STM32 Bit Banding (or bit-banding)

In older 8-bit MCUs it was quite common to have instructions to clear or set a bit as one atomic instruction. By atomic it means the read->modify->write can not be interrupted resulting in other bits being set wrongly.

Macro's to Calculate Bit Band Address

#define BITBAND_SRAM_REF    0x20000000
#define BITBAND_SRAM_BASE   0x22000000
#define BITBAND_PERIPH_REF  0x40000000
#define BITBAND_PERIPH_BASE 0x42000000

#define bitband_t *(volatile uint32_t*)

#define m_BITBAND_SRAM(address,bit) (BITBAND_SRAM_BASE + (((uint32_t)address) - BITBAND_SRAM_REF) * 32 + (bit) * 4)
#define m_BITBAND_PERIPH(address,bit) (BITBAND_PERIPH_BASE + (((uint32_t)address) - BITBAND_PERIPH_REF) * 32 + (bit) * 4)

Miscellaneous Links

To be added