Information processing device

Abstract

Restores power supply that was interrupted by a protective action. [Solution] The information processing device 10 includes a converter 11, a fan 12, and a processor 13. The converter 11 converts a first DC having a first voltage to a second DC having a second voltage different from the first voltage. The converter 11 stops the output of the second DC in response to the detection of an abnormal current and restarts the output in response to the reception of an enable signal 15. The fan 12 rotates using the second DC. The processor 13 acquires data 14 of the fan 12's rotation speed per unit time and controls the converter 11 to send an enable signal 15 in response to the detection of a fan error indicating that the rotation speed is below a threshold.

Description

Technical Field

[0001] The present invention relates to an information processing apparatus.

Background Art

[0002] An information processing apparatus receives direct current (DC) converted from alternating current (AC), and operates various hardware components using the DC. For example, a notebook personal computer (PC) charges a battery using the DC output from an AC adapter, and uses the power supplied from the AC adapter or the battery.

[0003] In an information processing apparatus, there may be a mixture of hardware components that operate at different DC voltages. For example, a central processing unit (CPU) and a universal serial bus (USB) interface may operate at different DC voltages. Therefore, an information processing apparatus may include a DC-DC converter (DDC) that converts DC of one voltage to DC of another voltage. For example, the DDC may convert DC of about 18 V from 12 volts (V) output by an AC adapter to DC of 5 V.

[0004] There is also a technology in which a charging device that charges a battery detects an overcurrent generated by a short circuit between the positive electrode and the negative electrode, and automatically stops the current flowing from the power source to the positive electrode. In addition, there is a technology in which a tablet PC connected to another electronic device monitors the voltage of a connection terminal and starts supplying power to the other electronic device when a certain voltage change is detected.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] If a DC-DC detects an abnormal current, such as an overcurrent, it may perform a protective action that shuts off the DC output for safety. This protective action may occur when the information processing device is powered on, and there is a low probability that it may occur when the information processing device is turned on for the first time after manufacturing. However, since DDCs are sometimes designed to operate continuously, once a protective action occurs, the device may remain stopped until an explicit recovery procedure is performed.

[0007] One possible approach is for the processor to monitor the DDC's status and restore it if it is not functioning correctly. However, adding control lines or ports to allow the processor to directly monitor the DDC's status can be difficult due to hardware design constraints. Therefore, in one aspect, the present invention aims to restore power supply that has been interrupted by a protective action. [Means for solving the problem]

[0008] In one aspect, an information processing device is provided, which includes a converter that converts a first DC having a first voltage to a second DC having a second voltage different from the first voltage, the converter stopping the output of the second DC in response to the detection of an abnormal current and restarting the output in response to the reception of an enable signal; a fan that rotates using the second DC; and a processor that acquires data on the fan's rotation speed per unit time and controls the converter to send an enable signal in response to the detection of a fan error indicating that the rotation speed is below a threshold. [Effects of the Invention]

[0009] On one hand, the power supply that was interrupted by the protective action is restored. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram illustrating the information processing device of the first embodiment. [Figure 2] This figure shows an example of the hardware of the information processing device according to the second embodiment. [Figure 3] This figure shows an example of how to connect hardware components related to DDC. [Figure 4] This figure shows an example of recovery from a DDC protection operation. [Figure 5] This figure shows an example of how to determine if a fan is faulty. [Figure 6] This flowchart shows an example of the DDC control procedure. [Modes for carrying out the invention]

[0011] This embodiment will be described below with reference to the drawings. (a) First embodiment Figure 1 is a diagram illustrating an information processing device of the first embodiment. The information processing device 10 of the first embodiment is a computer that can operate on battery power, such as a notebook PC or a tablet PC. The information processing device 10 has a converter 11, a fan 12, and a processor 13.

[0012] Converter 11 converts a first DC having a first voltage into a second DC having a second voltage different from the first voltage. Converter 11 may also be called a DC / DC converter or DDC. The second voltage, which is the output voltage, may be lower than the first voltage, which is the input voltage. For example, the first voltage may be around 12V to 18V, and the second voltage may be 5V. Converter 11 may also be called a step-down converter. Converter 11 may also be a linear regulator or a switching regulator.

[0013] Converter 11 may receive DC power from an AC / DC converter. The AC / DC converter may be an AC adapter connected to the information processing device 10. Alternatively, converter 11 may receive DC power from a battery in the information processing device 10. Converter 11 supplies power to some of the hardware components of the information processing device 10. If there is power remaining in the battery, converter 11 may continuously supply power to some hardware components even when the processor 13 is not operating. For this reason, converter 11 is sometimes called an always-on power supply.

[0014] Converter 11 has a protection circuit to protect other hardware components from abnormal currents. Converter 11 detects abnormal currents such as overcurrents. Abnormal currents may be detected when the information processing device 10 is powered on, or when DC is input to converter 11 for the first time after manufacturing. During the first power-on after manufacturing, temporary overcurrents may occur due to the design and manufacturing of various electronic circuits. Converter 11 automatically stops the second DC output in response to the detection of an abnormal current.

[0015] Furthermore, the converter 11 is connected to an enable signal line that transmits the enable signal 15. The enable signal 15 may be a pulse signal. The converter 11 restarts the second DC output in response to the reception of the enable signal. The converter 11 may perform a toggle process that switches the output ON and OFF each time it receives the enable signal 15.

[0016] Fan 12 is an air-cooling component that cools the processor 13. Fan 12 rotates using the second DC output from converter 11 while the processor 13 is operating. Because the processor 13 generates a lot of heat, it is normally abnormal for the processor 13 to be operating but the fan 12 not to be rotating. In addition to fan 12, converter 11 may also supply power to other hardware components. For example, converter 11 may supply power to the USB PD (Power Delivery) circuit.

[0017] Processor 13 executes program instructions. Processor 13 may be referred to as a CPU or an MPU (Micro Processing Unit). When the information processing device 10 is turned on, processor 13 reads the BIOS (Basic Input Output System) program stored in the non-volatile memory into a volatile memory such as RAM (Random Access Memory) and executes the BIOS program. Processor 13 may execute the control of the converter 11 described below according to the BIOS program.

[0018] Processor 13 usually operates at a voltage different from the output of converter 11. Therefore, power is supplied to processor 13 through a path different from that of fan 12. When converter 11 automatically stops due to a protection operation, although fan 12 is not operating, processor 13 may be operating normally.

[0019] The information processing device 10 may have another processor different from processor 13 in order to efficiently control the hardware components related to power supply. The other processor may be referred to as an EC (Embedded Controller). The other processor may be connected to processor 13 via a control signal line, and may also be connected to fan 12 via a control signal line. Further, the other processor may be connected to converter 11 via an enable signal line.

[0020] Processor 13 detects that converter 11 has stopped due to a protection operation and restores converter 11 as follows. Processor 13 acquires data 14. Data 14 indicates the number of rotations of fan 12 per unit time. Processor 13 may measure the number of rotations. Also, another processor such as an EC may measure the number of rotations, and processor 13 may read data 14 from the other processor via a control signal line.

[0021] The processor 13 detects a fan error based on the data 14, indicating that the rotational speed is below a threshold. The threshold may be 0, and the fan error may indicate that the fan 12 is not rotating. If the fan 12 is not rotating, the data 14 may indicate that the rotational speed is 0. Alternatively, if the fan 12 is not rotating, the data 14 may indicate that a fan error has occurred.

[0022] The processor 13 controls the converter 11 to send an enable signal 15 in response to the detection of a fan error. The processor 13 may send the enable signal 15 to the converter 11 via the enable signal line. Alternatively, the processor 13 may request other processors to restore the converter 11 via the control signal line, and the other processors may send the enable signal 15 to the converter 11 via the enable signal line.

[0023] As described above, the information processing device 10 of the first embodiment includes a converter 11, a fan 12, and a processor 13. The converter 11 converts a first DC having a first voltage to a second DC having a second voltage different from the first voltage. The converter 11 stops the output of the second DC in response to the detection of an abnormal current and restarts the output in response to the reception of an enable signal 15. The fan 12 rotates using the second DC.

[0024] The processor 13 acquires data 14 of the fan 12's rotational speed per unit time and controls the converter 11 to send an enable signal 15 in response to the detection of a fan error indicating that the rotational speed is below a threshold.

[0025] This automatically restores the power supply that was interrupted by the protection operation of the converter 11, resolving the problem of hardware components that use the output of the converter 11 not working. In particular, when the information processing device 10 is turned ON for the first time after manufacturing, a temporary overcurrent may occur due to design or manufacturing reasons, causing the protection circuit of the converter 11 to activate. Even in such a case, the information processing device 10 can recover from the failure without the need for engineer intervention, such as by inserting or removing the battery or manually inputting the enable signal 15.

[0026] Furthermore, the information processing device 10 does not need to have control signal lines or control ports for directly monitoring the state of the converter 11. This saves on the number of ports used and circuit area, simplifying the hardware design of the information processing device 10. In addition, the information processing device 10 estimates the state of the converter 11 by using data 14 related to the fan 12, which is one of the typical hardware components that receives power from the converter 11. As a result, the processor 13 can detect the failure of the converter 11 in a general-purpose and efficient manner.

[0027] (b) Second embodiment Figure 2 shows an example of the hardware of the information processing device according to the second embodiment. The information processing device 100 of the second embodiment is a notebook PC. The information processing device 100 has a CPU 101, RAM 103, display 104, chipset 105, SSD (Solid State Drive) 106, BIOS memory 107, input device 108, communication interface 109, and USB interface 110. The information processing device 100 also has an EC 111, PD circuit 114, fan 115, DDC 116, and charging circuit 117.

[0028] Note that the information processing device 100 corresponds to the information processing device 10 of the first embodiment. The DDC 116 corresponds to the converter 11 in Figure 1. The fan 115 corresponds to the fan 12 in Figure 1. The CPU 101 corresponds to the processor 13 in Figure 1.

[0029] The CPU 101 is a processor that executes instructions contained in a program. When the power button is pressed while the CPU 101 is OFF, it reads and executes the BIOS program from the BIOS memory 107. The CPU 101 then reads and executes the OS (Operating System) program from the SSD 106 according to the BIOS program. Furthermore, the CPU 101 then reads and executes the application program from the SSD 106 according to the OS program. The information processing device 100 may have multiple processors.

[0030] The CPU 101 has a GPU (Graphics Processing Unit) 102. The GPU 102 performs image processing and outputs the image to the display 104. The GPU 102 may also be connected to the CPU 101 as an external hardware component.

[0031] RAM 103 is a volatile semiconductor memory that temporarily stores programs and other data used by the CPU 101. The information processing device 100 may have a type of volatile memory other than RAM. Furthermore, RAM 103 may also be used as GPU memory, or the information processing device 100 may have separate GPU memory in addition to RAM 103.

[0032] The display 104 is a display device that displays images such as an operation screen. The display 104 is, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display. An external display may be connected to the information processing device 100.

[0033] The chipset 105 is an integrated circuit that connects the CPU 101 to peripheral devices. The chipset 105 may also be called a hub or bridge. Alternatively, the chipset 105 may be included in the CPU 101. The CPU 101, SSD 106, BIOS memory 107, input device 108, communication interface 109, USB interface 110, and EC111 are connected to the chipset 105.

[0034] SSD106 is a non-volatile storage device that stores software programs such as OS programs and application programs, as well as other data. However, SSD106 is one of the peripheral devices recognized by CPU101 through the BIOS program and becomes accessible after the BIOS program is executed. The information processing device 100 may also have other types of non-volatile storage, such as an HDD (Hard Disk Drive).

[0035] BIOS memory 107 is non-volatile memory that stores the BIOS program. BIOS memory 107 may be read-only memory (ROM) in the strict sense, which cannot be rewritten, or it may be rewritable memory such as flash memory.

[0036] When the CPU 101 is reset, it first reads the BIOS program from a predetermined memory address in the BIOS memory 107. The BIOS program includes instructions for recognizing peripheral devices possessed by the information processing device 100, and instructions for reading the OS program from the recognized non-volatile storage. As will be described later, the BIOS program in the second embodiment also includes instructions for controlling the DDC 116. The BIOS memory 107 also stores the firmware executed by the EC 111.

[0037] The input device 108 generates an input signal indicating user operation and notifies the CPU 101. The input device 108 is, for example, a keyboard, touchpad, or touch panel. The information processing device 100 may have multiple input devices. Furthermore, an external input device such as a mouse may be connected to the information processing device 100.

[0038] The communication interface 109 communicates with other information processing devices via a network. The communication interface 109 may be a wired communication interface with a LAN (Local Area Network) port. Alternatively, the communication interface 109 may be a wireless communication interface that communicates wirelessly with wireless communication devices such as base stations and access points.

[0039] The USB interface 110 has USB ports for connecting to external USB devices. The USB interface 110 sends and receives data signals and control signals to and from the connected USB device. The USB ports have charging signal lines (VBUS) that can supply power. The USB interface 110 may have multiple USB ports with different power supply methods and terminal shapes, such as so-called Type A and Type C.

[0040] For example, with a Type A USB port, power is supplied from the information processing device 100 to the USB device. With a Type C USB port, power is supplied in one direction or the other, depending on the type of USB device connected. Power may be supplied from the information processing device 100 to the USB device, or power may be supplied from the USB device to the information processing device 100. The USB interface 110 of the second embodiment has a PD function that enables the supply of a large amount of power with respect to the Type C USB port.

[0041] A USB device may be a storage device such as an HDD, SSD, or flash memory. Alternatively, a USB device may be a read drive into which optical discs such as CDs (Compact Discs) or DVDs (Digital Versatile Discs) are inserted. Therefore, the USB interface 110 may read programs and other data recorded on the recording medium and store such programs and other data in the volatile memory or non-volatile storage provided by the information processing device 100.

[0042] A program read from a recording medium may be executed by the CPU 101. As described above, the recording medium may be a portable recording medium such as flash memory or an optical disc, and may be used for distributing programs and other data. Such recording media are sometimes called "computer-readable recording media."

[0043] EC111 is a control unit primarily used for controlling power supply-related hardware components. To streamline the control of power supply-related hardware components, the information processing device 100 has EC111, which operates in parallel with the CPU 101, in addition to the CPU 101. PD circuit 114, fan 115, and DDC 116 are connected to EC111. EC111 also includes a processor 112 and memory 113.

[0044] Processor 112 is a microprocessor with more limited processing power than CPU 101. When the power button is pressed while Processor 112 is OFF, it starts up by reading the firmware from BIOS memory 107. The firmware is executed continuously while the information processing unit 100 is ON. EC111 may be directly connected to BIOS memory 107 in order to read the firmware. Memory 113 is a volatile semiconductor memory that temporarily stores the read firmware.

[0045] The PD circuit 114 controls the power supply by the PD function. The PD circuit 114 may be included in the USB interface 110. When the information processing device 100 is the power supply side of the PD, the current output from the DDC 116 is supplied to the charging signal line of the Type-C USB port via the PD circuit 114. When the information processing device 100 is the power consumption side of the PD, the current flowing through the charging signal line of the Type-C USB port is supplied to the charging circuit 117 via the PD circuit 114, and the battery is charged.

[0046] Fan 115 is a cooling component that cools the CPU 101. Fan 115 is an air cooling device that creates airflow by rotating, and is sometimes called a cooler. When the CPU 101 is operating, it is normal for Fan 115 to be rotating. DDC116 converts 12V~18V DC to 5V DC.

[0047] The charging circuit 117 controls the supply of base power (system power) inside the information processing device 100 and the charging of the battery of the information processing device 100. The information processing device 100 may be connected to an AC adapter 118 that converts AC power from a household power supply to DC power of 12V to 18V. The charging circuit 117 charges the battery of the information processing device 100 using the DC power output of the AC adapter 118. However, the charging circuit 117 may also charge the battery using the DC power output of the PD circuit 114. The charging circuit 117 supplies the DC power output of the AC adapter 118 or the battery to various hardware components.

[0048] Here, the information processing device 100 contains hardware components with different operating voltages. Therefore, the DC / DC converter converts the DC output from the charging circuit 117 into DC with a voltage that allows the hardware components to operate. The DDC 116 supplies power to hardware components that operate on 5V DC.

[0049] As long as power is supplied to the DDC116 via the charging circuit 117, it can output 5V DC even when the CPU 101 is not operating. For this reason, the DDC116 is sometimes referred to as a constant 5V power supply. In the second embodiment, the USB interface 110, PD circuit 114, and fan 115 receive power from the DDC116. On the other hand, the CPU 101 and EC111 are supplied with power through a different path than the DDC116.

[0050] The DDC116 includes a protection circuit. The protection circuit detects abnormal currents that occur temporarily, such as overcurrents from the AC adapter 118. For overcurrent detection, the electrical circuit described in the aforementioned Patent Document 1 may be used. When the protection circuit detects an abnormal current, it switches to a state where the 5V DC output is stopped.

[0051] The 5V DC output from the DDC116 is supplied to the Type A USB port. The 5V DC output from the DDC116 is also supplied to the PD circuit 114, which then supplies power to the Type C USB port. Therefore, when the DDC116 output stops, power is no longer supplied to the PD circuit 114, and consequently, power is no longer supplied to the various USB devices connected to the USB ports included in the USB interface 110.

[0052] Once DDC116 is turned OFF, it may not automatically turn ON as long as power is being supplied to DDC116 via the charging circuit 117. The operator can reset DDC116 and return it to the ON state by temporarily disconnecting the input to DDC116 by inserting or removing the battery. Also, DDC116 is connected to EC111 via an ENABLE signal line. If DDC116 receives an ENABLE signal from EC111 while in the OFF state, it will also turn ON.

[0053] Figure 3 shows an example of hardware component connections for the DDC. The DDC116 accepts DC voltages within the range of 12V to 18V. The DDC116 supplies 5V DC to the fan 115 and the PD circuit 114. The EC111 is connected to the CPU 101 via a control signal line. The EC111 is also connected to the fan 115 and the PD114 via control signal lines. Furthermore, the EC111 is connected to the DDC116 via an ENABLE signal line.

[0054] When CPU101 starts up, it first executes the BIOS program. Following the BIOS program, CPU101 recognizes SSD106, where the OS program is stored, and executes the OS program. Normally, the execution of the BIOS program ends when the OS program starts. EC111 starts up at the same time as CPU101 and continuously executes firmware in parallel with CPU101 while CPU101 is running. CPU101 can read data from EC111's memory 113.

[0055] Fan 115 rotates using 5V DC supplied from DDC116 while the CPU 101 is operating. Fan 115 sends a pulse signal to EC111 via a control signal line with each rotation. EC111 measures the rotation speed of fan 115 per unit time by counting the pulse signals using PWM (Pulse Width Modulation). The rotation speed per unit time is, for example, rotations per minute (rpm). The measured rotation speed is stored in the memory 113 of EC111.

[0056] The PD circuit 114 controls the PD function of the USB port using 5V DC supplied from the DDC 116. The EC 111 can monitor the status of the PD circuit 114 via a control signal line between it and the PD circuit 114.

[0057] The DDC116 receives the ENABLE signal, which is a pulse signal, from the ENABLE signal line. The DDC116 performs a toggle operation in response to the ENABLE signal. When the DDC116 receives the ENABLE signal while it is OFF (stopping the 5V DC output), it switches from OFF to ON. Conversely, when the DDC116 receives the ENABLE signal while it is ON (outputting 5V DC), it switches from ON to OFF.

[0058] The EC111 can send an ENABLE signal to the DDC116 according to its firmware. However, unlike the fan 115 and the PD circuit 114, the EC111 does not have a control signal line to receive control signals from the DDC116. Therefore, the EC111 does not directly detect the ON / OFF state of the DDC116. The number of general-purpose input / output (GPIO) ports on the EC111 is finite. By not directly monitoring the state of the DDC116, the number of ports used by the EC111 is saved.

[0059] Furthermore, EC111 may detect overcurrent from the USB port via the control signal line between it and the PD circuit 114. In that case, EC111 may intentionally switch DDC116 OFF by sending an ENABLE signal to DDC116.

[0060] Figure 4 shows an example of recovery from a DDC protection operation. After the information processing unit 100 is manufactured, the operator connects the AC adapter 118 to the information processing unit 100 and turns on the information processing unit 100 for the first time. This operation may be performed at the factory where the information processing unit 100 is manufactured, or it may be performed at the destination where the information processing unit 100 is shipped.

[0061] In this case, the protection circuit of the DDC116 may activate, causing the DDC116 to be turned OFF from the start. Such protection actions during initial power-on occur due to a low probability of temporary overcurrent due to hardware design or manufacturing processes. Therefore, as described below, the BIOS program of the second embodiment implements a process to automatically restore the constant 5V power supply to the DDC116.

[0062] When the CPU 101 starts the BIOS program, it reads fan speed data from the EC111 according to the BIOS program. The fan speed is measured periodically by the EC111 using the control signal flowing through the control signal line between the EC111 and the fan 115. The data read by the CPU 101 includes the measured fan speed itself. However, if the fan speed is 0 rpm, the read result received by the CPU 101 includes a fan error indicating that an error has occurred in the fan speed.

[0063] The CPU 101 detects fan errors. The CPU 101 may also detect fan errors by comparing the read fan speed with a threshold. For example, the CPU 101 may determine that there is a fan error if the fan speed is 0 rpm, and that there is no fan error if the fan speed is greater than 0 rpm. Alternatively, the CPU 101 may determine whether or not the read result includes a fan error. In the above description, the EC111 responds to the CPU 101 with both the fan speed and the fan error, but it is also possible to have the EC11 respond to the CPU 101 with only one of the fan speed or the fan error.

[0064] Fan 115 is a typical hardware component that uses the constant 5V power supply of DDC116, and is expected to rotate while the CPU101 is operating. Therefore, if fan 115 is not rotating immediately after power-on, the information processing unit 100 estimates that there is a high probability that a failure has occurred in DDC116. In that case, it is thought that other hardware components that use the constant 5V power supply, such as the PD circuit 114, will also not function properly.

[0065] When a fan error is detected, the CPU 101, which is running the BIOS program, instructs the EC111 via the control signal line to restore the DDC116. The EC111 then sends an ENABLE signal to the DDC116 via the ENABLE signal line. This is expected to release the protection operation of the DDC116, and the DDC116 will begin outputting 5V DC. On the other hand, if no fan error is detected, the CPU 101 does not instruct the EC111 to restore the DDC116, and the EC111 does not send an ENABLE signal.

[0066] Furthermore, the CPU 101 may repeatedly perform the above process while the BIOS program is running. If a fan error is detected, the CPU 101 may instruct the EC 111 to restore the DDC 116, reset the CPU 101, and restart the BIOS program. On the other hand, in the second embodiment, since it is assumed that a failure occurs in which the protection circuit of the DDC 116 is activated due to a temporary overcurrent when the power is turned on, the CPU 101 does not need to perform the above process after the OS program starts up.

[0067] Furthermore, if a failure is anticipated during the first power-on after manufacturing, the CPU 101 may execute the above process only during the first startup after manufacturing or during a certain number of startups since manufacturing. Also, if the information processing unit 100 starts up successfully once without a fan error, the CPU 101 may not execute the above process during subsequent startups. Control flags indicating the number of startups and whether recovery is necessary may be stored in the BIOS memory 107.

[0068] Figure 5 shows an example of fan failure detection. In addition to a failure of the DDC 116, there is a low probability that the fan 115 is hardware-faulted, which could be the reason why the fan 115 does not rotate when the power is turned on. Therefore, the CPU 101 may perform a determination process to distinguish between a failure of the DDC 116 and a failure of the fan 115.

[0069] The following describes two examples of determination methods. The BIOS program may implement only one of these two determination methods, or it may implement both. If both are implemented, the CPU 101 may use only one of the determination methods, or it may use both determination methods in combination. When using both determination methods in combination, the CPU 101 may use these methods as an AND condition to determine that the fan 115 is faulty if both determination methods indicate a fan failure. Alternatively, the CPU 101 may use these methods as an OR condition to determine that the fan 115 is faulty if at least one of the determination methods indicates a fan failure.

[0070] In the first determination method, CPU 101 records that it attempted to recover DDC 116. For example, CPU 101 saves a control flag in BIOS memory 107 indicating that it attempted to recover DDC 116. CPU 101 resets itself, restarts the BIOS program, and reads the rotation speed of fan 115 again from EC111.

[0071] The CPU 101 attempts to restore the DDC 116 during the last reset and determines if a fan error indicating a fan speed of 0 rpm has been detected again. If a fan error is detected again, it is likely that fan 115 is faulty. In that case, the CPU 101 will not attempt to restore the DDC 116 any further. Therefore, from this point onward, the CPU 101 does not need to read the fan speed from EC 111, nor does it need to instruct EC 111 to restore the DDC 116.

[0072] In the second determination method, if the CPU 101 detects a fan error, it further checks the status of other devices that operate on a constant 5V power supply. In the second embodiment, USB-related devices are assumed to be other devices that operate on a constant 5V power supply. If the USB-related devices are operating normally, the fan error is likely to have been detected due to a failure of the fan 115. On the other hand, if the USB-related devices are not operating normally, the fan error is likely to have been caused by a failure of the DDC 116.

[0073] The USB-related device may be an internal hardware component connected to the EC111 via a control signal line, such as the PD circuit 114. In this case, the CPU 101 reads the status of the hardware component from the EC111. Alternatively, the USB-related device may be a USB device connected to the USB interface 110. In this case, the CPU 101 attempts to communicate with the USB device via the USB interface 110.

[0074] If a fan error is detected and other devices are not functioning correctly, the CPU 101 attempts to recover the DDC 116 as described above. On the other hand, if a fan error is detected and other devices are functioning correctly, the CPU 101 does not attempt to recover the DDC 116. Therefore, the CPU 101 does not need to instruct the EC 111 to recover the DDC 116. This allows the CPU 101 to distinguish between a DDC 116 failure and a fan 115 failure, and reduces unnecessary recovery processing for the DDC 116. Next, an example of the procedure for DDC control by the information processing device 100 will be described.

[0075] Figure 6 is a flowchart showing an example of the DDC control procedure. In step S10, EC111 measures the rotational speed of fan 115. Thereafter, EC111 continuously measures the rotational speed of fan 115. In step S11, CPU101 reads the fan rotational speed from EC111 according to the BIOS program. In step S12, CPU101 determines, based on the reading result from step S11, whether a fan error (fan rotational speed of 0 rpm) has been detected. If a fan error is detected, the process proceeds to step S13; otherwise, DDC control ends.

[0076] In step S13, the CPU 101 checks the status of USB-related devices that use a constant 5V power supply, according to the BIOS program. If there are no suitable USB-related devices whose status can be checked, the CPU 101 may skip steps S13 and S14. In step S14, the CPU 101 determines whether the USB-related devices are functioning correctly. If the USB-related devices are functioning correctly, the process proceeds to step S19. If the USB-related devices are not functioning correctly, the process proceeds to step S15.

[0077] In step S15, the CPU 101 requests EC111 to restore DDC116 according to the BIOS program. In step S16, EC111 sends an ENABLE signal to DDC116 via the ENABLE signal line. Upon receiving the ENABLE signal, DDC116 performs a toggle operation to switch whether or not to output 5V DC.

[0078] In step S17, the CPU 101 resets itself and restarts the BIOS program. The CPU 101 then reads the fan speed again from the EC111 according to the BIOS program. Note that the CPU 101 reset does not necessarily have to be performed automatically after the ENABLE signal is sent; it may be triggered by other events such as user interaction.

[0079] In step S18, the CPU 101 determines, based on the read result from step S17, whether a fan error, where the fan speed is 0 rpm, has been detected again. If a fan error is detected again, the process proceeds to step S19; otherwise, DDC control ends.

[0080] In step S19, the CPU 101 suppresses subsequent recovery processing for the DDC 116. In step S20, the CPU 101 outputs a message indicating a fan failure according to the BIOS program. The CPU 101 may display the message on the display 104 or save it as a log. After that, the CPU 101 may proceed to execute the OS program or suppress the execution of the OS program.

[0081] As explained above, in the information processing device 100 of the second embodiment, even if the protection circuit of the DDC116 is activated due to a momentary overcurrent when the power is turned on, the 5V power supply is automatically restored. This eliminates the need for personnel at the manufacturing plant or users at the shipping destination to perform recovery work such as inserting or removing batteries, improving convenience during testing and initial use.

[0082] Furthermore, even if EC111 does not have a control signal line to directly monitor the status of DDC116, CPU101 can estimate the shutdown of the constant 5V power supply. This reduces the number of GPIO ports used by EC111, simplifying the hardware design of the information processing unit 100. In addition, by referring to the rotation speed of fan 115, a typical hardware component that operates on a constant 5V power supply, CPU101 can estimate the shutdown of the constant 5V power supply in a general-purpose and efficient manner.

[0083] Furthermore, when EC111 sends an ENABLE signal to DDC116, CPU101 may re-check the fan speed after a reset. This allows CPU101 to distinguish between a DDC116 failure and a fan 115 failure. Additionally, when a fan error is detected, CPU101 may further check the status of USB-related devices that use a constant 5V power supply. This also allows CPU101 to distinguish between a DDC116 failure and a fan 115 failure. As a result, unnecessary recovery processes are suppressed. [Explanation of Symbols]

[0084] 10 Information Processing Devices 11 Converters 12 Fans 13 processors 14 Data 15 Enable signal

Claims

1. A converter that converts a first DC having a first voltage to a second DC having a second voltage different from the first voltage, wherein the converter stops the output of the second DC in response to the detection of an abnormal current and restarts the output in response to the reception of an enable signal, The fan that rotates using the second DC power, A processor that acquires data on the rotational speed per unit time of the fan and controls the transmission of the enable signal to the converter in response to the detection of a fan error indicating that the rotational speed is below a threshold, An information processing device having

2. The fan and the processor are connected via control signal lines, and the system further includes another processor that measures the rotational speed. The processor obtains the rotation speed data from the other processor and, in response to the detection of the fan error, requests the other processor to transmit the enable signal. The information processing apparatus according to claim 1.

3. The processor, in accordance with the BIOS (Basic Input Output System) program executed when the information processing device is started, acquires the rotational speed data, detects the fan error, and controls the enable signal. The information processing apparatus according to claim 1.

4. After the enable signal is transmitted, the processor reacquires the rotation speed data to determine if the fan error has been resolved, and if the fan error has not been resolved, it suppresses further transmission of the enable signal to the converter. The information processing apparatus according to claim 1.

5. The processor, in response to the detection of the fan error, determines the state of the second DC-using device other than the fan, and if the device is normal, suppresses the transmission of the enable signal to the converter. The information processing apparatus according to claim 1.

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