CN110908948A

CN110908948A - High-speed DO and PWM output integrated circuit board based on MCU + FPGA

Info

Publication number: CN110908948A
Application number: CN201911304033.4A
Authority: CN
Inventors: 池洪伟; 赵静; 胡江华; 陈丽平; 谭新新; 王彦明; 张向宇; 李雄铭; 刘俊丽
Original assignee: Radium Intelligence Science And Technology Co Ltd Is Irrigated In Hangzhou
Current assignee: Radium Intelligence Science And Technology Co Ltd Is Irrigated In Hangzhou
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-03-24

Abstract

The invention discloses a high-speed DO and PWM output board card based on MCU + FPGA, the FPGA is used as a function device expanded outside the MCU, the SPI and IO ports of the MCU are adopted to carry out real-time data communication with the FPGA, the FPGA can carry out corresponding setting according to the command of the MCU, an output mode is selected according to the setting condition, when the DO is output, the FPGA directly carries out output operation on I/O port information, and the delay is only 10 ns; when the PWM output mode is selected, the FPGA directly outputs a corresponding PWM signal. The invention has the beneficial effects that: the functions of the MCU and the FPGA are fully exerted, on the basis of the original MCU scheme, only one low-cost FPGA chip is needed to be added, high-precision DO and PWM output can be achieved, the cost is low, the development period is short, the performance is high, and the reliability is high.

Description

High-speed DO and PWM output integrated circuit board based on MCU + FPGA

Technical Field

The invention relates to the field of automobile detection, in particular to a high-speed DO and PWM output board card based on MCU + FPGA, which is applicable to a detection system of electronic components such as an automobile controller.

Background

When electronic components such as an automobile controller and the like are detected, switching value output signals and PWM signals are often needed, and requirements on instantaneity, precision and the like are extremely high. Most of domestic DO board cards are realized by adopting the MCU, although DO output has better real-time performance, PWM output capacity is extremely weak, and even some DO board cards DO not have the function. Some foreign high-performance board cards are realized by adopting an FPGA scheme, but the price is extremely high. If all functions are realized by adopting the FPGA, the development difficulty and the development period of the FPGA are multiplied.

In order to overcome the above-mentioned shortcomings, the conventional microprocessor can not meet the PWM output requirement, especially when the number of output channels is large. The FPGA scheme can be adopted, but the development period is long, and the cost is high. The invention adopts the micro control unit MCU and the FPGA as a control system of the board card, and the functions of communication, calculation, storage and the like are put on the micro control unit MCU for processing, the output of DO is also directly controlled by the micro control unit MCU, the FPGA only plays a role of transmission, and the PWM function and the output form are put on the FPGA, thereby realizing the high-precision PWM output.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a high-speed DO and PWM output board card based on an MCU + FPGA.

The purpose of the invention is realized by the following technical scheme:

a high-speed DO and PWM output board card based on MCU + FPGA comprises a micro control unit MCU and an FPGA unit; the MCU is connected with the FPGA unit through 8 IO ports and a serial peripheral interface SPI; the FPGA unit is connected with the switching value output unit DO;

in a DO output state, the MCU sends a DO signal to pass through the FPGA unit, the FPGA unit does not process the signal, and the DO signal sent by the MCU is directly transmitted to the DO output unit;

in a PWM output state, the MCU sends output configuration information and PWM output information through the SPI, the FPGA unit generates corresponding PWM output signals according to the received output configuration information and the PWM output information and transmits the PWM output signals to the DO;

the micro control unit MCU is connected with the host computer in a real-time communication manner.

Furthermore, the micro control unit MCU is in real-time communication connection with the host through the EtherCAT communication unit.

Further, the FPGA unit is connected to the switching value output unit DO through 8 pairs of IO ports.

Further, the configuration information and the PWM output information include frequency, duty ratio and phase information.

The invention has the beneficial effects that: the functions of the MCU and the FPGA are fully exerted, on the basis of the original MCU scheme, only one low-cost FPGA chip is needed to be added, high-precision DO and PWM output can be achieved, the cost is low, the development period is short, the performance is high, and the reliability is high.

Drawings

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

FIG. 1 is an electrical schematic of the present invention;

fig. 2 is a top level schematic diagram of an FPGA cell.

Wherein: POWER represents the POWER supply unit of whole system, and MCU is little the control unit, and FPGA is the FPGA unit, and EtherCAT is EtherCAT communication unit, and DO is switching value output unit, and SPI is SPI communication unit.

Detailed Description

Fig. 1 is an electrical schematic diagram of the high-speed DO and PWM output board card of the present invention, which includes a micro control unit MCU, an EtherCAT communication unit, an FPGA unit, and a switching value output unit DO.

The EtherCAT communication unit is connected with the MCU to realize real-time communication with the host; the MCU is connected with the FPGA unit through 8 IO ports and one SPI; the FPGA unit is connected with the switching value output unit through 8 pairs (16) of IO ports.

The MCU comprises a micro control unit MCU, a random access Memory (MCU), a Random Access Memory (RAM), a Read Only Memory (ROM) and a timer, and is characterized in that the MCU comprises multiple communication interfaces, the RAM, the ROM and the timer, and realizes real-time communication of a core unit, data calculation and a storage template self-checking function, the MCU is in real-time communication with a host through an EtherCAT communication unit, main data comprises output configuration information, frequency and duty ratio of a Data Output (DO) value and a Pulse Width Modulation (PWM) signal, the MCU has a storage function, relevant configuration information cannot be lost after power failure, normal work can be realized when a board card is electrified, the MCU also has.

The FPGA unit is the core of the design, the FPGA is used as a function device of the external extension of the MCU, the FPGA and the MCU are connected in 2 modes, one mode is 8-channel IO port connection, and the other mode is an SPI port. The SPI is mainly used for transmitting configuration information, the requirement of the configuration information on delay is low, the SPI completely meets the performance requirement, when the SPI is configured to be PWM output, the FPGA can generate PWM signals according to specific configuration information, the PWM signals are output through 8 IO ports (16), when the SPI is configured to be DO output, an output port is directly controlled by 8 input IO ports, and the delay is only 10 ns.

The switching value output unit can determine whether push-pull output, source type output, drain type output or high-resistance output (mainly determined by a pair of IO signals which have dead zone control function to ensure that the upper and lower tubes are not conducted simultaneously) according to the output signal of the FPGA. The switching value output unit has an overcurrent protection function and a short-circuit protection function, and therefore the module cannot be damaged when wiring is wrong or a signal is sent into the module to cause a problem.

Fig. 2 is a schematic diagram of the top level of an FPGA cell (only 1 channel is taken as an example, and actually 8 channels). The system mainly comprises 2 modules, one unit is an SPI communication module, and the other module is a PWM and DO output module. The SPI communication module can carry out corresponding communication and extract the frequency, duty ratio, phase and corresponding configuration information of each channel. The PWM and DO output module determines the output type and mode according to the configuration information, if the output is PWM output, the module generates corresponding PWM signals for driving DO _ H and DO _ L, the pair of signals are provided with dead zone control, and dead zone time can be modified according to the configuration information. If the output is DO, DO _ H and DO _ L are directly controlled by the input signal DI (the dead zone and the output mode are still determined by the configuration information).

The described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of the present invention.

Claims

1. A high-speed DO and PWM output board card based on MCU + FPGA is characterized by comprising a micro control unit MCU and an FPGA unit; the MCU is connected with the FPGA unit through 8 IO ports and a serial peripheral interface SPI; the FPGA unit is connected with the switching value output unit DO;

2. The MCU + FPGA-based high-speed DO and PWM output board card of claim 1, wherein the MCU is in real-time communication connection with a host through an EtherCAT communication unit.

3. The MCU + FPGA-based high-speed DO and PWM output board card as claimed in claim 1, wherein the FPGA unit is connected with the switching value output unit DO through 8 pairs of IO ports.

4. The MCU + FPGA based high-speed DO and PWM output board of claim 1, wherein the configuration information and PWM output information includes frequency, duty cycle and phase information.