DSP firmware loading circuit and method, optical module

Abstract

The present invention relates to the field of optical communication technology, and discloses a DSP firmware loading circuit and method, and an optical module. The DSP firmware loading method comprises: after the device is powered on, the MCU first controls the DSP unit to enter a non-working mode through a GPIO interface and then initializes; the MCU controls the DSP unit to enter a working mode through the GPIO interface; the DSP unit sends a loading control instruction to the MCU through the SPI interface; after receiving the loading control instruction, the MCU sends the DSP firmware to the DSP unit through the SPI interface to load the DSP firmware. In the embodiment of the present invention, the DSP firmware is stored in the memory of the MCU, and the MCU can directly control the DSP unit to load the DSP firmware, which not only reduces the use of external EEPROM chips and peripheral circuits, reduces the implementation cost, but also greatly saves assembly space, is conducive to product heat dissipation, and ensures the stability of product performance.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to a DSP firmware loading circuit and method, and an optical module. Background Art

[0002] PAM4 is a type of PAM (Pulse Amplitude Modulation) modulation technology. PAM signal is a popular signal transmission technology after NRZ (Non-Return-to-Zero), and is also a representative of multi-order modulation technology. It can effectively improve bandwidth utilization efficiency and has been widely used in the field of high-speed signal interconnection. NRZ signal uses high and low signal levels to represent 1 and 0 of digital logic signals, and can transmit 1 bit of logic information per clock cycle. PAM4 signal uses 4 different signal levels for signal transmission, and can transmit 2 bits of logic information per clock cycle, namely 00, 01, 10, 11. Therefore, under the same baud rate conditions, the bit rate of PAM4 signal is twice that of NRZ signal, which doubles the transmission efficiency and effectively reduces costs.

[0003] The existing PAM4 optical modules mainly use the following two methods to load DSP firmware:

[0004] Method 1: Use an external EEPROM chip to store the DSP firmware program. Before mounting the EEPROM chip, first use a burner to burn the DSP firmware into the EEPROM chip. Each time the MCU is powered on, it will control the DSP to load the EEPROM firmware.

[0005] Method 2: Use an external EEPROM chip to store the DSP firmware program. After the module is made, burn the MCU program first, and then use the control command to burn the DSP firmware into the EEPROM chip. Each subsequent time the MCU is powered on, it will control the DSP to load the EEPROM firmware.

[0006] However, both loading methods have the following defects:

[0007] (1) Regardless of the method, an external EEPROM chip is required, and peripheral circuits need to be added, which is not only costly but also occupies a large assembly space and is not conducive to PCB layout and heat dissipation.

[0008] Especially for SFP56 PAM4 optical modules, the board space is very limited and basically cannot accommodate external EEPROM chips, which will greatly affect the stability of the optical module.

[0009] (2) To complete the firmware loading, a burner or professional programmer needs to be used to burn the program twice, once for the DSP and once for the MCU. Not only is the operation complicated, but the burner or professional programmer is expensive and difficult to operate. If the operation is not standardized, it may even damage the optical module. Summary of the invention

[0010] The purpose of the present invention is to provide a DSP firmware loading circuit and method, and an optical module to solve the problems of high cost, complex operation and impact on optical module performance in the prior art.

[0011] To achieve this object, the present invention adopts the following technical solutions:

[0012] A DSP firmware loading circuit comprises an MCU and a DSP unit;

[0013] The MCU includes a memory; the memory includes a DSP firmware storage area for storing a DSP firmware program, an MCU firmware storage area for storing an MCU firmware, and a Bootloader program storage area for storing a Bootloader control program;

[0014] The MCU and the DSP unit both include a GPIO interface, an SMI interface and an SPI interface; the MCU is connected to the DSP via the GPIO interface, the SMI interface and the SPI interface respectively;

[0015] When the GPIO interface outputs a low level, the SPI interface of the DSP unit is in a high-impedance output state; when the GPIO interface outputs a high level, the MCU loads the DSP firmware to the DSP unit through the SPI interface.

[0016] Optionally, the SMI interface of the MCU and the SMI interface of the DSP unit are connected via a two-wire power conversion chip.

[0017] Optionally, the storage space of the memory is 256K byte; the DSP firmware storage area is 128K byte, the MCU firmware storage area is 127K byte, and the Bootloader program storage area is 1K byte.

[0018] Optionally, the SPI interface includes: a master device data input interface, a master device data output interface, a clock interface and a chip select interface.

[0019] A DSP firmware loading method, applied to the DSP firmware loading circuit as described above, comprises the steps of:

[0020] After the device is powered on, the MCU first controls the DSP unit to enter a non-working mode through the GPIO interface and then initializes it;

[0021] After completing the initialization, the MCU controls the DSP unit to enter the working mode through the GPIO interface;

[0022] After entering the working mode, the DSP unit sends a loading control instruction to the MCU through the SPI interface;

[0023] After receiving the loading control instruction, the MCU sends the stored DSP firmware to the DSP unit through the SPI interface to implement DSP firmware loading.

[0024] Optionally, the method further includes: after the DSP firmware is loaded, the MCU stops SPI communication with the DSP unit and initializes the configuration of the DSP unit through an SMI interface.

[0025] Optionally, the method further includes: upon receiving a DSP firmware upgrade instruction, the MCU updates the DSP firmware in the storage area through a Bootloader control program.

[0026] Optionally, the method further includes: when receiving a DSP firmware upgrade instruction and an MCU firmware upgrade instruction at home, the MCU simultaneously updates the DSP firmware and the MCU firmware in the storage area through a Bootloader control program.

[0027] An optical module comprises any one of the above-mentioned DSP firmware loading circuits.

[0028] A storage medium stores a plurality of instructions, wherein the instructions are suitable for a processor to load to execute the steps in any one of the above DSP firmware loading methods.

[0029] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0030] Different from the method of using an external EEPROM chip, the embodiment of the present invention stores the DSP firmware in the memory of the MCU. The MCU can directly control the DSP unit to load the DSP firmware, which not only reduces the use of external EEPROM chips and peripheral circuits and reduces the implementation cost, but also greatly saves assembly space, facilitates product heat dissipation, and ensures the stability of product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A schematic diagram of a DSP firmware loading circuit provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the distribution of the MCU internal program in the flash provided by an embodiment of the present invention;

[0034] Figure 3 This is a flow chart of a DSP firmware loading method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the embodiments of the present invention.

[0036] The terms "including" and "having" and any variations thereof in the specification and claims of the embodiments of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or apparatus.

[0037] See also Figure 1 The embodiment of the present invention provides a DSP firmware loading circuit, including an MCU (Microcontroller Unit) and a DSP (digital signal processing) unit.

[0038] Both the MCU and the DSP unit include: a GPIO (general-purpose input / output) interface, an SMI interface (Serial Management Interface), and an SPI interface (serial peripheral interface).

[0039] The GPIO interface can be configured by software. In this embodiment, the GPIO interface is configured as a control signal interface.

[0040] SMI interface, including MDC interface and MDIO interface. MDIO interface is a DSP management interface, used to read / write DSP registers to control DSP behavior or obtain DSP status. MDC interface provides clock for MDIO.

[0041] The SPI interface uses 4-wire communication, including: MISO (master data input) interface, MOSI (master data output) interface, SCLK (clock) interface, and CS (chip select) interface.

[0042] The MCU is connected to the DSP unit through the GPIO interface, SMI interface and SPI interface respectively. The DSP is the Master end, and the MCU is the Slave end. The MCU controls the DSP to work through the GPIO interface.

[0043] MCU, including memory; such as Figure 2 As shown, the memory includes: a DSP firmware storage area for storing a DSP firmware program, an MCU firmware storage area for storing an MCU firmware, and a Bootloader program storage area for storing a Bootloader control program.

[0044] For example, when the storage space of the selected memory is 256K bytes, it can be divided as follows: DSP firmware storage area is 128K bytes, MCU firmware storage area is 127K bytes, and Bootloader program storage area is 1K bytes. Of course, the size of each storage interval can be flexibly adjusted according to different memory types and different usage requirements, and the present invention does not limit it.

[0045] In the DSP firmware loading circuit of this embodiment, when the GPIO interface outputs a low level, the SPI interface of the DSP unit is in a high-impedance output state, and the MCU and the DSP unit cannot perform SPI communication; when the GPIO interface outputs a high level, the SPI interface of the DSP unit is in a low-impedance output state, and the MCU and the DSP can perform normal SPI communication. The MCU can send the DSP firmware stored internally to the DSP unit through the SPI interface to realize the loading of the DSP firmware.

[0046] In addition, since the typical operating voltage of the DSP unit is 1.8V and the MCU is 3.3V, in this embodiment, the SPI interface of the MCU and the SPI interface of the DSP unit are connected through a two-wire power conversion chip to achieve voltage conversion processing to ensure the normal operation of both the DSP unit and the MCU.

[0047] This embodiment also provides a DSP firmware loading method, which is applied to the above-mentioned DSP firmware loading circuit, and specifically includes:

[0048] Step 101: After the device is powered on, the MCU first controls the DSP unit to enter a non-working mode through the GPIO interface, and then performs initialization.

[0049] In this step, the MCU controls the GPIO interface to output a low level, so that the DSP unit enters a non-working mode. At this time, the four SPI lines of the DSP are in a high-impedance output state, so that there is no communication between the DSP unit and the MCU.

[0050] Step 102: After completing the initialization, the MCU controls the DSP unit to enter the working mode through the GPIO interface.

[0051] The MCU controls the GPIO interface to output a high level, which allows the DSP unit to enter the working mode.

[0052] Step 103: After entering the working mode, the DSP unit sends a loading control instruction to the MCU via the SPI interface.

[0053] Step 104: After receiving the loading control instruction, the MCU sends the stored DSP firmware to the DSP unit through the SPI interface to implement DSP firmware loading.

[0054] Specifically, after receiving the loading control instruction, the MCU will send the DSP firmware program to the DSP unit through the SPI communication through the SPI interrupt service program; after the sending is completed, the MCU closes the interrupt service program and stops the SPI communication.

[0055] Step 105: The MCU initializes and configures the DSP unit through the SMI interface so that all functions of the DSP unit work normally.

[0056] After that, the MCU performs some other routine initialization operations to put the entire device into normal working mode.

[0057] Different from the method of using an external EEPROM chip, this embodiment stores the DSP firmware in the memory of the MCU itself, and the DSP firmware loading can be realized through simple control, which not only reduces the use of external EEPROM chips and peripheral circuits, reduces the implementation cost, but also greatly saves assembly space and is beneficial to the heat dissipation of the equipment.

[0058] After the Bootloader control program is burned into the MCU for the first time, it is fixed in the falsh and generally will not be changed. Based on this, when the MCU firmware program needs to be upgraded, the Bootloader control program can update the MCU firmware in the falsh according to the MCU firmware upgrade control instructions.

[0059] Similarly, when the DSP firmware needs to be upgraded, the DSP firmware in the falsh can also be updated through the Bootloader control program according to the DSP firmware upgrade control instruction.

[0060] Of course, if both the DSP firmware and the MCU firmware need to be upgraded, the Bootloader control program can be used to update the DSP firmware and the MCU firmware in the falsh at the same time.

[0061] In the traditional implementation method of using an external EEPROM chip, if the DSP firmware needs to be upgraded later, the device housing needs to be disassembled first, and then the SPI interface of the EEPROM chip needs to be connected to the burner for burning, so that the DSP firmware in the EEPROM chip can be upgraded. The entire upgrade operation is very troublesome. Compared with the traditional method, the method of implementing DSP firmware upgrade through the Bootloader control program in this embodiment is obviously simpler and faster, and solves the subsequent production and maintenance problems of the device.

[0062] This embodiment also provides an optical module, which includes the above-mentioned DSP firmware loading circuit. Through the DSP firmware loading circuit, the optical module can realize simple and reliable DSP firmware loading, and ensure performance stability, greatly improving market competitiveness.

[0063] Those skilled in the art will appreciate that all or part of the steps in the above DSP firmware loading method may be completed by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0064] To this end, an embodiment of the present invention further provides a storage medium, in which a plurality of instructions are stored. The instructions can be loaded by a processor to execute the steps in the low power consumption control method provided by the embodiment of the present invention.

[0065] The storage medium may include: a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0066] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A DSP firmware loading circuit, characterized in that: Including MCU and DSP units; The MCU includes a memory; the memory includes a DSP firmware storage area for storing a DSP firmware program, an MCU firmware storage area for storing an MCU firmware, and a Bootloader program storage area for storing a Bootloader control program; The MCU and the DSP unit both include a GPIO interface, an SMI interface and an SPI interface; the MCU is connected to the DSP via the GPIO interface, the SMI interface and the SPI interface respectively; When the GPIO interface outputs a low level, the SPI interface of the DSP unit is in a high-impedance output state; when the GPIO interface outputs a high level, the MCU loads the DSP firmware to the DSP unit through the SPI interface.

2. The DSP firmware loading circuit according to claim 1, characterized in that: The SMI interface of the MCU and the SMI interface of the DSP unit are connected via a two-wire power conversion chip.

3. The DSP firmware loading circuit according to claim 1, characterized in that: The storage space of the memory is 256K bytes; the DSP firmware storage area is 128K bytes, the MCU firmware storage area is 127K bytes, and the Bootloader program storage area is 1K bytes.

4. The DSP firmware loading circuit according to claim 1, characterized in that: The SPI interface includes: a master device data input interface, a master device data output interface, a clock interface and a chip select interface.

5. A DSP firmware loading method, characterized in that: The DSP firmware loading circuit according to claim 1 comprises the steps of: After the device is powered on, the MCU first controls the DSP unit to enter a non-working mode through the GPIO interface and then initializes it; After completing the initialization, the MCU controls the DSP unit to enter the working mode through the GPIO interface; After entering the working mode, the DSP unit sends a loading control instruction to the MCU through the SPI interface; After receiving the loading control instruction, the MCU sends the stored DSP firmware to the DSP unit through the SPI interface to implement DSP firmware loading.

6. The DSP firmware loading method according to claim 5, characterized in that: Also includes: After the DSP firmware is loaded, the MCU stops the SPI communication with the DSP unit and initializes the configuration of the DSP unit through the SMI interface.

7. The DSP firmware loading method according to claim 5, characterized in that: Also includes: When receiving the DSP firmware upgrade instruction, the MCU updates the DSP firmware in the storage area through the Bootloader control program.

8. The DSP firmware loading method according to claim 5, characterized in that: Also includes: When receiving the DSP firmware upgrade instruction and the MCU firmware upgrade instruction at home, the MCU simultaneously updates the DSP firmware and the MCU firmware in the storage area through the Bootloader control program.

9. An optical module, characterized in that: The optical module comprises the DSP firmware loading circuit as described in any one of claims 1 to 4.

10. A storage medium, characterized in that: The storage medium stores a plurality of instructions, and the instructions are suitable for loading by a processor to execute the steps in the DSP firmware loading method according to any one of claims 5 to 8.

Images