Bit-banding on STM32L series

[infoinfo988]

Posted on June 03, 2011 at 11:50

Hi,

I'm trying to get bit-banding to work on STM32L series. It seems that some header  definitions have changed between STM32F and STM32L so it's not clear how bit-banding should be implemented. I've tried the following: &sharpdefine BITBAND_PERI_REF   0x40000000 &sharpdefine BITBAND_PERI_BASE  0x42000000 &sharpdefine BITBAND_PERI(a,b) ((BITBAND_PERI_BASE + (a-BITBAND_PERI_REF)*32 + (b*4)))  // Convert PERI address //Offset of ODR in GPIO_TypeDef = 0x14? //GPIOA ODR = 0x40000000 + 0x00020000 + 0x000 + 0x14 //GPIOB ODR = 0x40000000 + 0x00020000 + 0x400 + 0x14 //GPIOC ODR = 0x40000000 + 0x00020000 + 0x800 + 0x14 //GPIOD ODR = 0x40000000 + 0x00020000 + 0xC00 + 0x14 &sharpdefine GPIOA_BB(b) *((volatile uint32_t *)(BITBAND_PERI(0x40020014,b))) &sharpdefine GPIOB_BB(b) *((volatile uint32_t *)(BITBAND_PERI(0x40020414,b))) &sharpdefine GPIOC_BB(b) *((volatile uint32_t *)(BITBAND_PERI(0x40020814,b))) &sharpdefine GPIOD_BB(b) *((volatile uint32_t *)(BITBAND_PERI(0x40020C14,b))) But it doesn't seem to work. Any ideas on how we can solve this? Thanks. #bit-banding-stm32l

[Tesla DeLorean]

Posted on June 03, 2011 at 15:15

The following seems to be viable on the STM32L platform, with a Keil compiler.

Not sure what you're using, but you could verify the actual addresses of the pointers you are using to confirm they match the correct values. { // STM32L152-EVAL Test     volatile unsigned long *odr_a            = (volatile unsigned long *)0x40020014;     volatile unsigned long *odr_a_bb    = (volatile unsigned long *)0x42400280;     sprintf(text,''%08X %08X'',*odr_a,GPIOA->ODR);   GLCD_DisplayString(0, 0, (unsigned char *)text);     odr_a_bb[0] = 1;     odr_a_bb[4] = 1;     sprintf(text,''%08X %08X'',*odr_a,GPIOA->ODR);   GLCD_DisplayString(1, 0, (unsigned char *)text);     odr_a_bb[0] = 0;     odr_a_bb[8] = 1;     sprintf(text,''%08X %08X'',*odr_a,GPIOA->ODR);   GLCD_DisplayString(2, 0, (unsigned char *)text); } The output is 00000000 00000000 00000011 00000011 00000110 00000110