micro:bit MicroPython register access

micropython_edit_regs.md

• NRF51 peripheral map
• NRF51 bit fields

read_reg_example.py

FICR_BASE_ADDRESS = 0x10000000
CODE_PAGE_SIZE = FICR_BASE_ADDRESS + 0x010
CODE_SIZE = FICR_BASE_ADDRESS + 0x014

@micropython.asm_thumb
def reg_read(r0):
    ldr(r0, [r0, 0])

@micropython.asm_thumb
def reg_write(r0, r1):
    str(r1, [r0, 0])
    
@micropython.asm_thumb
def reg_and(r0, r1):
    ldr(r2, [r0, 0])
    and_(r2, r1)
    str(r2, [r0, 0])

@micropython.asm_thumb
def reg_or(r0, r1):
    ldr(r2, [r0, 0])
    orr(r2, r1)
    str(r2, [r0, 0])

@micropython.asm_thumb
def reg_bit_clear(r0, r1):
    ldr(r2, [r0, 0])
    bic(r2, r1)
    str(r2, [r0, 0])

while True:
    print("Should be 1024: {}".format(reg_read(CODE_PAGE_SIZE)))
    print("Should be 256: {}".format(reg_read(CODE_SIZE)))