7 years, 3 months ago.

Nucleo 144 boards and GPIO HAL - Not all ports work

Hello,

I'm trying to remove MBED generalized HAL abstractions from my STMicro Nucleo-144 board based project and am getting strange behavior. I'm moving from the platform agnostic DigitalIN, DigitalOut, PortIn, PortOut to STMicro port specific references such as PORTB->MODER.

For some ports, my GPIO initialization and use of GPIOs works(Port D seems to work correctly), but PORTB and PORTC are not working with the HAL abstractions. For example, setting PORTB->MODER has no effect and the value remains at 0x00000280(the reset value). In fact all of the other PORTB-> registers (OTYPER, OSPEEDR, PUPDR) all return 0x00000280, which is not correct. If I remove HAL abstractions and "poke" the register directly in this way:

• (int*)0x40020400 |= 0x10004001; Set Nucleo LEDS as outputs

The write takes effect. This leads me to believe something is amiss in the HAL stack. For now, I'm just going to make my own HAL header file for the GPIO registers, but this seems like it should be addressed(pun intended).

I get the same behavior on both an F746 Nucleo and an F446 Nucleo board that I tested. It doesn't appear that any ports have their configuration locked.

UPDATE:

It appears that the HAL headers are not he problem. When I hard code the register address, the write takes effect, but after a short time, the register reverts back to it's reset value. Look at the example program below:

1. include "mbed.h"

Serial pc(USBTX, USBRX);

1. define GPIOB_MODER *(uint32_t*)0x40020400

int main(void) {

pc.printf("Before:\t%0.8x\r\n", GPIOB_MODER); GPIOB_MODER |= 0x10004001; pc.printf("After:\t%0.8x\r\n", GPIOB_MODER); pc.printf("After:\t%0.8x\r\n", GPIOB_MODER);

}

The output is:

Before: 00000280 After: 10004281 After: 00000280

If I use the already configured GPIOB->MODER for the register references, the extra processor time spend doing the redirection actually allows the register to revert before the first read completes, so I never see the written value stick.

Is there something under the mbed hood that is stepping on my register accesses? I see this behavior for both GPIOB and GPIOC, but GPIOD behaves as expected...

#include "mbed.h"

DigitalOut myled1(LED1);
DigitalOut myled2(LED2);
DigitalOut myled3(LED3);
volatile int * _GPIOBp = (volatile int *) 0x40020400;
int main() {
    while(1) {
        myled1 = 1; // LED is ON
        wait(0.2); // 200 ms
        myled1 = 0; // LED is OFF
        myled2 = 1; // LED is OFF
        wait(0.2); // 200 ms
        myled2 = 0; // LED is OFF
        myled3 = 1; // LED is OFF
        wait(0.2); // 200 ms
        myled3 = 0; // LED is OFF
        wait(1.0); // 1 sec
        printf("My ports are %08X %08X %08X\r\n",_GPIOBp[0], _GPIOBp[1], _GPIOBp[2]);
        printf("loop\r\n");
    }
}

#include "mbed.h"

//DigitalOut myled1(LED1);
//DigitalOut myled2(LED2);
//DigitalOut myled3(LED3);
volatile int * _GPIOBp = (volatile int *) 0x40020400;
volatile int * _GPIOB_DATp = (volatile int *) 0x40020418;
int main() {
    SET_BIT(RCC->AHB1ENR, RCC_AHB1ENR_GPIOBEN);\
    for(int i=0; i < 10000; i++);
    _GPIOBp[0] = 0x10004281;
    _GPIOBp[1] = 0x00000000;
    _GPIOBp[2] = 0x200080C2;
    while(1) {
        *_GPIOB_DATp = (1 << 0); // LED is ON
        wait(0.2); // 200 ms
        *_GPIOB_DATp = (1 << 16); // LED is OFF
        *_GPIOB_DATp = (1 << 7); // LED is ON
        wait(0.2); // 200 ms
        *_GPIOB_DATp = (1 << 23); // LED is ON
        *_GPIOB_DATp = (1 << 14); // LED is ON
        wait(0.2); // 200 ms
        *_GPIOB_DATp = (1 << 30); // LED is ON
        wait(1.0); // 1 sec
        printf("My ports are %08X %08X %08X\r\n",_GPIOBp[0], _GPIOBp[1], _GPIOBp[2]);
        printf("loop\r\n");
    }
}