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STM32
hardware setup
ST-LINK v2
SWCLK (clock) ; SWDIO (data input & output) ; power supply (for the micro chip) you can find the corresponding pins on stm32 chip (SWCLK SWDIO)
SWCLK pull low externally (link to GND); SWDIO pull high
for JTAG, pins are same (Punctual Atom STM32F1 board)
you can also find SWDIO is pulled up while SWCLK is pulled down.
Degub protoptype (JTAG / SWD)
https://blog.csdn.net/LEON1741/article/details/72846434
JTAG is the test protocol inside the chip. The standard JTAG interface is 4 wires: TMS, TCK, TDI, TDO, which are the mode selection, clock, data input and data output lines respectively. The definition of the relevant JTAG pins is:
TMS: Test mode selection, TMS is used to set the JTAG interface in a specific test mode;
TCK: Test clock input;
TDI: Test data input, the data is input to the JTAG interface through the TDI pin;
TDO: Test data output, the data is output from the JTAG interface through the TDO pin;
SWD, Serial Wire Debug, fewer pins (4), more stable under big data.
You can see that SWD and JTAG share the same port for the punctual atom board above.
SWD uses fewer interfaces than JTAG, only four wires SWDIO, SWCLK, VCC, GND (four excuses on stm32f103-minimum)
Emulator
jlink
Based on JTAG simulation, the USB port is used for the computer, and the JTAG port is still used for the board
ST - link
It is specially designed for ST company chips, which can be programmed, simulated, and downloaded. st-link v2 is common to JTAG and SWD, and you can choose it at Keil.
Burn
- openocd
See how to install and program openocd in nuttx
openocd -f interface/stlink-v2.cfg -f target/stm32f1x.cfg -c init -c "reset halt" -c "flash write_image erase nuttx.bin 0x08000000"
openocd can also be used to connect with the chip to provide a local port for debugging.
openocd -f interface/stlink-v2.cfg -f target/stm32f1x.cfg
openocd profile /usr/local/share/openocd/scriptsunder. interfaceCorresponds to the debugger hardware (stlink-v2, …) targetCorresponds to the board
- stlink
Use stlink driver to burn. At this point BOOT0the BOOT1pin is pulled low, start from FLASH.
- Serial port programming program
In STM32CubeProgrammerthe
Select the serial port mode, then select the startup mode, and then System Memoryburn the program after connecting with the serial port.
- BOOT pin setting during programming.
| BOOT0 | BOOT1 | Start method |
|---|---|---|
| 0 | Irrelevant | User Flash memory startup (User Flash memory) |
| 1 | 0 | Boot from system memory (System memory) |
| 1 | 1 | Boot from Embedded SRAM (Embedded SRAM) |
- User Flag memory
Normal working mode
- System Memory
The system memory is a specific area inside the chip. When ST leaves the factory, a section of bootloader (ROM) is preset inside. With the help of bootloader, download the program to the flash through the serial port.
- Embedded SRAM
This mode is used to debug code (do not need to erase all from)
2020.5.30 The reason why stlink-v2 cannot connect to the chip through openocd has been unclear at night. Later, it was discovered that the Boot wiring was incorrect, which caused the driver to fail to detect the chip.
If booting from the main flash memory, access from address 0x0800 0000, which is to program the specified address through openocd.
The built-in SRAM is at 0x2000 0000
Debug
Currently debugging can be done with openocd. Pay attention to modify the size of the programming file area in the startup file.
arm-none-eabi-gdb nuttx # program name
# gdb interface
target remote localhost:3333 # connect to the localhost port provided by openocd
monitor reset # reset chip
monitor halt # halt the program
load nuttx # load binary file
monitor It is a command sent to the chip locally and remotely.
Custom Board
Here is a record of some boards you have seen and HALprecautions when using them.
STM32F407G-DISC1
STM32 official board. The interesting part of this board is that it integrates a stlink-v2 debugger, so you don't need to buy another one yourself. CN3Control the debugger selection. When jumping, select the debugger integrated on the board. Otherwise, you can use your own debugger to connect directly to the GPIO pins.
STM32F103ZET6 (punctual atomic warship board)
Die configuration:
RCCSelect the insideHSE,LSE.sysInsideDebugchooseSerial Wire. (Otherwise ST-Link cannot be used for debugging)- Checking
NVIC->Code Generation->System Tick Timerwhether to generate an interrupt response functionIRQand callHALhandler (HAL_Handler).
Remember to plug in the power connector on the left side of the board.
communication
UART
Asynchronous transceiver serial communication <--> synchronous mode (USART)
Standards: RS232. RS449
COM is the asynchronous serial communication port RS232 on the PC
Keeping the low level at the beginning is to ensure that the data line is normal. The low level indicates the start of data transmission. After the UART accepts, it sets a flag to indicate that the data is available (checked in the interrupt processing function), and generates a processor interrupt. Use UARTwill be a time Hard Ware Control Flowoption is corresponding to RTSthe CTSpin for transmission of auxiliary data. Correspondingly, read the register in the HAL library and compare it with the flag to determine whether the next transmission is to be made. (Function UART_WaitOnFlagUntilTimeout) in minicomthe same need to configure the Hardware control flowoptions.
CTS <---> RTS
RTS <---> CTS
CAN
The CAN protocol communicates through the following five data frames.
chip Reg
CLOCK
RCC (Reset Clock Control)
AHB (Advanced High performance Bus)
GPIO
MODER (mode register)
OTYPER (output type register)
HERE
Program
stmf4xx.h has defines about registers
RCC -> AHBENR |= RCC_AHBENR_GPIOCEN ; // or (1 << 19) specify the bits
// set zero
GPIOC -> OTYPER &= ~(...)
ASSEMBLY CODE
eg. inline assembly code
int x = 1, y = 2 ;
int res = 0;
__asm ("ADD %[result], %[input_x], %[input_y]"
: [result] "=r" (res)
: [input_x] "r" (x), [input_j] "r" (y)
)
The format is
Stem Type> STM32 Peripheral Support to determine the peripheral used
> System Type> Alternate Pin Mapping to determine the remapping relationship
PWM
Configure pwm Timer and output channel in stm32f103-minimum config under boards. Confirm in stm32f103-minimum.h that the defined channels and timers are consistent with those in config
> System Type> Timer Configuration Configure timer usage mode and output channel