38 extend in an arc shape, similar to the second corner portion 36.

[0060] The lengths of the main body 11, the first surface 21, and the second surface 22 in the Y-axis direction are set to approximately 18 ± 0.10 mm, and the lengths in the X-axis direction are set to approximately 14 ± 0.10 mm. That is, the distance between the first edge 31 and the fourth edge 34 in the Y-axis direction is set to approximately 18 ± 0.1 mm, and the distance between the second edge 32 and the third edge 33 in the X-axis direction is set to approximately 14 ± 0.10 mm. However, the lengths of the main body 11, the first surface 21, and the second surface 22 in the X-axis and Y-axis directions are not limited to this example.

[0061] The thickness of the main body 11 and the outer edge 23 in the Z-axis direction is set to approximately 1.4 mm ± 0.10 mm. That is, the distance between the first surface 21 and the second surface 22 in the Z-axis direction is set to approximately 1.4 mm ± 0.10 mm. In addition, the length of the outer edge 23 in the Z-axis direction is not limited to this example.

[0062] like Figure 1B As shown, the main body 11 further has an inclined portion 39. The inclined portion 39 is the corner portion between the first surface 21 and the first edge 31, and extends in a straight line between the end of the first surface 21 in the positive direction of the Y axis and the end of the first edge 31 in the positive direction of the Z axis.

[0063] like Figure 1A As shown, a plurality of terminals are arranged on the first surface 21 of the removable storage device 10. Each of these terminals is also referred to as an external connection terminal. Figure 1A In the diagram, multiple terminals are represented by small rectangles.

[0064] Multiple terminals are configured, for example, as three columns: column 1 (R1), column 2 (R2), and column 3 (R3). The terminal group configured in column 1 (R1) is referred to as the first column terminal group. The first column terminal group includes, for example, multiple signal terminals for transmitting and receiving differential signals for two channels as specified in the PCI Express (registered trademark) (PCIe) specification. The signal terminals corresponding to one channel include two terminals assigned to receive differential signal pairs and two terminals assigned to transmit differential signal pairs. The two terminals assigned to receive differential signal pairs and the two terminals assigned to transmit differential signal pairs are adjacent to each other across a ground terminal, which is located between the two terminals assigned to receive differential signal pairs and the two terminals assigned to transmit differential signal pairs. That is, any two terminals of an assigned differential signal pair are surrounded by two ground terminals located on either side of those two terminals.

[0065] The terminal group in column R2 is referred to as the second terminal group. The second terminal group may include, for example, several signal terminals for optional signals. Additionally, the second terminal group may include an additional power terminal for use with a 3-power supply configuration.

[0066] The terminal group of column 3 R3 is referred to as the 3rd column terminal group. The 3rd column terminal group includes: several signal terminals assigned to sideband signals specified by the PCIe specification (e.g., reset signal PERST#, clock request signal CLKREQ#, reference clock pair CLKREF), one or more first power supply terminals supplied with a first power supply having a first voltage, one or more second power supply terminals supplied with a second power supply having a second voltage different from the first voltage, and several ground terminals.

[0067] Figure 2 This shows a structural example of the removable storage device 10.

[0068] like Figure 2 As shown, a substrate 12, a NAND flash memory 13, and a controller 14 for controlling the NAND flash memory 13 are disposed inside the main body 11 of the removable storage device 10. The NAND flash memory 13 and the controller 14 are mounted on the surface of the substrate 12. The NAND flash memory 13 comprises a plurality of NAND flash memory dies stacked on the surface of the substrate 12.

[0069] The back side of substrate 12, opposite to the surface of substrate 12, is exposed and functions as the first surface 21. A [structure / feature] is disposed on the back side of substrate 12. Figure 1A The multiple terminals described.

[0070] The NAND flash memory 13 and the controller 14 are covered and sealed by a molding resin 40 formed in a manner that forms the main body (main body 11) of the removable storage device 10.

[0071] Figure 3 This is a top view showing the external shape of the removable storage device 10 and an example of the configuration of multiple terminals.

[0072] like Figure 3 As shown, the removable storage device 10 has multiple terminals P. Terminals P are sometimes also referred to as pads. Figure 3 In this example, the removable storage device 10 is shown to have 32 terminals P, but the number of terminals P is only one example and is not limited to this example. That is, the number of terminals P may be less than 32 or more than 32. Multiple terminals P are disposed on the back side of the substrate 12 and exposed on the first surface 21. No terminals P are provided on the second surface 22. The second surface 22 may be used, for example, as a marking area.

[0073] like Figure 3 As shown, the first column of terminals arranged in the first column R1 includes 13 terminals P101 to P113 arranged at intervals in the X-axis direction, closer to the first edge 31 than the fourth edge 34. Terminals P101 to P113 are arranged in the X-axis direction along the first edge 31 near the first edge 31.

[0074] The second terminal group located in the second column R2 includes six terminals P114 to P119 arranged at intervals along the X-axis, closer to the fourth edge 34 than the first edge 31. Terminals P114 to P116 are arranged along the fourth edge 34 in the X-axis direction, closer to the second edge 32 than the third edge 33. Terminals P117 to P119 are arranged along the fourth edge 34 in the X-axis direction, closer to the third edge 33 than the second edge 32. According to another expression, terminals P114 to P116 are positioned between the center line (indicated by a dashed line) of the removable storage device 10 and the main body 11 in the X-axis direction and the second edge 32, and terminals P117 to P119 are positioned between the center line of the removable storage device 10 and the main body 11 in the X-axis direction and the third edge 33. The gap between terminals P116 and P117, which belong to the second terminal group, is wider than the gap between other adjacent terminals in the X-axis direction (specifically, the gap between terminals P114 and P115, the gap between terminals P115 and P116, the gap between terminals P117 and P118, and the gap between terminals P118 and P119).

[0075] The third column of terminals in column R3 comprises 13 terminals P120 to P132 arranged at intervals along the X-axis, closer to the fourth edge 34 than the first edge 31. Terminals P120 to P132 in column R3 are arranged closer to the fourth edge 34 than terminals P114 to P119 in column R2.

[0076] Figure 4 This is a top view showing the external shape of the socket 100 into which the removable storage device 10 is inserted and an example of the configuration of multiple lead terminals.

[0077] In the socket 100, multiple lead terminals 104 are arranged in three columns r1, r2, and r3, respectively, corresponding to the first, second, and third column terminal groups of the removable storage device 10. These lead terminals are sometimes referred to as spring leads. The removable storage device 10 is arranged with its first surface 21 facing the socket 100, accommodating the multiple lead terminals 104. Figure 4 On socket 100.

[0078] There are 13 lead terminals 104 in the first column r1. Similarly, there are 6 lead terminals 104 in the second column r2 and 13 lead terminals 104 in the third column r3.

[0079] Each lead terminal 104 includes a contact portion 105 that contacts a corresponding terminal of the removable storage device 10. Each lead terminal 104 is adhered to the frame 106 of the socket 100.

[0080] The frame 106 of the socket 100 has: a first edge 111, a second edge 112, a third edge 113, a fourth edge 114, and a connecting portion 115. The first edge 111, the second edge 112, the third edge 113, and the fourth edge 114 correspond to the top, bottom, left, and right sides of the rectangular frame 106. The connecting portion 115 connects the middle portion of the second edge 112 and the middle portion of the third edge 113.

[0081] The 13 lead terminals 104 of the first column r1 are bonded to the first edge 111 of the frame 106. The 6 lead terminals 104 of the second column r2 are bonded to the connecting part 115 of the frame 106. The 13 lead terminals 104 of the third column r3 are bonded to the fourth edge 114 of the frame 106.

[0082] Figure 5 This is a side view showing the state in which the removable storage device 10 is inserted into the socket 100.

[0083] As for the type of socket 100, various types such as double push, push pull, and hinged can be used, but here, a hinged socket 100 will be used as an example for explanation.

[0084] The cover 120 is mounted on the frame 106 in a manner that it rotates around the pivot 121, which functions as a hinge. With the cover 120 in the open position, the movable storage device 10 is inserted into the cover 120. Then, when the cover 120 is closed, as... Figure 5As shown, each terminal P disposed on the first surface 21 of the removable storage device 10 contacts the contact portion 105 of the corresponding lead terminal 104 in the socket 100. Thus, each terminal P disposed on the first surface 21 of the removable storage device 10 is electrically connected to the wiring on the printed circuit board substrate inside the host.

[0085] In this way, the removable storage device 10 is electrically connected to the printed circuit board substrate within the host via the socket 100. Therefore, compared to embedded storage devices such as ball grid array (BGA) type storage devices where each terminal is directly soldered to the printed circuit board substrate within the host, the number of terminals that can be configured in the removable storage device 10 is reduced. Due to this limitation on the number of terminals, the number of power terminals for each power supply is also limited. Therefore, in the removable storage device 10, there is a tendency for the current supplied to a single power terminal to become larger.

[0086] Furthermore, a contact resistance exists between each terminal P of the removable storage device 10 and each lead terminal 104 (contact portion 105) of the socket 100. Since the terminals P and lead terminals 104 are not bonded together by soldering, the contact resistance between terminals P and lead terminals 104 is relatively large. The voltage drop caused by this contact resistance reduces the voltage supplied from the host to each power terminal of the removable storage device 10. The contact resistance between terminals P and lead terminals 104 is also used as a reference for the contact resistance value of the device socket.

[0087] Therefore, due to the voltage drop caused by the contact resistance, the voltage supplied to each power terminal of the removable storage device 10 decreases, and the tolerance between the voltage supplied to each power terminal and the lower limit voltage of each power supply required for the operation of the removable storage device 10 tends to become smaller.

[0088] Next, an example of the power supply structure of the removable storage device 10 will be described.

[0089] First, the portable storage device 10 with a two-power-supply structure, that is, the portable storage device 10 that operates using two power supplies, will be described.

[0090] Figure 6 This diagram illustrates an example configuration of multiple power terminals of a removable storage device 10 operating on two power supplies. Figure 6 The example illustrates a case where the number of power terminals supplied with the first power source is 3 and the number of power terminals supplied with the second power source is 3. However, the number of power terminals supplied with the first power source and the number of power terminals supplied with the second power source are not limited to this example. The number of power terminals supplied with the first power source is 1 or more, and the number of power terminals supplied with the second power source is also 1 or more.

[0091] The first power supply (i.e., power rail PWR_1) has a voltage of, for example, 3.3V or 2.5V. The following mainly describes the case where the first power supply (PWR_1) has 2.5V. 2.5V is the nominal value of the voltage of the first power supply (PWR_1); in reality, the first power supply (PWR_1) has a voltage range corresponding to a certain power supply fluctuation rate.

[0092] The first power supply (PWR_1) is supplied, for example, to three terminals contained in the third column of terminals, namely terminals P128, P130, and P131. Terminals P128, P130, and P131 function as power supply terminals for the first power supply (PWR_1).

[0093] The second power source (i.e., power rail PWR_2) has, for example, a voltage of 1.2V. 1.2V is the nominal value of the voltage of the second power source (PWR_2). In reality, the second power source (PWR_2) has a voltage range corresponding to a certain power source variation rate.

[0094] The second power supply (PWR_2) is supplied, for example, to three terminals contained in the third column of terminals, namely terminals P124, P125, and P127. Terminals P124, P125, and P127 function as power terminals for the second power supply (PWR_2).

[0095] Figure 7 This is a block diagram illustrating an example of the power supply structure of a removable storage device 10 that operates using two power supplies.

[0096] The NAND flash memory 13 included in the removable storage device 10 includes a NAND interface circuit 131 and a memory cell array 132 referred to as a NAND cell array.

[0097] The NAND interface circuit 131 performs the following actions: receiving command sequences (read command sequences, write command sequences, erase command sequences, etc.) and data from the controller 14; writing data to the NAND cell array based on the received write command sequence; reading data from the NAND cell array based on the received read command sequence; erasing data in block units based on the received erase command sequence; and sending status and read data to the controller 14.

[0098] The storage cell array 132 contains multiple blocks. Each block contains multiple pages. Each block is the unit for data erase operations. Each page is the unit for data write operations and data read operations.

[0099] The first power supply (PWR_1) with a voltage of 2.5V is mainly used as the power supply for operating the memory cell array 132. The second power supply (PWR_2) with a voltage of 1.2V is mainly used as the power supply for operating the NAND interface circuit 131.

[0100] The controller 14 includes: a physical layer (PHY-A) 141 containing analog circuitry, core logic 142, and NAND interface circuitry 143.

[0101] The physical layer (PHY-A) 141 communicates with the host via a PCIe serial bus. More specifically, the physical layer (PHY-A) 141 uses multiple channels (e.g., 2 channels) of PCIe signals (2 pairs of differential signals per channel) to communicate with the host, and transmits and receives several PCIe sideband signals between itself and the host.

[0102] The core logic 142 contains various logics for performing internal actions of the controller 14. This core logic 142 performs, for example, the processing of interpreting and executing commands from the host, and ECC (Error Correction Code) encoding / decoding.

[0103] NAND interface circuit 143 is an interface circuit that performs communication with NAND flash memory 13. NAND interface circuit 143 performs the following actions: sending command sequences (read command sequences, write command sequences, erase command sequences, etc.) and data to NAND flash memory 13, and receiving status and reading data from NAND flash memory 13.

[0104] exist Figure 7 In the power supply structure (Example-1), the first power supply (PWR_1) with 2.5V is further used to generate internal power supplies for operating the physical layer (PHY-A) 141 and for operating the core logic 142.

[0105] Here, a DC / DC converter or a buck converter such as an LDO (Low Drop Output) regulator is used. In the following description, the term DC / DC converter is used representatively.

[0106] More specifically, a first power supply of 2.5V (PWR_1) is supplied to both DC / DC converter 151 and DC / DC converter 152. DC / DC converter 151 converts the first power supply of 2.5V (PWR_1) to a specific voltage lower than 2.5V (e.g., 1.8V), and supplies this converted specific voltage to the physical layer (PHY-A) 141 as an internal power supply for operating the physical layer (PHY-A) 141. DC / DC converter 152 converts the first power supply of 2.5V (PWR_1) to another specific voltage lower than 2.5V (e.g., 0.8V), and supplies this converted specific voltage to the core logic 142 as an internal power supply for operating the core logic 142.

[0107] The current consumed from the first power supply (PWR_1) in the removable storage device 10 is the sum of the current consumed by the memory cell array 132, the core logic 142, and the physical layer (PHY-A) 141. Therefore, the current consumed from the first power supply (PWR_1) in the removable storage device 10 depends on the structure of each of the memory cell array 132, the core logic 142, and the physical layer (PHY-A) 141, as well as the performance of the removable storage device 10.

[0108] The current consumed from the second power supply (PWR_2) in the removable storage device 10 is the sum of the current consumed by the NAND interface circuit 131 in the NAND flash memory 13 and the current consumed by the NAND interface circuit 143 in the controller 14. Therefore, the current consumed from the second power supply (PWR_2) in the removable storage device 10 depends on the structure of each of these NAND interface circuits 131 and 143, as well as the performance of the removable storage device 10.

[0109] Figure 8 This is a block diagram illustrating another example of a power supply structure for a removable storage device 10 that operates using two power supplies.

[0110] exist Figure 8 In the power supply structure (Example-2), the internal power supply used to operate the core logic 142 is generated from a second power supply (PWR_2) with 1.2V, instead of the first power supply (PWR_1) with 2.5V. Other aspects are similar to... Figure 7 The power supply structure is the same as that in Example-1.

[0111] A second power supply (PWR_2) with a voltage of 1.2V is supplied to the DC / DC converter 201. The DC / DC converter 201 converts the second power supply (PWR_2) with a voltage lower than 1.2V (e.g., 0.8V) and supplies the converted voltage to the core logic 142 as an internal power supply for operating the core logic 142.

[0112] The current consumed from the first power supply (PWR_1) in the removable storage device 10 is the sum of the current consumed by the storage cell array 132 and the current consumed by the physical layer (PHY-A) 141. Therefore, the current consumed from the first power supply (PWR_1) in the removable storage device 10 depends on the structure of each of the storage cell array 132 and the physical layer (PHY-A) 141, as well as the performance of the removable storage device 10.

[0113] The current consumed from the second power supply (PWR_2) in the removable storage device 10 is the sum of the current consumed by the NAND interface circuit 131 in the NAND flash memory 13, the current consumed by the NAND interface circuit 143 in the controller 14, and the current consumed by the core logic 142. Therefore, the current consumed from the second power supply (PWR_2) in the removable storage device 10 depends on the structure of each of these NAND interface circuits 131, 143 and core logic 142, as well as the performance of the removable storage device 10.

[0114] Next, the portable storage device 10 with a 3-power supply structure, that is, the portable storage device 10 that operates using 3 power supplies, will be described.

[0115] Figure 9 This diagram illustrates an example configuration of multiple power terminals of a removable storage device 10 operating on three power supplies. Figure 9 The example illustrates a case where the number of power terminals supplied with the first power source is 3, the number of power terminals supplied with the second power source is 3, and the number of power terminals supplied with the third power source is 1. However, the number of power terminals supplied with the first power source, the second power source, and the third power source is not limited to this example. The number of power terminals supplied with the first power source, the second power source, and the third power source can all be 1 or more.

[0116] The first power supply (PWR_1) with 2.5V is supplied to the three terminals in the third terminal group, namely terminals P128, P130, and P131, in the same manner as in the case of the second power supply configuration. The second power supply (i.e., power rail PWR_2) with 1.2V is also supplied to the three terminals in the third terminal group, namely terminals P124, P125, and P127, in the same manner as in the case of the second power supply configuration.

[0117] The third power supply (i.e., power rail PWR_3) has, for example, a voltage of 1.8V. 1.8V is the nominal value of the voltage of the third power supply (PWR_3). In reality, the third power supply (PWR_3) has a voltage range corresponding to a certain power supply variability.

[0118] A third power supply (PWR_3) with 1.8V is supplied, for example, to one terminal, namely terminal P117, contained in the second column of terminal groups.

[0119] Figure 10 This is a block diagram illustrating an example of the power supply structure of a removable storage device 10 that operates using three power supplies.

[0120] exist Figure 10 In the power supply structure (Example-3), with Figure 7 The power supply structure (Example-1) is different in that only the 1.8V third power supply (PWR_3) is used as the internal power supply for operating the physical layer (PHY-A) 141.

[0121] The current consumed from the first power supply (PWR_1) in the removable storage device 10 is the sum of the current consumed by the memory cell array 132 and the current consumed by the core logic 142. Therefore, the current consumed from the first power supply (PWR_1) in the removable storage device 10 depends on the structure of each of the memory cell array 132 and the physical layer (PHY-A) 141, as well as the performance of the removable storage device 10.

[0122] The current consumed from the second power supply (PWR_2) in the removable storage device 10 is the sum of the current consumed by the NAND interface circuit 131 in the NAND flash memory 13 and the current consumed by the NAND interface circuit 143 in the controller 14. Therefore, the current consumed from the second power supply (PWR_2) in the removable storage device 10 depends on the structure of each of these NAND interface circuits 131 and 143, as well as the performance of the removable storage device 10.

[0123] The current consumption value from the third power supply (PWR_3) in the removable storage device 10 is the current consumption value of the physical layer (PHY-A) 141. The current consumption value from the third power supply (PWR_3) in the removable storage device 10 depends on the structure of the physical layer (PHY-A) 141 and the performance of the removable storage device 10.

[0124] Figure 11 This is a block diagram illustrating another example of a power supply structure for a removable storage device 10 that operates using three power supplies.

[0125] exist Figure 11 In the power supply structure (Example-4), with Figure 8 The power supply structure (Example-2) is different in that only the 1.8V third power supply (PWR_3) is used as the internal power supply for operating the physical layer (PHY-A) 141.

[0126] The current consumption value consumed from the first power supply (PWR_1) in the removable storage device 10 is the current consumption value of the storage cell array 132. Therefore, the current consumption value consumed from the first power supply (PWR_1) in the removable storage device 10 depends on the structure of the storage cell array 132 and the performance of the removable storage device 10.

[0127] The current consumed from the second power supply (PWR_2) in the removable storage device 10 is the sum of the current consumed by the NAND interface circuit 131 in the NAND flash memory 13, the current consumed by the NAND interface circuit 143 in the controller 14, and the current consumed by the core logic 142. Therefore, the current consumed from the second power supply (PWR_2) in the removable storage device 10 depends on the structure of each of these NAND interface circuits 131, 143 and core logic 142, as well as the performance of the removable storage device 10.

[0128] The current consumption value from the third power supply (PWR_3) in the removable storage device 10 is the current consumption value of the physical layer (PHY-A) 141. The current consumption value from the third power supply (PWR_3) in the removable storage device 10 depends on the structure of the physical layer (PHY-A) 141 and the performance of the removable storage device 10.

[0129] Figure 12 This is a diagram showing four examples of power supply structures that can be applied to the removable storage device 10.

[0130] In Example 1, a first power supply (PWR_1) with a voltage of 3.3V or 2.5V is used as the power supply for operating the NAND cell array 132, the physical layer (PHY-A) 141, and the core logic 142. A second power supply (PWR_2) with a voltage of 1.2V is used as the power supply for operating the NAND interface circuits 131 and 143.

[0131] In Example 2, a first power supply (PWR_1) with 3.3V or 2.5V is used as the power supply for operating the memory cell array (NANDCell, NAND cell) 132 and the physical layer (PHY-A) 141. A second power supply (PWR_2) with 1.2V is used as the power supply for operating the core logic 142 and the NAND interface circuits 131, 143.

[0132] In Example 3, a first power supply (PWR_1) with 3.3V or 2.5V is used as the power supply for operating the NAND cell array 132 and the core logic 142. A second power supply (PWR_2) with 1.2V is used as the power supply for operating the NAND interface circuits 131 and 143. A third power supply (PWR_3) with 1.8V is used as the power supply for operating the physical layer (PHY-A) 141.

[0133] In Example 4, a first power supply (PWR_1) with 3.3V or 2.5V is used as the power supply for operating the memory cell array (NANDCell, NAND cell) 132. A second power supply (PWR_2) with 1.2V is used as the power supply for operating the core logic 142 and the NAND interface circuits 131, 143. A third power supply (PWR_3) with 1.8V is used as the power supply for operating the physical layer (PHY-A) 141.

[0134] Next, the current consumption level of the portable storage device 10 with the multi-power supply structure applied in this embodiment will be explained.

[0135] When standardizing the mechanical and electrical specifications of the multi-power-source removable storage device 10, multiple suppliers (multiple device manufacturers) manufacture various device products that meet the same mechanical and electrical specifications as the multi-power-source removable storage device 10. Therefore, in order to ensure the interoperability and replaceability of these various device products with the host, current consumption regulations are necessary.

[0136] In this case, the current consumption of each power source varies depending on the installation of the device. Therefore, defining only a single current consumption specification, and only specifying the maximum current consumption of each power source, will not be the optimal indicator for the development, design, and manufacturing of both the device and the host computer. Furthermore, if only the total power consumption of the device is specified, the current consumption of each power source is unclear, necessitating the installation of power circuits with excessive capacity on the host side, thus causing unnecessary cost increases.

[0137] Therefore, in this embodiment, multiple current consumption levels with different current consumption values ​​are defined. Each of these multiple current consumption levels specifies the current consumption for each power supply.

[0138] For example, for a portable storage device 10 operating with two power supplies, each of the various current consumption levels specifies both the current consumption associated with the first power supply (PWR_1) and the current consumption associated with the second power supply (PWR_2). The portable storage device 10 operating with two power supplies is configured to support one of the various current consumption levels.

[0139] For example, imagine a case where the current consumption level supported by the removable storage device 10 is the first current consumption level, which has the largest current consumption value among a variety of current consumption levels.

[0140] In this case, the first current consumption by the removable storage device 10 from the first power supply (PWR_1) is less than or equal to the maximum current value that the host can supply to the first power supply terminals (P128, P130, P131) of the removable storage device 10 via the contact resistance value between the terminals of the socket 100 and the terminals of the removable storage device 10. In other words, the first allowable current value is the maximum current specified in such a way that the voltage value of each first power supply terminal will not fall below the lower limit voltage value of the first power supply (PWR_1) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance value. Furthermore, the second current consumption by the removable storage device 10 from the second power supply (PWR_2) is less than or equal to the maximum current value that the host can supply to the second power supply terminals (P124, P125, P127) of the removable storage device 10 via the contact resistance value between the terminals of the socket 100 and the terminals of the removable storage device 10. In other words, the second allowable current value is the maximum current specified in a way that the voltage value of each second power supply terminal will not fall below the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance value.

[0141] Imagine a scenario where the current consumption level supported by the removable storage device 10 is one of other current consumption levels that consume less current than the first current consumption level.

[0142] In this case, the first current consumption value consumed by the removable storage device 10 from the first power supply (PWR_1) is below the third allowable current value related to the first power supply (PWR_1) as specified by the other current consumption level, and the second current consumption value consumed by the removable storage device 10 from the second power supply (PWR_2) is below the fourth allowable current value related to the second power supply (PWR_2) as specified by the other current consumption level.

[0143] Therefore, depending on which of the multiple current consumption levels the removable storage device 10 supports, the current consumption value (maximum current consumption value) required for the operation of the removable storage device 10 can be specified for each power supply.

[0144] Therefore, when the removable storage device 10 to be used in the host has a current consumption level of 1, the host manufacturer can adopt a power supply structure in which the host is equipped with a power supply circuit capable of supplying the first and second allowable current consumption values ​​corresponding to the 1st current consumption level. Thus, any device product supporting the 1st current consumption level can be used normally in a host corresponding to the 1st current consumption level.

[0145] In addition, when the current consumption level of the removable storage device 10 to be used in the host is another current consumption level with less current consumption than the first current consumption level, the host manufacturer can optimize the power supply circuit capability of the host side for each power supply based on the allowable current consumption value corresponding to the other current consumption level, thereby reducing the cost of the power supply circuit of the host side.

[0146] Figure 13 It is a diagram representing various current consumption levels.

[0147] In this embodiment, three or four current consumption levels are defined. The current consumption level is also referred to as the "current level".

[0148] In the removable storage device 10 with a two-power-source configuration, for each current level, a maximum current consumption value associated with the first power source (PWR_1) and a maximum current consumption value associated with the second power source (PWR_2) are specified. The maximum current consumption value is specified using the maximum current that can be supplied from the host to the removable storage device 10 via the contact resistance value, i.e., the allowable current value. In other words, for each power source, an allowable current value is specified for each current level.

[0149] In the portable storage device 10 with a 3-power supply structure, for each current level, an allowable current value is specified related to the first power supply (PWR_1), the second power supply (PWR_2), and the third power supply (PWR_3).

[0150] For the first current level CC1, the allowable current value associated with the first power source (PWR_1) is denoted as IP1C1, the allowable current value associated with the second power source (PWR_2) is denoted as IP2C1, and the allowable current value associated with the third power source (PWR_3) is denoted as IP3C1.

[0151] For the second current level CC2, the allowable current value associated with the first power source (PWR_1) is denoted as IP1C2, the allowable current value associated with the second power source (PWR_2) is denoted as IP2C2, and the allowable current value associated with the third power source (PWR_3) is denoted as IP3C2.

[0152] For the third current rating CC3, the allowable current value associated with the first power source (PWR_1) is denoted as IP1C3, the allowable current value associated with the second power source (PWR_2) is denoted as IP2C3, and the allowable current value associated with the third power source (PWR_3) is denoted as IP3C3.

[0153] For current rating CC4, the allowable current value associated with the first power source (PWR_1) is denoted as IP1C4, the allowable current value associated with the second power source (PWR_2) is denoted as IP2C4, and the allowable current value associated with the third power source (PWR_3) is denoted as IP3C4.

[0154] Among the current ratings CC1 to CC4, the current rating with the highest current consumption (permissible current value) is CC1 (current rating 1). The second highest current rating is CC2 (current rating 2). The third highest current rating is CC3 (current rating 3). The lowest current rating is CC4 (current rating 4).

[0155] The permissible current value (PWR permissible current value) of each power supply is calculated taking into account the power supply variability rate (lower limit variability rate) of each power supply and the contact resistance value between the terminals of the removable storage device 10 and the lead terminals of the socket 100. Therefore, the current rating is not only expressed as a rating (1 to 4), but may also be expressed with the following current rating symbols that include parameters representing the power supply variability rate and parameters representing the contact resistance value.

[0156] Current rating symbol: CC#$%

[0157] In this case, # indicates the rating. # represents any one of 1 to 4. $ represents the contact resistance value. The contact resistance value is generally specified for each socket product.

[0158] For example, $ represents one of the following: 3 (=30mΩ), 4 (=40mΩ), 5 (=50mΩ), 6 (=60mΩ), 7 (=70mΩ), and 8 (=80mΩ).

[0159] The percentage indicates the power supply variability (lower limit variability). The power supply variability (lower limit variability) is determined by the performance of the power supply circuitry (power management IC: PMIC) located within the host computer. For example, % represents either 1 (-1% variability) or 2 (-2% variability).

[0160] For the first current level CC1, the allowable current value IP1C1 associated with the first power supply (PWR_1) is expressed by the following formula.

[0161] IP1C1 = PWR_1 allowable current value × N

[0162] The PWR_1 allowable current value represents the allowable current value of the first power supply (PWR_1) for each terminal. The PWR_1 allowable current value is the maximum current specified in a manner that ensures the voltage value at the first power supply terminal will not fall below the lower limit voltage of the first power supply (PWR_1) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance of the device socket. N represents the number of first power supply terminals supplied with the first power supply (PWR_1). For both the -1% and -2% variation cases, six PWR_1 allowable current values ​​corresponding to the six contact resistance values ​​are obtained.

[0163] For the first current level CC1, the allowable current value IP2C1 associated with the second power supply (PWR_2) is expressed by the following formula.

[0164] IP2C1 = PWR_2 allowable current value × M

[0165] The PWR_2 allowable current value represents the allowable current value of the second power supply (PWR_2) for each terminal. The PWR_2 allowable current value is the maximum current specified in a way that the voltage value of the second power supply terminal will not fall below the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance value of the device socket. M represents the number of second power supply terminals supplied with the second power supply (PWR_2). For both the -1% and -2% variation cases, six PWR_2 allowable current values ​​corresponding to the six contact resistance values ​​are obtained.

[0166] For the first current level CC1, the allowable current value IP3C1 associated with the third power supply (PWR_3) is expressed by the following formula.

[0167] IP3C1 = PWR_3 allowable current value × L

[0168] The PWR_3 allowable current value represents the allowable current value of the third power supply (PWR_3) for each terminal. The PWR_3 allowable current value is the maximum current specified in a way that the voltage value of the third power supply terminal will not fall below the lower limit voltage value of the third power supply (PWR_3) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance value of the device socket. L represents the number of third power supply terminals supplied with the third power supply (PWR_3). For both the -1% and -2% variation cases, six PWR_3 allowable current values ​​corresponding to the six contact resistance values ​​are obtained.

[0169] Thus, in this embodiment, for current rating CC1, for both the -1% and -2% variation cases, six permissible current values ​​IP1 (six IP1C1 values) and six permissible current values ​​IP2 (six IP2C1 values) corresponding to the six contact resistance values ​​are specified. Similarly, for current ratings CC2 to CC4, for both the -1% and -2% variation cases, six permissible current values ​​IP1 and six permissible current values ​​IP2 corresponding to the six contact resistance values ​​are also specified.

[0170] For current rating CC1, the six permissible current values ​​IP1 corresponding to the six contact resistance values ​​are calculated based on the nominal voltage value (2.5V) of the first power supply (PWR_1), the power supply variability rate of the first power supply (PWR_1), the lower limit voltage value (e.g., 2.4V) of the first power supply (PWR_1) required for the operation of the removable storage device 10, and the six contact resistance values. The six permissible current values ​​IP1 are calculated based on both a -1% variation and a -2% variation. For details on the calculation examples of the six permissible current values ​​IP1 for the -1% and -2% variation cases, please refer to... Figure 16 As described later.

[0171] Similarly, for current rating CC1, the six permissible current values ​​IP2 corresponding to the six contact resistance values ​​are calculated based on the nominal voltage value (1.2V) of the second power supply (PWR_2), the power supply variation rate of the second power supply (PWR_2), the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10 (e.g., 1.14V), and the six contact resistance values. The six permissible current values ​​IP2 are calculated for both the -1% variation and the -2% variation cases.

[0172] For current rating CC2, the permissible current value IP1 corresponding to any one of the six contact resistance values ​​is specified as the minimum of the following (1) and (2).

[0173] (1) IP1 corresponding to the contact resistance value specified by CC1

[0174] (2) The value obtained by multiplying the largest IP1 among the 6 IP1 types specified by CC1 by the ratio (%) allocated to CC2.

[0175] Here, IP1, as specified by CC1, corresponding to the contact resistance value, is the value obtained by multiplying the PWR_1 allowable current value corresponding to the contact resistance value by the number of first power terminals (N). Additionally, the maximum IP1 is the value obtained by multiplying the maximum value (IP1C1max) among the six PWR_1 allowable current values ​​specified by CC1 by the number of first power terminals (N).

[0176] This ratio is also used as a reference for the allowable current consumption reduction rate or CC current ratio.

[0177] For current rating CC2, the permissible current value IP2 corresponding to any one of the six contact resistance values ​​is specified as the minimum of the following (3) and (4).

[0178] (3) IP1 corresponding to the contact resistance value specified by CC1

[0179] (4) The value obtained by multiplying the largest IP2 among the 6 IP2 types specified by CC1 by the aforementioned ratio (%) allocated to CC2.

[0180] For current rating CC3, the permissible current value IP1 corresponding to any one of the six contact resistance values ​​is specified as the minimum of the following (1) and (2).

[0181] (1) IP1 corresponding to the contact resistance value specified by CC1

[0182] (2) The value obtained by multiplying the largest IP1 among the 6 IP1 types specified by CC1 by the ratio (%) allocated to CC3.

[0183] The percentage (%) allocated to CC3 was set to a value smaller than the percentage (%) allocated to CC2.

[0184] For current rating CC3, the permissible current value IP2 corresponding to any one of the six contact resistance values ​​is specified as the minimum of the following (3) and (4).

[0185] (3) IP2 corresponding to the contact resistance value specified by CC1

[0186] (4) The value obtained by multiplying the largest IP2 among the 6 types of IP2 specified by CC1 by the aforementioned ratio (%) allocated to CC3.

[0187] For current rating CC4, the permissible current value IP1 corresponding to any one of the six contact resistance values ​​is specified as the minimum of the following (1) and (2).

[0188] (1) IP1 corresponding to the contact resistance value specified by CC1

[0189] (2) The value obtained by multiplying the largest IP1 among the 6 IP1 types specified by CC1 by the ratio (%) allocated to CC4.

[0190] The percentage (%) allocated to CC4 was set to a value smaller than the percentage (%) allocated to CC3.

[0191] For current rating CC4, the permissible current value IP2 corresponding to any one of the six contact resistance values ​​is specified as the minimum of the following (3) and (4).

[0192] (3) IP2 corresponding to the contact resistance value specified by CC1

[0193] (4) The value obtained by multiplying the largest IP2 among the 6 types of IP2 specified by CC1 by the aforementioned ratio (%) allocated to CC4.

[0194] Figure 14 This is a graph showing the calculation formula for the current consumption (allowable current) and the allowable current reduction rate corresponding to current ratings CC2 to CC4.

[0195] The allowable current value IP1 of the first power supply (PWR_1) is obtained using the following formula.

[0196] IP1=MIN[IP1C1,IP1C1max×N×ratio]

[0197] That is, when IP1 is below IP1C1max×N×ratio, IP1=IP1C1; when IP1C1 is above IP1C1max×N×ratio, IP1=IP1C1max×N×ratio.

[0198] Here, IP1C1max represents the maximum value among the six permissible current values ​​of PWR_1 specified by CC1. The permissible current value of PWR_1 with a contact resistance of 30mΩ is used as IP1C1max. N represents the number of the first power supply terminals. Therefore, IP1C1max×N represents the maximum IP1 among the six IP1 (IP1C1) values ​​specified by CC1.

[0199] The allowable current value IP2 of the second power supply (PWR_2) is obtained using the following formula.

[0200] IP2=MIN[IP2C1,IP2C1max×M×ratio]

[0201] Here, IP2C1max represents the maximum value among the six permissible current values ​​for PWR_2 specified by CC1. The permissible current value for PWR_2 with a contact resistance of 30mΩ is used as IP2C1max. M represents the number of second power supply terminals. Therefore, IP2C1max×M represents the maximum IP2 among the six IP2 (IP2C1) values ​​specified by CC1.

[0202] The allowable current value IP3 of the third power supply (PWR_3) is obtained using the following formula.

[0203] IP3=MIN[IP3C1,IP3C1max×L×ratio]

[0204] Here, IP3C1max represents the maximum value among the six permissible current values ​​for PWR_3 specified by CC1. The permissible current value for PWR_3 with a contact resistance of 30mΩ is used as IP3C1max. L represents the number of third power supply terminals. Therefore, IP3C1max×L represents the maximum IP3 among the six IP3 (IP3C1) values ​​specified by CC1.

[0205] in addition, Figure 14 The "ratio" indicates a predefined ratio (allowable current reduction rate). In this embodiment, the "ratio" allocated to CC2 is, for example, 72%. The "ratio" allocated to CC3 is, for example, 56%. The "ratio" allocated to CC4 is, for example, 47%.

[0206] Among the current ratings CC2 to CC4, Example 1 can be set to IP1 = IP2, and Example 2 can be set to IP1 ≠ IP2.

[0207] In Example 1, the six IP2 values ​​corresponding to the six contact resistance values ​​are substituted into the six IP1 values ​​corresponding to the six contact resistance values. Therefore, if the IP2 value corresponding to a certain contact resistance value is smaller than the IP1 value corresponding to that contact resistance value, the value of the IP2 value corresponding to that contact resistance value is used as the value of the IP1 value corresponding to that contact resistance value.

[0208] In Example 2, the six IP1 values ​​corresponding to the six contact resistance values ​​and the six IP2 values ​​corresponding to the six contact resistance values ​​are calculated individually, without substituting the IP2 values ​​corresponding to the contact resistance values ​​into the IP1 values ​​corresponding to each contact resistance value.

[0209] Next, we will explain an example of how to calculate the allowable current value of PWR. Figure 15 This is a diagram showing an example of the formula for calculating the current consumption of each power source according to each current level, and an example of the allowable current reduction rate.

[0210] Here, we assume that the maximum PWR current value for each terminal is 1.2A. The maximum PWR current value for each terminal represents the maximum current value that can be supplied to one power terminal of the removable storage device 10 without considering contact resistance and the power supply variability of each power source. In other words, the maximum PWR current value for each terminal is the maximum current value that can flow from the host to one lead terminal of the socket 100.

[0211] Furthermore, here we envision a scenario where the number of first power terminals supplied with the first power source (PWR_1) is 3, the number of second power terminals supplied with the second power source (PWR_2) is 3, and the number of third power terminals supplied with the third power source (PWR_3) is 1.

[0212] The allowable current value IP1C1 of the first power supply (PWR_1) of current rating CC1 is based on...

[0213] IP1C1 = PWR_1 allowable current value × 3

[0214] And thus, it is obtained.

[0215] The permissible current value of PWR_1 is the maximum current specified in such a way as described above, in a manner that ensures the voltage value of the first power supply terminal will not fall below the lower limit voltage value of the first power supply (PWR_1) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance value.

[0216] The allowable current value IP2C1 of the second power supply (PWR_2) of current rating CC1 is based on...

[0217] IP2C1 = PWR_2 allowable current value × 3

[0218] And thus, it is obtained.

[0219] The permissible current value of PWR_2 is the maximum current specified in such a way as described above, in a manner that ensures the voltage value of the second power supply terminal will not fall below the lower limit voltage value of the second power supply (PWR_1) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance value.

[0220] The allowable current value IP3C1 for the third power supply (PWR_3) of current rating CC1 is based on...

[0221] IP3C1 = PWR_3 allowable current value × 1

[0222] And thus, it is obtained.

[0223] The permissible current value of PWR_3 is the maximum current specified in such a way as described above, in that the voltage value of the third power supply terminal will not fall below the lower limit voltage value of the third power supply (PWR_3) required for the operation of the removable storage device 10 due to the voltage drop caused by the contact resistance value.

[0224] In addition, for the allowable current values ​​of PWR_1, PWR_2, and PWR_3, there are...

[0225] PWR allowable current value ≤ PWR maximum current value (e.g., 1.2A)

[0226] The constraints are as follows: Because the voltage drop caused by the contact resistance is smaller when the contact resistance is smaller, the allowable PWR current value can be increased to ensure that the voltage at the power supply terminal does not fall below the lower limit voltage value. However, the maximum value of this allowable PWR current value is limited to the maximum PWR current value (e.g., 1.2A). The maximum value among the six allowable PWR_1 current values ​​corresponding to the six contact resistance values ​​specified by CC1 is equivalent to the allowable PWR_1 current value when the contact resistance value = 30mΩ. This maximum value among the six allowable PWR_1 current values ​​corresponding to the six contact resistance values ​​specified by CC1 is limited to 1.2A. That is, the maximum IP1 among the six IP1 values ​​corresponding to the six contact resistance values ​​specified by CC1 is limited to 3.6A (=3×1.2A). Similarly, the maximum value among the six allowable PWR_2 current values ​​corresponding to the six contact resistance values ​​specified by CC1 is equivalent to the allowable PWR_2 current value when the contact resistance value = 30mΩ. The maximum value of the six permissible PWR_2 values ​​corresponding to the six contact resistance values ​​specified by CC1 is limited to 1.2A. That is, the maximum IP2 among the six IP2 values ​​specified by CC1 is limited to 3.6A (=3×1.2A).

[0227] Next, the permissible current values ​​for each power supply in current rating CC2 will be explained. In current rating CC2, the permissible current reduction rate is, for example, 72%.

[0228] The allowable current value IP1C2 of the first power supply (PWR_1) of current rating CC2 is based on...

[0229] IP1C2=MIN[IP1C1,IP1C1max×3×72%]

[0230] And thus, it is obtained.

[0231] IP1C1max is the maximum value among the six permissible PWR_1 current values ​​specified by CC1, corresponding to six contact resistance values. IP1C1max represents the permissible PWR_1 current value when the contact resistance value is 30mΩ, i.e., the permissible PWR_1 current value at "CC13%".

[0232] The allowable current value IP2C2 of the second power supply (PWR_2) of current rating CC2 is based on...

[0233] IP2C2=MIN[IP2C1,IP2C1max×3×72%]

[0234] And thus, it is obtained.

[0235] IP2C1max is the maximum value among the six permissible PWR_2 current values ​​specified by CC1, corresponding to six contact resistance values. IP2C1max is equivalent to the permissible PWR_2 current value when the contact resistance is 30mΩ. In the case where both the permissible PWR_1 current value and the permissible PWR_2 current value are 1.2A when the contact resistance is 30mΩ, IP2C1max is equal to the permissible PWR_1 current value at "CC13%".

[0236] The allowable current value IP3C2 for the third power supply (PWR_3) of current rating CC2 is based on...

[0237] IP3C2=MIN[IP3C1,IP3C1max×1×72%]

[0238] And thus, it is obtained.

[0239] IP3C1max is the maximum value among the six permissible PWR_3 current values ​​specified by CC1, corresponding to six contact resistance values. IP3C1max is equivalent to the permissible PWR_3 current value when the contact resistance is 30mΩ. In the case where both the permissible PWR_1 current value and the permissible PWR_3 current value are 1.2A when the contact resistance is 30mΩ, IP3C1max is equal to the permissible PWR_1 current value at "CC13%".

[0240] Similar to current rating CC2, IP1C3, IP2C3, and IP3C3 for current rating CC3, and IP1C4, IP2C4, and IP3C4 for current rating CC4 are calculated. In calculating the permissible current values ​​for each power supply in current rating CC3, a permissible current reduction rate is used, for example, 56%. Similarly, in calculating the permissible current values ​​for each power supply in current rating CC4, a permissible current reduction rate is used, for example, 47%.

[0241] Figure 16 This is a diagram showing an example of the allowable current value of PWR_1 for current rating CC1.

[0242] exist Figure 16 In this case, we assume Vps = 2.50V and Vd_min = 2.40V. Vps is the nominal voltage value of the first power supply (PWR_1). Vd_min represents the lower limit voltage value of the first power supply (PWR_1) required for the operation of the removable storage device 10.

[0243] For example, in a case where the contact resistance is 60mΩ and the first power supply (PWR_1) has a variation rate of -2%, the allowable current value of PWR_1 is calculated using the following formula.

[0244] PWR_1 allowable current = (2.5V - 0.05V (2% drop) - 2.4V (Vd_min)) / 60mΩ = 0.83A

[0245] The allowable current value IP1C1 associated with the first power source (PWR_1) is calculated using the following formula.

[0246] IP1C1 = 0.83 × 3 = 2.5A

[0247] Similarly, in the case where the contact resistance is 60mΩ and the variation rate of the first power supply (PWR_1) is -1%, the allowable current value of PWR_1 is calculated using the following formula.

[0248] PWR_1 allowable current = (2.5V - 0.025V (1% drop) - 2.4V (Vd_min)) / 60mΩ = 1.25A

[0249] In this case, based on the constraint that the maximum allowable current of PWR_1 is 1.20A, the allowable current of PWR_1 is specified as 1.20A. Therefore, the allowable current value IP1C1 associated with the first power supply (PWR_1) is 3.6A.

[0250] Figure 17 This is a diagram showing an example of the allowable current value of PWR_2 for current rating CC1.

[0251] exist Figure 17 In this case, we assume Vps = 1.20V and Vd_min = 1.14V. Vps is the nominal voltage value of the second power supply (PWR_2). Vd_min represents the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10.

[0252] For example, in a case where the contact resistance is 60mΩ and the first power supply (PWR_2) has a variation rate of -2%, the allowable current value of PWR_2 is calculated using the following formula.

[0253] PWR_2 (allowable current) = (1.20V - 0.024V (2% drop) - 1.14V (Vd_min)) / 60mΩ = 0.60A

[0254] The allowable current value IP2C1 associated with the second power supply (PWR_2) is calculated using the following formula.

[0255] IP2C1 = 0.60 × 3 = 1.80 A

[0256] Figure 18 For each of the four current levels CC1 to CC4, a graph showing the allowable current ratio for CC1max and the allowable current of each power supply is displayed.

[0257] CC1max is the maximum allowable current value for each power supply in current rating CC1. The allowable current ratio for current rating CC1 is 100%, for current rating CC2 it is 72%, for current rating CC3 it is 56%, and for current rating CC4 it is 47%.

[0258] When the permissible current IP1 of the first power supply (PWR_1) of current rating CC1 is 3.6A, the permissible current IP1 of current rating CC2 is 2.6A, the permissible current IP1 of current rating CC3 is 2.0A, and the permissible current IP1 of current rating CC4 is 1.7A. When the permissible current IP2 of the second power supply (PWR_1) of current rating CC1 is 3.6A, the permissible current IP2 of current rating CC2 is 2.6A, the permissible current IP2 of current rating CC3 is 2.0A, and the permissible current IP2 of current rating CC4 is 1.7A.

[0259] Thus, for each of the multiple levels, as the current consumption associated with the first power supply (PWR_1), multiple permissible current values ​​corresponding to multiple contact resistance values ​​are specified, and as the current consumption associated with the second power supply (PWR_2), multiple permissible current values ​​corresponding to multiple contact resistance values ​​are specified.

[0260] Imagine a current rating of CC1 supported by the removable storage device 10, and the contact resistance between the terminals of the socket 100 and the terminals of the removable storage device 10 is a specific contact resistance value among a variety of contact resistance values.

[0261] In this case, the first current consumption value consumed by the removable storage device 10 from the first power supply (PWR_1) is less than IP1, which corresponds to the specific contact resistance value specified by CC1. That is, it is less than the first permissible current value obtained based on the nominal voltage value (2.5V) of the first power supply (PWR_1), the power supply variability rate of the first power supply (PWR_1), the specific contact resistance value, and the lower limit voltage value (e.g., 2.4V) of the first power supply (PWR_1) required for the operation of the removable storage device 10. Furthermore, the second current consumption value consumed by the removable storage device from the second power supply (PWR_2) is less than IP2, which corresponds to the specific contact resistance value specified by CC1. That is, it is less than the second permissible current value obtained based on the nominal voltage value (1.2V) of the second power supply (PWR_2), the power supply variability rate of the second power supply (PWR_2), the specific contact resistance value, and the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10.

[0262] Imagine that the current level supported by the removable storage device 10 is one of CC2 to CC4, and the contact resistance between the terminal of the socket 100 and the terminal of the removable storage device 10 is that specific contact resistance value.

[0263] In this case, the first current consumption value consumed by the removable storage device 10 from the first power source (PWR_1) is (1) the minimum value among IP1 (i.e., the first permissible current value mentioned above) corresponding to the specific contact resistance value specified by CC1, and (2) the maximum permissible current value (IP1C1max) among the various permissible current values ​​related to the first power source (PWR_1) specified by CC1, multiplied by the ratio allocated to this current level. Furthermore, the second current consumption value consumed by the removable storage device 10 from the second power source (PWR_1) is (3) the minimum value among IP2 (i.e., the second permissible current value mentioned above) corresponding to the specific contact resistance value specified by CC1, and (4) the minimum value among the maximum permissible current value (IP2C1max) among the various permissible current values ​​related to the second power source (PWR_2) specified by CC1, multiplied by the ratio allocated to this current level.

[0264] Next, the current consumption level guidelines used in this embodiment will be explained.

[0265] When combining six contact resistance values ​​(30mΩ, 40mΩ, 50mΩ, 60mΩ, 70mΩ, 80mΩ) with two power supply variation rates (-1% variation, -2% variation) and four current ratings CC1 to CC4, there are 12 categories for each current rating. Therefore, the total number of categories that can be classified according to CCG#$% (#: 1~4, $: 3~8, %: 1~2) is 48.

[0266] CCG#$% is useful as information for identifying removable storage device 10, but for easier identification of removable storage device 10, current consumption level guidance can be used.

[0267] Current consumption rating guidelines are also known as current rating guidelines (CCGs). CCGs define several different combinations of current consumption values ​​and performance characteristics (CCG types). For example, data transfer rate can be used as an indicator of performance.

[0268] Figure 19A It is a diagram showing a list of current rating guidelines for each type of power supply, indicating the permissible current value and the current consumption level guidelines for each device.

[0269] exist Figure 19A For example, in the current rating guideline CCG, four types are defined: CCG-A, CCG-B, CCG-C, and CCG-D. For each of CCG-A (CCG-A, CCG-B, CCG-C, and CCG-D), the current range corresponding to IP1, the current range corresponding to IP2, and the performance are specified.

[0270] In CCG-A, the current range corresponding to IP1 is 2.6A < current range ≤ 3.6A. The current range corresponding to IP2 is also 2.6A < current range ≤ 3.6A. The performance is 4~8GB / s.

[0271] In CCG-B, the current range corresponding to IP1 is 2.0A < current range ≤ 2.6A. The current range corresponding to IP2 is also 2.0A < current range ≤ 2.6A. The performance is 2~5GB / s.

[0272] In CCG-C, the current range corresponding to IP1 is 1.7A < current range ≤ 2.0A. The current range corresponding to IP2 is also 1.7A < current range ≤ 2.0A. The performance is 1~3GB / s.

[0273] In CCG-D, the current range corresponding to IP1 is less than 1.7A. The current range corresponding to IP2 is also less than 1.7A. Performance is less than 23GB / s.

[0274] The 48 current rating classifications represented by CCG#$% (#: 1~4, $: 3~8, %: 1~2) use current rating guidelines to classify CCG into several categories. For example, the 48 current rating classifications are divided into 8 categories: CCG-A(1), CCG-A(2), CCG-B(1), CCG-B(2), CCG-C(1), CCG-C(2), CCG-D(1), and CCG-D(2).

[0275] The classification condition satisfies the following (1) or (2).

[0276] (1) Both IP1 and IP2 fall within Figure 19A the current range.

[0277] (2) Either one of IP1 and IP2 falls within Figure 19A the current range, and the other is a current value below the current range.

[0278] For example, in a case where both IP1 and IP2 of a certain current level classification fall within the current range corresponding to CCG-A, the type of this current level classification is CCG-A(1). In addition, in a case where either one of IP1 and IP2 of a certain current level classification falls within the current range corresponding to CCG-A, and the other is a current value below the current range corresponding to CCG-A, the type of this current level classification is CCG-A(2).

[0279] In addition, when the condition (CCG<IP) that the minimum value (= MIN[IP1, IP2]) of IP1 and IP2 in a certain current level classification exceeds the upper limit current value of a certain current range is satisfied, the type corresponding to this current range can be determined as the type of this current level classification. For example, when the condition that the minimum value (= MIN[IP1, IP2]) of IP1 and IP2 in a certain current level classification exceeds the upper limit current value of the current range corresponding to CCG-B is satisfied, the type of this current level classification is CCG-B.

[0280] Next, the current level and current level guideline (1) when IP1=IP2 and there is a -1% variation, the current level and current level guideline (2) when IP1=IP2 and there is a -2% variation, the current level and current level guideline (1') when IP1≠IP2 and there is a -1% variation, and the current level and current level guideline (2') when IP1≠IP2 and there is a -2% variation will be described.

[0281] Figure 19B is a diagram showing the current level and the current level guideline (1). Figure 19C is a diagram showing the current level and the current level guideline (2). Figure 19C is a diagram showing the current level and the current level guideline (1'). Figure 19D is a diagram showing the current level and the current level guideline (2').

[0282] In the current class and current class guideline (1), the table for CC1 is divided into CC0 (maximum allowable current table) and CC1(1%) (a table of current values rounded to one decimal place and CCG). In the table for CC1(1%), for each of the 6 contact resistance values, an "IP1" column indicating IP1, an "IP2" column indicating IP2, a "TTL" column indicating the sum of these IP1 and IP2, a "CCG" column indicating the CCG type, and a "CCG<IP" column indicating the CCG type based on another classification method are defined. In each of the tables from CC2(1%) to CC4(1%), for each of the 6 contact resistance values, an "IP1" column indicating IP1, an "IP2" column indicating IP2, a "TTL" column indicating the sum of these IP1 and IP2, a "CCG" column indicating the CCG type, and a "CCG<IP" column indicating the CCG type based on another classification method are also defined.

[0283] The 6 types of IP1 in the table for CC1(1%) are calculated based on the nominal voltage value (2.5V) of the first power supply (PWR_1), the power supply variation rate (-1%) of the first power supply (PWR_1), the lower limit voltage value (for example, 2.4V) of the first power supply (PWR_1) required for the operation of the removable storage device 10, and the 6 contact resistance values. The 6 types of IP2 in the table for CC1(1%) are calculated based on the nominal voltage value (1.2V) of the second power supply (PWR_2), the power supply variation rate (-1%) of the second power supply (PWR_2), the lower limit voltage value (for example, 1.14V) of the second power supply (PWR_2) required for the operation of the removable storage device 10, and the 6 contact resistance values.

[0284] In each of the tables from CC2(1%) to CC4(1%), the 6 types of IP2 are based on Figure 15 the formula IP2 = MIN[IP2C1, IP2C1max×M×ratio] described above to calculate. The 6 types of IP1 are calculated such that IP1 = IP2.

[0285] In Figure 19CIn the current class and current class guideline (2), the table for CC1 is also divided into CC0 (maximum allowable current table) and CC1(2%) (a table of current values rounded to one decimal place and CCG). In the table of CC1(2%), for each of the 6 contact resistance values, an "IP1" column indicating IP1, an "IP2" column indicating IP2, a "TTL" column indicating the sum of these IP1 and IP2, a "CCG" column indicating the CCG type, and a "CCG<IP" column indicating the CCG type based on another classification method are defined. In each of the tables from CC2(2%) to CC4(2%), for each of the 6 contact resistance values, an "IP1" column indicating IP1, an "IP2" column indicating IP2, a "TTL" column indicating the sum of these IP1 and IP2, a "CCG" column indicating the CCG type, and a "CCG<IP" column indicating the CCG type based on another classification method are also defined.

[0286] The 6 types of IP1 in the table of CC1(2%) are calculated based on the nominal voltage value of the first power supply (PWR_1) (2.5V), the power supply variation rate of the first power supply (PWR_1) (-2%), the lower limit voltage value of the first power supply (PWR_1) required for the operation of the removable storage device 10 (for example, 2.4V), and the 6 contact resistance values. The 6 types of IP2 in the table of CC1(2%) are calculated based on the nominal voltage value of the second power supply (PWR_2) (1.2V), the power supply variation rate of the second power supply (PWR_2) (-2%), the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10 (for example, 1.14V), and the 6 contact resistance values.

[0287] In each of the tables from CC2(2%) to CC4(2%), the 6 types of IP2 are calculated based on the formula IP2=MIN[IP2C1, IP2C1max×M×ratio]. The 6 types of IP1 are calculated such that IP1=IP2.

[0288] In Figure 19DIn the current class and current class guideline (1'), the table for CC1 is also divided into CC0 (maximum allowable current table) and CC1(1%) (a table representing current values rounded to one decimal place and CCG). In the table of CC1(1%), for each of the 6 contact resistance values, an "IP1" column representing IP1, an "IP2" column representing IP2, a "TTL" column representing the sum of these IP1 and IP2, a "CCG" column representing the CCG type, and a "CCG<IP" column representing the CCG type based on another classification method are defined. In each of the tables from CC2(1%) to CC4(1%), for each of the 6 contact resistance values, an "IP1" column representing IP1, an "IP2" column representing IP2, a "TTL" column representing the sum of these IP1 and IP2, a "CCG" column representing the CCG type, and a "CCG<IP" column representing the CCG type based on another classification method are also defined.

[0289] The 6 types of IP1 in the table of CC1(1%) are calculated based on the nominal voltage value of the first power supply (PWR_1) (2.5V), the power supply variation rate of the first power supply (PWR_1) (-1%), the lower limit voltage value of the first power supply (PWR_1) required for the operation of the removable storage device 10 (for example, 2.4V), and the 6 contact resistance values. The 6 types of IP2 in the table of CC1(1%) are calculated based on the nominal voltage value of the second power supply (PWR_2) (1.2V), the power supply variation rate of the second power supply (PWR_2) (-1%), the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10 (for example, 1.14V), and the 6 contact resistance values.

[0290] In each of the tables from CC2(1%) to CC4(1%), the 6 types of IP1 are based on Figure 15 calculated by the formula IP1 = MIN[IP1C1, IP1C1max×M×ratio] described above. The 6 types of IP2 are calculated by the formula IP2 = MIN[IP2C1, IP2C1max×M×ratio].

[0291] In Figure 19EIn the current class and current class guide (2'), the table for CC1 is also divided into CC0 (maximum allowable current table) and CC1(2%) (a table of current values rounded to one decimal place and CCG). In the table of CC1(2%), for each of the 6 contact resistance values, an "IP1" column indicating IP1, an "IP2" column indicating IP2, a "TTL" column indicating the sum of these IP1 and IP2, a "CCG" column indicating the CCG type, and a "CCG<IP" column indicating the CCG type based on another classification method are defined. In each of the tables from CC2(2%) to CC4(2%), for each of the 6 contact resistance values, an "IP1" column indicating IP1, an "IP2" column indicating IP2, a "TTL" column indicating the sum of these IP1 and IP2, a "CCG" column indicating the CCG type, and a "CCG<IP" column indicating the CCG type based on another classification method are also defined.

[0292] The 6 types of IP1 in the table of CC1(2%) are calculated based on the nominal voltage value of the first power supply (PWR_1) (2.5V), the power supply variation rate of the first power supply (PWR_1) (-2%), the lower limit voltage value of the first power supply (PWR_1) required for the operation of the removable storage device 10 (for example, 2.4V), and the 6 contact resistance values. The 6 types of IP2 in the table of CC1(2%) are calculated based on the nominal voltage value of the second power supply (PWR_2) (1.2V), the power supply variation rate of the second power supply (PWR_2) (-2%), the lower limit voltage value of the second power supply (PWR_2) required for the operation of the removable storage device 10 (for example, 1.14V), and the 6 contact resistance values.

[0293] In each of the tables from CC2(2%) to CC4(2%), the 6 types of IP1 are calculated based on the formula IP1=MIN[IP1C1, IP1C1max×M×ratio]. The 6 types of IP2 are calculated based on the formula IP2=MIN[IP2C1, IP2C1max×M×ratio].

[0294] In each of the current class and current class guide (1), current class and current class guide (2), current class and current class guide (1'), and current class and current class guide (2'), 24 current classes are classified, and based on Figure 19A the current class guide list, the types of current class guides are allocated.

[0295] For example, focusing on the current class CC1 with a power supply variation of -2% and a contact resistance value of 60mΩ ( Figure 19Cof CC162). CC162[IP1, IP2] is [≦2.5A, ≦1.8A]. IP1=2.5A falls within the current range (2.0 to 2.6) of CCG-B, and IP2=1.8A is a current value below the current range (2.0 to 2.6) of CCG-B. Therefore, CCG-B(2) is assigned to CC162. The device corresponding to CC162[IP1, IP2] = [≦2.5A, ≦1.8A] is determined as the device corresponding to CCG-B(2).

[0296] Additionally, for example, focusing on the current class CC4 with a power supply variation of -1% and a contact resistance value of 50mΩ( Figure 19B of CC451). CC451[IP1, IP2] is [≦1.7A, ≦1.7A]. Since 1.7A is included in the current range (<1.7) of CCG-D, CCG-D(1) is assigned to CC451. The device corresponding to CC451[IP1, IP2] = [≦1.7A, ≦1.7A] is determined as the device corresponding to CCG-D(1).

[0297] Alternatively, as described above, the type of current class guideline may be determined using the condition that MIN[IP1, IP2]) exceeds the upper limit current value (CCG<IP). For example, if focusing on Figure 19B of CC151, the minimum value of 3.6A and 2.8A, which is 2.8A, exceeds the upper limit current value 2.6A of CCG-B. Therefore, CCG-B is assigned to the "CCG<IP" column of CC151. In this case, the device corresponding to CC151[IP1, IP2] = [≦3.6A, ≦2.8A] is determined as the device corresponding to CCG-B.

[0298] The current class and current class guideline (1), the current class and current class guideline (2), the current class and current class guideline (1'), and the current class and current class guideline (2') can be utilized in the B2B (Business to Business) environment as follows.

[0299] The host manufacturer determines CC (Current Class) based on the power supply variation rate (1% or 2%) of the power supply circuit for the device, the contact resistance value of the device socket, and the maximum consumable current that can be allocated to the device. Next, the host manufacturer determines CCG in consideration of the requested performance for the removable storage device. Then, the host manufacturer uses RFI (Request For Information) to request a device that satisfies the requested performance and CC from the device manufacturer. A device that satisfies CC is a device that satisfies CCG-A to CCG-D in the "CCG" column or the "CCG<IP" column.

[0300] (Example 1) When the power supply fluctuation rate of the device power supply circuit is 1%, the contact resistance of the device socket is 60mΩ, the device distributed current consumption [IP1,IP2] is [2.4A,2.0A], and the requested performance is 3GB / s, the host manufacturer selects CC261 and requests a device of CCG-B or below in the RFI for the device manufacturer.

[0301] (Example 2) When the power supply fluctuation rate of the device power supply circuit is 2%, the contact resistance of the device socket is 60mΩ, the device distributed current consumption [IP1,IP2] is [1.7A,1.7A], and the requested performance is 2GB / s, the host manufacturer selects CC462 and requests a device below CCG-D in the RFI for the device manufacturer.

[0302] The device manufacturer determined that the current consumption was Figure 19A The current rating guideline list includes CCG-A to D for device product specifications that meet the required performance requirements and are below any of the current ratings.

[0303] (Example 3) For a device with a performance of 2.5 GB / s and a current consumption of IP1 = 2.4 A and IP2 <= 2.0 A, the device manufacturer declares CCG-B, guaranteeing operation within the current consumption corresponding to CCG-B. As a method of declaring CCG-B, methods such as recording CCG-B in the data sheet or marking the device with a CCG-B symbol can be used.

[0304] (Example 4) For a device product with a performance of 2.0 GB / s and a current consumption of IP1 = 1.9 A and IP2 = 1.7 A, the device manufacturer declares CCG-C.

[0305] Alternatively, a flag indicating the current level (CC#$%) can be used instead of a flag indicating the type of current level indication. Furthermore, information indicating the type of current level indication, or information indicating the current level itself, can be stored in a register within the controller 14, which is readable from the host computer.

[0306] Figure 20 This is a diagram showing the markings and two-dimensional barcodes on a surface 22 of the package 11 of the removable storage device 10 in the embodiment, and the markings and two-dimensional barcodes 1003 and 1004 on the housing 1001 of the host.

[0307] In the removable storage device 10, in order to enable users to visually identify the current consumption level or current consumption level guidance supported by the removable storage device 10, a mark and a two-dimensional barcode are marked on a surface 22 of the package 11.

[0308] When the removable storage device 10 supports CC1, a mark 51 on a surface 22 of the package 11 of the removable storage device 10 indicates that the removable storage device 10 supports CC1. Additionally, a two-dimensional barcode 61 on a surface 22 of the removable storage device 10 also indicates that the removable storage device 10 supports CC1. Furthermore, the two-dimensional barcode 61 may contain information indicating the current consumption values ​​of each power supply of the removable storage device 10.

[0309] Alternatively, when the removable storage device 10 is classified as a current consumption level guideline CCG-A, the mark 51 may indicate CCG-A. Additionally, the two-dimensional barcode 61 may indicate that the removable storage device 10 is classified as a current consumption level guideline CCG-A.

[0310] Similarly, when the removable storage device 10 supports CC2, a mark 52 on a surface 22 of the package 11 of the removable storage device 10 indicates that the removable storage device 10 supports CC2.

[0311] Additionally, a two-dimensional barcode 62 on one surface 22 of the removable storage device 10 also indicates that the removable storage device 10 supports CC2. Furthermore, the two-dimensional barcode 62 may contain information indicating the current consumption values ​​of each power source of the removable storage device 10.

[0312] Alternatively, if the removable storage device 10 is classified as a current consumption level guideline CCG-B, the mark 52 may indicate CCG-B. Additionally, the two-dimensional barcode 62 may indicate that the removable storage device 10 is classified as a current consumption level guideline CCG-B.

[0313] When the removable storage device 10 supports CC3, a mark 53 on a surface 22 of the package 11 of the removable storage device 10 indicates that the removable storage device 10 supports CC3. Additionally, a two-dimensional barcode 63 on a surface 22 of the removable storage device 10 indicates that the removable storage device 10 supports CC3. Furthermore, the two-dimensional barcode 63 may contain information indicating the current consumption values ​​of each power supply of the removable storage device 10.

[0314] Alternatively, if the removable storage device 10 is classified as a current consumption level guideline CCG-C, the mark 53 may indicate CCG-C. Additionally, a two-dimensional barcode 63 may indicate that the removable storage device 10 is classified as a current consumption level guideline CCG-C.

[0315] When the removable storage device 10 supports CC4, a mark 54 on a surface 22 of the package 11 of the removable storage device 10 indicates that the removable storage device 10 supports CC4. Additionally, a two-dimensional barcode 64 on a surface 22 of the removable storage device 10 can indicate that the removable storage device 10 supports CC4. Furthermore, the two-dimensional barcode 64 can contain information indicating the current consumption values ​​of each power supply of the removable storage device 10.

[0316] Alternatively, if the removable storage device 10 is classified as CCG-D (Current Consumption Rating Guide), the mark 54 may indicate CCG-D. Additionally, the two-dimensional barcode 64 may indicate that the removable storage device 10 is classified as CCG-D.

[0317] Additionally, a mark 1003 and a two-dimensional barcode 1004 indicating the current consumption level supported by the host can also be marked on the side of the host housing 1001. The mark 1003 and the two-dimensional barcode 1004 can be marked on the same side as the side where the insertion port 1002 of the removable storage device 10 is provided.

[0318] Mark 1003 indicates the current consumption level supported by the host. Additionally, mark 1003 may include information such as the host's contact resistance value, power supply variations, and current consumption level guidance. Two-dimensional barcode 1004 indicates that the removable storage device 10 supports CC4. Additionally, two-dimensional barcode 1004 may include information such as the host's contact resistance value, power supply variations, and current consumption level guidance.

[0319] Alternatively, mark 1003 may indicate a current consumption level guide for classifying the host. Additionally, two-dimensional barcode 1003 may indicate a current consumption level guide for classifying the host.

[0320] Users can identify whether the removable storage device 10 and the host are a usable combination by referring to the markings and two-dimensional barcodes displayed on the removable storage device 10 and the host.

[0321] Figure 21 It is a flowchart showing the sequence of device initialization processes executed in the host.

[0322] First, when the host power is on and the removable storage device 10 is inserted into the host socket 100, or when the host power is turned on before the removable storage device 10 is inserted into the host socket 100, the host begins initialization processing (step S101).

[0323] The host reads the CC value in the buffer of the removable storage device 10 (step S102). The buffer is located in the controller 14 and can store information indicating the current consumption level supported by the removable storage device 10, or the current consumption value related to the first power supply (PWR_1), the current consumption value related to the second power supply (PWR_2), and information on the current consumption level categories that classify the removable storage device 10.

[0324] The host checks whether normal operations can be performed (step S103).

[0325] If the number of the current consumption level supported by the host is smaller than the number of the current consumption level supported by the removable storage device 10 (host CC ≦ device CC in step S103), the host ends the initialization process (step S104).

[0326] On the other hand, when the number of the current consumption level supported by the host is greater than the number of the current consumption level supported by the removable storage device 10 (host CC > device CC in step S103), the host will turn off the power to the removable storage device 10 (step S105). This is because the current value of each power supply available to the host is smaller than the current value of each power supply requested by the removable storage device 10.

[0327] Then, when the user replaces the removable storage device 10 inserted into the host (step S106), the host starts the initialization process again (step S101).

[0328] Figure 22 This is a diagram showing a notch in the package 11 of the removable storage device 10 in the embodiment for identifying the current consumption level supported by the removable storage device 10.

[0329] The removable storage device 10 may have a notch as a mechanism for the host to identify the current consumption level supported by the removable storage device 10.

[0330] The removable storage device 10 supporting CC1 has a notch 71 on one side 32 of the package 11, the removable storage device 10 supporting CC2 has a notch 72 on one side 32 of the package 11, and the removable storage device 10 supporting CC3 has a notch 73 on one side 32 of the package 11. Each of the notches included in the package 11 can be provided on any side of the package 11 as long as it does not affect any of the terminals of the removable storage device 10.

[0331] Additionally, for example, two switches can be installed in the socket 100 to identify the four current consumption levels CC1 to CC4. These switches can detect a gap when the portable storage device 10 is inserted into the socket 100.

[0332] The host computer identifies the current consumption level of the removable storage device 10 inserted into the socket 100 based on the combination of the on and off states of the two switches.

[0333] In addition, the information identified by the gap can be used to classify the current consumption levels of removable storage devices into 10 categories.

[0334] Figure 23 This is a diagram showing examples of the power supply structure on the host side corresponding to the four current levels.

[0335] exist Figure 23 The text indicates the state in which a removable storage device 10 supporting various current consumption levels is inserted into a socket 100 on the printed circuit board substrate of the host computer.

[0336] The printed circuit board substrate of the host includes a socket 100, a power management integrated circuit (PMIC) 501 for supplying a first power supply (PWR_1) to the removable storage device 10, and a power management integrated circuit (PMIC) 502 for supplying a second power supply (PWR_2) to the removable storage device 10.

[0337] When the removable storage device 10 and the host support a current consumption level of CC1, the allowable current consumption reduction rate of CC1 is 100% for the current consumption value related to the first power supply and also 100% for the current consumption value related to the second power supply. The removable storage device 10 and the host are designed with their respective supported current consumption levels in mind. Therefore, the first power supply circuit (PMIC) 501 and the second power supply circuit (PMIC) 502 on the printed circuit board substrate of the host are designed to output a current corresponding to the current consumption specified by CC1.

[0338] Furthermore, when the removable storage device 10 and the host support a current consumption level of CC2, the permissible current consumption reduction rate is 72%. The removable storage device 10 and the host are designed with their respective supported current consumption levels in mind. Therefore, the first power supply circuit (PMIC) 601 and the second power supply circuit (PMIC) 602 on the host's printed circuit board substrate are designed to output a current corresponding to the current consumption specified by CC2. That is, in the design of a host supporting CC2, by pre-designing the output current value of the first power supply circuit (PMIC) 601 to be lower than the output current value of the first power supply circuit (PMIC) 501 of CC1, the first power supply circuit (PMIC) 601 can be prevented from exceeding specifications, thereby achieving cost reduction and optimization.

[0339] In addition, the first power supply circuit (PMIC) 601 can also be implemented with a lower output current value than the first power supply circuit (PMIC) 501, thereby miniaturizing the area occupied by the power supply circuit in the printed circuit substrate of the host.

[0340] When the removable storage device 10 and the host support a current consumption level of CC3, the permissible current consumption reduction rate is 56%. The removable storage device 10 and the host are designed with the current consumption level supported by each in mind. Therefore, the first power supply circuit (PMIC) 701 and the second power supply circuit (PMIC) 702 on the printed circuit board substrate of the host are designed to output current corresponding to the current consumption specified by CC3. That is, in the design of the host supporting CC3, by pre-designing the output current values ​​of the first power supply circuit (PMIC) 701 and the second power supply circuit (PMIC) 702 to be lower than the output current values ​​of the first power supply circuit (PMIC) 501 and the second power supply circuit (PMIC) 502 of CC1, it is possible to prevent the first power supply circuit (PMIC) 701 and the second power supply circuit (PMIC) 702 from becoming out of specification, thereby seeking cost reduction and optimization.

[0341] Furthermore, the first power supply circuit (PMIC) 701 and the second power supply circuit (PMIC) 702 can also be implemented with lower output current values ​​than the first power supply circuit (PMIC) 501 and the second power supply circuit (PMIC) 502, thereby miniaturizing the area occupied by the power supply circuits on the printed circuit board substrate of the host. Furthermore, the second power supply circuit (PMIC) 702 is expected to be implemented in a smaller scale than the second power supply circuit (PMIC) 602 of CC2. Therefore, the area occupied by the power supply circuits on the printed circuit board substrate of the host supporting CC3 is expected to be smaller than the area occupied by the power supply circuits on the printed circuit board substrate of the host supporting CC2.

[0342] Furthermore, when the removable storage device 10 and the host support a current consumption level of CC4, the allowable current consumption reduction rate of CC4 is 47%. The removable storage device 10 and the host are designed with their respective supported current consumption levels in mind. Therefore, the first power supply circuit (PMIC) 801 and the second power supply circuit (PMIC) 802 on the printed circuit board substrate of the host are designed to output current corresponding to the current consumption specified by CC4. That is, in the design of the host supporting CC4, by pre-designing the output current values ​​of the first power supply circuit (PMIC) 801 and the second power supply circuit (PMIC) 802 to be lower than the output current values ​​of the first power supply circuit (PMIC) 501 and the second power supply circuit (PMIC) 502 of CC1, it is possible to prevent the first power supply circuit (PMIC) 801 and the second power supply circuit (PMIC) 802 from becoming out of specification, thereby seeking cost reduction and optimization.

[0343] Furthermore, the first power supply circuit (PMIC) 801 and the second power supply circuit (PMIC) 802 can also be implemented with lower output current values ​​than the first power supply circuit (PMIC) 501 and the second power supply circuit (PMIC) 502, thereby miniaturizing the area occupied by the power supply circuits on the printed circuit board substrate of the host. Furthermore, the first power supply circuit (PMIC) 801 is expected to be implemented in a smaller scale than the first power supply circuit (PMIC) 701 of CC3. Therefore, the area occupied by the power supply circuits on the printed circuit board substrate of the host supporting CC4 is expected to be smaller than the area occupied by the power supply circuits on the printed circuit board substrate of the host supporting CC3.

[0344] That is, by knowing in advance the current consumption level of the host machine, the size of the power supply circuit can be optimized.

[0345] Figure 24 This is a diagram showing the heat dissipation path of the device.

[0346] For a general device 200, the heat generated by the operation of the device 200 is mainly dissipated along three heat dissipation paths (1) to (3).

[0347] (1) is the path through which heat is conducted to the upper part of the surface of the package of the device 200 and heat is transferred from the package to the air.

[0348] (2) is the path of heat transfer from PCB to air via heat conduction through the terminals of the connecting device 200 and the PCB.

[0349] (3) is the path of heat conduction to the side surface of the package of device 200 and heat transfer from the package to the air.

[0350] When no heat-conducting components such as TIM (thermal interface material) are installed on the upper surface of the package, (2) becomes the main heat dissipation path for the heat generated in the device 200.

[0351] Figure 25 This is a diagram illustrating an example of the heat dissipation mechanism on the host side, corresponding to a power supply structure with a current consumption level corresponding to the maximum current consumption.

[0352] In the power supply configuration of the host supporting current consumption level CC1, the current consumption is the highest. Therefore, it is assumed that the amount of heat generated from the removable storage device 10 is greater compared to other current consumption levels. Therefore, countermeasures such as installing heat conduction components like TIM 500 can be pre-designed.

[0353] on the other hand, Figure 26 This is a diagram illustrating an example of a heat dissipation mechanism on the host side, corresponding to a power supply structure with a low current consumption level.

[0354] In the power supply configuration of a host supporting current consumption level CC4, the current consumption is lower compared to the power supply configuration of a host supporting CC1. Therefore, compared to the case where the removable storage device 10 supports CC1, the amount of heat generated by the operation of the removable storage device 10 supporting CC4 is less. Therefore, it is not necessary to prepare as... Figure 25 Heat transfer components such as TIM 500.

[0355] In other words, by taking into account the current consumption level, the required heat dissipation design of the host's printed circuit board substrate can be determined, thus avoiding wasted costs due to excessive measures.

[0356] As explained above, according to this embodiment, multiple current levels with different current consumption are specified. For each power source of the multi-power supply structure of the portable storage device 10, a current consumption (allowable current value) is specified. When the current level supported by the portable storage device 10 is CC1, the first current consumption value consumed by the portable storage device 10 from the first power source (PWR_1) is the maximum current value that can be supplied from the host to the first power supply terminals (P128, P130, P131) of the portable storage device 10 via the contact resistance value between the terminals of the socket 100 and the terminals of the portable storage device 10, i.e., the first allowable current value. In addition, the second current consumption value consumed by the removable storage device 10 from the second power supply (PWR_2) is less than or equal to the maximum current value that can be supplied from the host to the second power supply terminals (P124, P125, P127) of the removable storage device 10 via the contact resistance value between the terminals of the socket 100 and the terminals of the removable storage device 10.

[0357] When the current consumption level supported by the removable storage device 10 is one of CC2 to CC4, the first current consumption value consumed by the removable storage device 10 from the first power supply (PWR_1) is less than or equal to the third allowable current value related to the first power supply (PWR_1) as specified by the CC level, and the second current consumption value consumed by the removable storage device 10 from the second power supply (PWR_2) is less than or equal to the fourth allowable current value related to the second power supply (PWR_2) as specified by the other current consumption level.

[0358] Therefore, depending on which of the various current levels the removable storage device 10 supports, the current consumption value (maximum current consumption value) required for the operation of the removable storage device 10 can be specified for each power supply.

[0359] Therefore, when the removable storage device 10 to be used in the host has a current consumption level of CC1, the host manufacturer can adopt a power supply structure that includes power supply circuits in the host capable of supplying the first and second allowable current consumption values ​​corresponding to CC1. Thus, any device product supporting CC1 can be used normally in a host compatible with CC1.

[0360] In addition, when the current rating of the removable storage device 10 to be used in the host is any one of CC2 to CC4, which consumes less current than CC1, the host manufacturer can optimize the power supply circuit capability on the host side for each power supply based on the allowable current consumption value of each power supply corresponding to that current rating, thereby reducing the cost of the power supply circuit on the host side.

[0361] Several embodiments of the present invention have been described, but these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments or variations thereof are included in the scope or spirit of the invention, and are included within the scope of the invention described in the claims and their equivalents.

[0362] Symbol Explanation

[0363] 10···Removable storage device, 13···NAND flash memory, 14···Controller, 100···Socket, first power terminal···P128, P130, P131, second power terminal···P124, P125, P127.

Claims

1. A removable storage device that can be inserted into and removed from a socket in a host computer and operated by first and second power supplies supplied from the host computer, the first and second power supplies having different voltages; And the removable storage device includes: Multiple terminals, including: one or more first power supply terminals supplied with the first power supply, and one or more second power supply terminals supplied with the second power supply; Non-volatile memory; and The controller controls the non-volatile memory; and The removable storage device is configured to support one of a plurality of current consumption levels, each of which specifies a different current consumption level, wherein both a current consumption associated with the first power source and a current consumption associated with the second power source are specified. When the current consumption level supported by the removable storage device is the first current consumption level with the largest current consumption value among the multiple current consumption levels, the first current consumption value consumed by the removable storage device from the first power source is less than or equal to the maximum current value that the host can supply to the more than one first power source terminal of the removable storage device, i.e., the first permissible current value, which is the contact resistance value between the terminal of the socket and the terminal of the removable storage device. The second current consumption value consumed by the removable storage device from the second power source is less than or equal to the maximum current value that the host can supply to the more than one second power source terminal of the removable storage device, i.e., the second permissible current value, which is the contact resistance value. When the current consumption level supported by the removable storage device is another current consumption level different from the first current consumption level, the first current consumption value is below the third allowable current value related to the first power supply as specified by the other current consumption level, and the second current consumption value is below the fourth allowable current value related to the second power supply as specified by the other current consumption level.

2. The removable storage device according to claim 1, wherein the first permissible current value is obtained based on the nominal voltage value of the first power supply, the power supply variability rate of the first power supply, the contact resistance value, and the lower limit voltage value of the first power supply required for operation of the removable storage device.

3. The removable storage device according to claim 2, wherein the second permissible current value is obtained based on the nominal voltage value of the second power supply, the power supply variability rate of the second power supply, the contact resistance value, and the lower limit voltage value of the second power supply required for the operation of the removable storage device.

4. The removable storage device according to claim 1, wherein the first permissible current value is a value obtained by multiplying the permissible current value of the first power supply at each power supply terminal by the number of the first power supply terminals; and The allowable current value of the first power supply at each power terminal is obtained based on the nominal voltage value of the first power supply, the power supply variability rate of the first power supply, the contact resistance value, and the lower limit voltage value of the first power supply required for the operation of the removable storage device.

5. The removable storage device according to claim 4, wherein the second allowable current value is a value obtained by multiplying the allowable current value of the second power supply at each power supply terminal by the number of the second power supply terminals; and The allowable current value of the second power supply at each power terminal is obtained based on the nominal voltage value of the second power supply, the power supply variability rate of the second power supply, the contact resistance value, and the lower limit voltage value of the second power supply required for the operation of the removable storage device.

6. The removable storage device of claim 1, wherein information representing the current consumption level supported by the removable storage device, or information representing one of a variety of categories of the removable storage device based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device, is stored in a cache within the controller that can be read from the host.

7. The removable storage device of claim 1, wherein a mark indicating a current consumption level supported by the removable storage device, or a mark indicating one of a variety of categories of the removable storage device based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device, is marked on a surface of the package of the removable storage device.

8. The removable storage device of claim 1, wherein a two-dimensional barcode representing information related to the one current consumption level supported by the removable storage device, or a two-dimensional barcode representing information related to one of a variety of categories of the removable storage device based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device, is marked on a surface of the package of the removable storage device.

9. The removable storage device of claim 1, wherein a notch is formed in the package of the removable storage device for identifying one of a variety of types of removable storage devices, either supported by the one current consumption level or classified based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device.

10. A removable storage device that can be inserted into and removed from a socket in a host computer and operated by first and second power supplies supplied from the host computer, the first and second power supplies having different voltages; And the removable storage device includes: Multiple terminals, including: one or more first power supply terminals supplied with the first power supply, and one or more second power supply terminals supplied with the second power supply; Non-volatile memory; and The controller controls the non-volatile memory; and The removable storage device is configured to support one of a variety of current consumption levels. Among the various current consumption levels, as the current consumption related to the first power supply, a variety of permissible current values ​​corresponding to a variety of contact resistance values ​​are defined, and as the current consumption related to the second power supply, a variety of permissible current values ​​corresponding to the various contact resistance values ​​are defined. When the current consumption level supported by the removable storage device is the first current consumption level with the largest current consumption value among the plurality of current consumption levels, and the contact resistance between the terminal of the socket and the terminal of the removable storage device is the first contact resistance value among the plurality of contact resistance values, the first current consumption value consumed by the removable storage device from the first power source is below the first allowable current value obtained based on the nominal voltage value of the first power source, the power supply variability rate of the first power source, the first contact resistance value, and the lower limit voltage value of the first power source required for the operation of the removable storage device; and the second current consumption value consumed by the removable storage device from the second power source is below the second allowable current value obtained based on the nominal voltage value of the second power source, the power supply variability rate of the second power source, the first contact resistance value, and the lower limit voltage value of the second power source required for the operation of the removable storage device. When the current consumption level supported by the removable storage device is another current consumption level different from the first current consumption level, and the contact resistance between the terminal of the socket and the terminal of the removable storage device is the first contact resistance value, the first current consumption value is (1) the first allowable current value and (2) the minimum value among the largest allowable current value of the multiple allowable current values ​​related to the first power supply as defined by the first current consumption level multiplied by the ratio allocated to the other current consumption levels, and the second current consumption value is (3) the second allowable current value and (4) the minimum value among the largest allowable current value of the multiple allowable current values ​​related to the second power supply as defined by the first current consumption level multiplied by the ratio.

11. The removable storage device of claim 10, wherein information representing the current consumption level supported by the removable storage device, or information representing one of a variety of categories of the removable storage device based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device, is stored in a cache within the controller that can be read from the host.

12. The removable storage device of claim 10, wherein a mark indicating a current consumption level supported by the removable storage device, or a mark indicating one of a variety of categories in which the removable storage device is classified based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device, is marked on a surface of the package of the removable storage device.

13. The removable storage device of claim 10, wherein a two-dimensional barcode representing information related to the one current consumption level supported by the removable storage device, or a two-dimensional barcode representing information related to one of a variety of categories of the removable storage device based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device, is marked on a surface of the package of the removable storage device.

14. The removable storage device of claim 10, wherein a notch is formed in the package of the removable storage device for identifying one of a variety of types of removable storage devices, either supported by the one current consumption level or classified based on the first and second current consumption values ​​of the removable storage device and the performance of the removable storage device.

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