Table of contents
1. The purpose of the experiment
Second, the register realizes lighting
4. Observe the output waveform of the GPIO port
3. HAL library lights up LED running lights
(3) Configure the debugging interface
4. USART serial communication to send Hello world
1. USART function introduction
6. Observe the output waveform
1. The purpose of the experiment
Install stm32CubeMX, cooperate with Keil, and try to use the register address method (assembly or C, no limit) and HAL library to complete the following tasks:
1. Redo the last LED running light job, that is, use the GPIO port to complete the periodic flashing of 3 LED traffic lights.
2. Complete a STM32 USART serial communication program (the query method is sufficient, and the interrupt method is not required for the time being), requiring:
(1) Set the baud rate to 115200, 1 stop bit, no parity bit;
(2) The STM32 system continuously sends "hello windows!" to the host computer (win10). win10 uses the "serial port assistant" tool to receive.
In the absence of an oscilloscope, Keil's software simulation logic analyzer function can be used to observe the timing waveform of the pin, which is more convenient for dynamic tracking and debugging and locating code failure points. Please use this function to observe the output waveforms of the 3 GPIO ports in question 1 and the serial output waveforms in question 2, and analyze whether the timing status is correct or not, and what is the actual high-low level transition period (LED blinking period).
Second, the register realizes lighting
1. Project creation
Basically the same as the last experiment
Note that when this interface appears
edit
Just close this window
The selection of the chip needs to be replaced with STM32F103C8
2. Write code
Then add the .c program and write the following code
//--------------APB2???????------------------------
#define RCC_AP2ENR *((unsigned volatile int*)0x40021018)
//----------------GPIOA????? ------------------------
#define GPIOA_CRL *((unsigned volatile int*)0x40010800)
#define GPIOA_ORD *((unsigned volatile int*)0x4001080C)
//----------------GPIOB????? ------------------------
#define GPIOB_CRH *((unsigned volatile int*)0x40010C04)
#define GPIOB_ORD *((unsigned volatile int*)0x40010C0C)
//----------------GPIOC????? ------------------------
#define GPIOC_CRH *((unsigned volatile int*)0x40011004)
#define GPIOC_ORD *((unsigned volatile int*)0x4001100C)
//-------------------???????-----------------------
void Delay_wxc( volatile unsigned int t)
{
unsigned int i;
while(t--)
for (i=0;i<800;i++);
}
//------------------------???--------------------------
int main()
{
int j=100;
RCC_AP2ENR|=1<<2; //APB2-GPIOA??????
RCC_AP2ENR|=1<<3; //APB2-GPIOB??????
RCC_AP2ENR|=1<<4; //APB2-GPIOC??????
//????????? RCC_APB2ENR|=1<<3|1<<4;
GPIOA_CRL&=0x0FFFFFFF; //??? ??
GPIOA_CRL|=0x20000000; //PA7????
GPIOA_ORD|=1<<7; //???????
GPIOB_CRH&=0xFFFFFF0F; //??? ??
GPIOB_CRH|=0x00000020; //PB9????
GPIOB_ORD|=1<<9; //???????
GPIOC_CRH&=0x0FFFFFFF; //??? ??
GPIOC_CRH|=0x30000000; //PC15????
GPIOC_ORD|=0x1<<15; //???????
while(j)
{
GPIOA_ORD=0x0<<0; //PB0???
Delay_wxc(1000000);
GPIOA_ORD=0x1<<0; //PB0???
Delay_wxc(1000000);
GPIOB_ORD=0x0<<9; //PB9???
Delay_wxc(1000000);
GPIOB_ORD=0x1<<9; //PB9???
Delay_wxc(1000000);
GPIOC_ORD=0x0<<15; //PC15???
Delay_wxc(1000000);
GPIOC_ORD=0x1<<15; //PC15???
Delay_wxc(1000000);
}
}
Note that in the Options switch to the Output interface
Check Generate hex file
Add driver files
[
edit
Copy it to the project directory
3. Burn and compile
Open mcuisp and upload the hex file generated in the project
Click to start programming
edit
4. Observe the output waveform of the GPIO port
The light of the pin is low level, the light of high level is off, and the high-low level conversion cycle (LED flashing cycle) is about 1.12s.
3. HAL library lights up LED running lights
1. Install the HAL library
After installing SMT32CubeMX, you also need to install a firmware library, because the chip I use is the STM32F103 series, so I choose the STM32F1 version for installation. After installation, the environment is set up.
2. Create a project
Click New Project to create a project
Select this, then select the chip and click Start Project
3. Configuration work
(1) Clock configuration
First select RCC in the system core, then set HSE (external high-speed clock) to Crystal/Ceramic Resonator (crystal/ceramic resonator)
Then, click Clock Configuration to enter the system clock tree settings. Since the highest clock of STM32 is 72MHz, you can set it as shown in the figure.
(2) GPIO configuration
First select GPIO in the system core, and then select the pins. The GPIO Output pins I selected are A1, B1, and C15. The default output mode is push-pull output, so no changes are required.
(3) Configure the debugging interface
Select SYS in System Core, select Debug as required, and select Serial Wire to complete the configuration.
Next, observe the clock architecture. The clock of the APB2 bus is controlled by hse. At the same time, the right side of PLLCLK must be selected on this interface.
Set hse there to Crystal/Ceramic Resonator
A total of three output s are selected, which are PA4, PB9, and PC15:
(4) Generate project
After the final completion, select the folder and project name, click GENERATE CODE to generate the project, and the generated program is in the project. Select to generate the initialization .c/.h file, then click generate code, select open project, and then go to KEIL5
3 Add code
Open the main.c file and slip down the part of the main function:
HAL_GPIO_WritePin(GPIOA,GPIO_PIN_1,GPIO_PIN_RESET); HAL_Delay(500); HAL_GPIO_WritePin(GPIOA,GPIO_PIN_1,GPIO_PIN_SET); HAL_Delay(500); HAL_GPIO_WritePin(GPIOB,GPIO_PIN_1,GPIO_PIN_RESET); HAL_Delay(500); HAL_GPIO_WritePin(GPIOB,GPIO_PIN_1,GPIO_PIN_SET); HAL_Delay(500); HAL_GPIO_WritePin(GPIOC,GPIO_PIN_15,GPIO_PIN_RESET); HAL_Delay(500); HAL_GPIO_WritePin(GPIOC,GPIO_PIN_15,GPIO_PIN_SET); HAL_Delay(500);
4. USART serial communication to send Hello world
1. USART function introduction
USART (Universal Synchronous/Asynchronous Receiver/Transmitter) is a full-duplex universal synchronous and asynchronous serial transceiver module. This interface is a highly flexible serial communication device. The USART transceiver module is generally divided into three parts: clock generator, data transmitter and receiver. Control registers are shared by all modules.
2. Code implementation
Create a project with keli and add assembly code
Note that there is no need to check here because of assembly language.
Add assembly file (.s)
add code
;RCC register address map
RCC_BASE EQU 0x40021000
RCC_CR EQU (RCC_BASE + 0x00)
RCC_CFGR EQU (RCC_BASE + 0x04)
RCC_CIR EQU (RCC_BASE + 0x08)
RCC_APB2RSTR EQU (RCC_BASE + 0x0C)
RCC_APB1RSTR EQU (RCC_BASE + 0x10)
RCC_AHBENR EQU (RCC_BASE + 0x14)
RCC_APB2ENR EQU (RCC_BASE + 0x18)
RCC_APB1ENR EQU (RCC_BASE + 0x1C)
RCC_BDCR EQU (RCC_BASE + 0x20)
RCC_CSR EQU (RCC_BASE + 0x24)
;AFIO register address map
AFIO_BASE EQU 0x40010000
AFIO_EVCR EQU (AFIO_BASE + 0x00)
AFIO_MAPR EQU (AFIO_BASE + 0x04)
AFIO_EXTICR1 EQU (AFIO_BASE + 0x08)
AFIO_EXTICR2 EQU (AFIO_BASE + 0x0C)
AFIO_EXTICR3 EQU (AFIO_BASE + 0x10)
AFIO_EXTICR4 EQU (AFIO_BASE + 0x14)
;GPIOA register address map
GPIOA_BASE EQU 0x40010800
GPIOA_CRL EQU (GPIOA_BASE + 0x00)
GPIOA_CRH EQU (GPIOA_BASE + 0x04)
GPIOA_IDR EQU (GPIOA_BASE + 0x08)
GPIOA_ODR EQU (GPIOA_BASE + 0x0C)
GPIOA_BSRR EQU (GPIOA_BASE + 0x10)
GPIOA_BRR EQU (GPIOA_BASE + 0x14)
GPIOA_LCKR EQU (GPIOA_BASE + 0x18)
;GPIO C mouth control
GPIOC_BASE EQU 0x40011000
GPIOC_CRL EQU (GPIOC_BASE + 0x00)
GPIOC_CRH EQU (GPIOC_BASE + 0x04)
GPIOC_IDR EQU (GPIOC_BASE + 0x08)
GPIOC_ODR EQU (GPIOC_BASE + 0x0C)
GPIOC_BSRR EQU (GPIOC_BASE + 0x10)
GPIOC_BRR EQU (GPIOC_BASE + 0x14)
GPIOC_LCKR EQU (GPIOC_BASE + 0x18)
;Serial 1 control
USART1_BASE EQU 0x40013800
USART1_SR EQU (USART1_BASE + 0x00)
USART1_DR EQU (USART1_BASE + 0x04)
USART1_BRR EQU (USART1_BASE + 0x08)
USART1_CR1 EQU (USART1_BASE + 0x0c)
USART1_CR2 EQU (USART1_BASE + 0x10)
USART1_CR3 EQU (USART1_BASE + 0x14)
USART1_GTPR EQU (USART1_BASE + 0x18)
;NVIC register address
NVIC_BASE EQU 0xE000E000
NVIC_SETEN EQU (NVIC_BASE + 0x0010)
;SETENA start address of register array
NVIC_IRQPRI EQU (NVIC_BASE + 0x0400)
;start address of the interrupt priority register array
NVIC_VECTTBL EQU (NVIC_BASE + 0x0D08)
;address of vector table offset register
NVIC_AIRCR EQU (NVIC_BASE + 0x0D0C)
;Application interrupt and reset control register address
SETENA0 EQU 0xE000E100
SETENA1 EQU 0xE000E104
;SysTick register address
SysTick_BASE EQU 0xE000E010
SYSTICKCSR EQU (SysTick_BASE + 0x00)
SYSTICKRVR EQU (SysTick_BASE + 0x04)
;FLASH Buffer register address map
FLASH_ACR EQU 0x40022000
;SCB_BASE EQU (SCS_BASE + 0x0D00)
MSP_TOP EQU 0x20005000
;Main stack start value
PSP_TOP EQU 0x20004E00
;Process stack start value
BitAlias_BASE EQU 0x22000000
;Bit-band alias area start address
Flag1 EQU 0x20000200
b_flas EQU (BitAlias_BASE + (0x200*32) + (0*4))
;bit address
b_05s EQU (BitAlias_BASE + (0x200*32) + (1*4))
;bit address
DlyI EQU 0x20000204
DlyJ EQU 0x20000208
DlyK EQU 0x2000020C
SysTim EQU 0x20000210
;constant definition
Bit0 EQU 0x00000001
Bit1 EQU 0x00000002
Bit2 EQU 0x00000004
Bit3 EQU 0x00000008
Bit4 EQU 0x00000010
Bit5 EQU 0x00000020
Bit6 EQU 0x00000040
Bit7 EQU 0x00000080
Bit8 EQU 0x00000100
Bit9 EQU 0x00000200
Bit10 EQU 0x00000400
Bit11 EQU 0x00000800
Bit12 EQU 0x00001000
Bit13 EQU 0x00002000
Bit14 EQU 0x00004000
Bit15 EQU 0x00008000
Bit16 EQU 0x00010000
Bit17 EQU 0x00020000
Bit18 EQU 0x00040000
Bit19 EQU 0x00080000
Bit20 EQU 0x00100000
Bit21 EQU 0x00200000
Bit22 EQU 0x00400000
Bit23 EQU 0x00800000
Bit24 EQU 0x01000000
Bit25 EQU 0x02000000
Bit26 EQU 0x04000000
Bit27 EQU 0x08000000
Bit28 EQU 0x10000000
Bit29 EQU 0x20000000
Bit30 EQU 0x40000000
Bit31 EQU 0x80000000
;vector table
AREA RESET, DATA, READONLY
DCD MSP_TOP ;Initialize the main stack
DCD Start ;reset vector
DCD NMI_Handler ;NMI Handler
DCD HardFault_Handler ;Hard Fault Handler
DCD 0
DCD 0
DCD 0
DCD 0
DCD 0
DCD 0
DCD 0
DCD 0
DCD 0
DCD 0
DCD 0
DCD SysTick_Handler ;SysTick Handler
SPACE 20 ;20 bytes of reserved space
;code snippet
AREA |.text|, CODE, READONLY
;main program starts
ENTRY
;Instructs the program to execute from here
Start
;Clock System Settings
ldr r0, =RCC_CR
ldr r1, [r0]
orr r1, #Bit16
str r1, [r0]
;Enable external crystal oscillator
;start external 8 M crystal oscillator
ClkOk
ldr r1, [r0]
ands r1, #Bit17
beq ClkOk
;Wait for the external crystal to be ready
ldr r1,[r0]
orr r1,#Bit17
str r1,[r0]
;FLASH buffer
ldr r0, =FLASH_ACR
mov r1, #0x00000032
str r1, [r0]
;set up PLL The phase-locked loop multiplier is 7,HSE input is not divided
ldr r0, =RCC_CFGR
ldr r1, [r0]
orr r1, #(Bit18 :OR: Bit19 :OR: Bit20 :OR: Bit16 :OR: Bit14)
orr r1, #Bit10
str r1, [r0]
;start up PLL phase locked loop
ldr r0, =RCC_CR
ldr r1, [r0]
orr r1, #Bit24
str r1, [r0]
PllOk
ldr r1, [r0]
ands r1, #Bit25
beq PllOk
;choose PLL clock as system clock
ldr r0, =RCC_CFGR
ldr r1, [r0]
orr r1, #(Bit18 :OR: Bit19 :OR: Bit20 :OR: Bit16 :OR: Bit14)
orr r1, #Bit10
orr r1, #Bit1
str r1, [r0]
;other RCC Related settings
ldr r0, =RCC_APB2ENR
mov r1, #(Bit14 :OR: Bit4 :OR: Bit2)
str r1, [r0]
;IO port settings
ldr r0, =GPIOC_CRL
ldr r1, [r0]
orr r1, #(Bit28 :OR: Bit29)
;PC.7 output mode,max speed 50 MHz
and r1, #(~Bit30 & ~Bit31)
;PC.7 Universal push-pull output mode
str r1, [r0]
;PA9 Serial port 0 transmitter pin
ldr r0, =GPIOA_CRH
ldr r1, [r0]
orr r1, #(Bit4 :OR: Bit5)
;PA.9 output mode,max speed 50 MHz
orr r1, #Bit7
and r1, #~Bit6
;10: Alternate function push-pull output mode
str r1, [r0]
ldr r0, =USART1_BRR
mov r1, #0x271
str r1, [r0]
;Configure the baud rate-> 115200
ldr r0, =USART1_CR1
mov r1, #0x200c
str r1, [r0]
;USART The module is always enabled Send and receive enable
;71 02 00 00 2c 20 00 00
;AFIO parameter settings
;Systick parameter settings
ldr r0, =SYSTICKRVR
;Systick Install the initial value
mov r1, #9000
str r1, [r0]
ldr r0, =SYSTICKCSR
;set up,start up Systick
mov r1, #0x03
str r1, [r0]
;NVIC
;ldr r0, =SETENA0
;mov r1, 0x00800000
;str r1, [r0]
;ldr r0, =SETENA1
;mov r1, #0x00000100
;str r1, [r0]
;Switch to user-level line program mode
ldr r0, =PSP_TOP
;Initialize thread stack
msr psp, r0
mov r0, #3
msr control, r0
;initialization SRAM register
mov r1, #0
ldr r0, =Flag1
str r1, [r0]
ldr r0, =DlyI
str r1, [r0]
ldr r0, =DlyJ
str r1, [r0]
ldr r0, =DlyK
str r1, [r0]
ldr r0, =SysTim
str r1, [r0]
;main loop
main
ldr r0, =Flag1
ldr r1, [r0]
tst r1, #Bit1
;SysTick yields 0.5s,Position bit 1
beq main ;0.5s flag not yet set
;0.5s flag is set
ldr r0, =b_05s
;bit-band operation clears 0.5s logo
mov r1, #0
str r1, [r0]
bl LedFlas
mov r0, #'H'
bl send_a_char
mov r0, #'e'
bl send_a_char
mov r0, #'l'
bl send_a_char
mov r0, #'l'
bl send_a_char
mov r0, #'o'
bl send_a_char
mov r0, #' '
bl send_a_char
mov r0, #'w'
bl send_a_char
mov r0, #'i'
bl send_a_char
mov r0, #'n'
bl send_a_char
mov r0, #'d'
bl send_a_char
mov r0, #'o'
bl send_a_char
mov r0, #'w'
bl send_a_char
mov r0, #'s'
bl send_a_char
mov r0, #'!'
bl send_a_char
mov r0, #'\n'
bl send_a_char
b main
;Subroutine Serial port 1 sends a character
send_a_char
push {r0 - r3}
ldr r2, =USART1_DR
str r0, [r2]
b1
ldr r2, =USART1_SR
ldr r2, [r2]
tst r2, #0x40
beq b1
;send completed(Transmission complete)wait
pop {r0 - r3}
bx lr
;subroutine led flicker
LedFlas
push {r0 - r3}
ldr r0, =Flag1
ldr r1, [r0]
tst r1, #Bit0
;bit0 flashing flag
beq ONLED ;open at 0 led lamp
;1 off led lamp
ldr r0, =b_flas
mov r1, #0
str r1, [r0]
;Blinking flag position is 0,The next state is to turn on the light
;PC.7 output 0
ldr r0, =GPIOC_BRR
ldr r1, [r0]
orr r1, #Bit7
str r1, [r0]
b LedEx
ONLED
;open at 0 led lamp
ldr r0, =b_flas
mov r1, #1
str r1, [r0]
;Blinking flag position is 1,The next state is to turn off the lights
;PC.7 output 1
ldr r0, =GPIOC_BSRR
ldr r1, [r0]
orr r1, #Bit7
str r1, [r0]
LedEx
pop {r0 - r3}
bx lr
;exception program
NMI_Handler
bx lr
HardFault_Handler
bx lr
SysTick_Handler
ldr r0, =SysTim
ldr r1, [r0]
add r1, #1
str r1, [r0]
cmp r1, #500
bcc TickExit
mov r1, #0
str r1, [r0]
ldr r0, =b_05s
;Greater than or equal to 500 times Clear the clock tick counter Set 0.5s flag bit
;bit band operation set to 1
mov r1, #1
str r1, [r0]
TickExit
bx lr
ALIGN
;by using zero or empty instructions NOP filling,to align the current position with a specified boundary
END
to compile
5. Burning operation
1. Instrument preparation
1. One piece of stm32 core board 103f
2, usb to serial port
3, a breadboard, a number of wires
2 Instrument connection
GND-G
3V3-3.3
RXD-A10
TXD-A9
3 Burn
6. Observe the output waveform
In the absence of an oscilloscope, Keil's software simulation logic analyzer function can be used to observe the timing waveform of the pin, which is more convenient for dynamic tracking and debugging and locating code failure points. Please use this function to observe the output waveforms of the three GPIO ports in question 1, and analyze whether the timing states reflected by the waveforms are correct or not, and what is the actual high-low level transition period (LED blinking period).
1. Set the emulation mode
When using the simulation mode, you need to set the Debug mode. The following figure shows the Debug setting mode.
2. Use a logic analyzer
Be sure to set Display Type to BIt!
Waveform
7. References
usart serial communication of STM32 - Programmer Sought
Use register & HAL library to complete LED running light program_weixin_45203491's blog - CSDN blog