peek_poke.py

# 2019-09-19 SK, MIT license
"""
MicroPython code.
Memory map access using the peek and poke functions.
Tested on nRF52.
"""

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

def int2uint(value):
    value = value + 0x1_0000_0000 if value < 0 else value
    return value

def peek(address):
    value = reg_read(address)
    return int2uint(value)

# Poke
@micropython.asm_thumb
def reg_write(r0, r1): # address, value
    str(r1, [r0, 0])

def poke(address, value):
    reg_write(address, value)
    return peek(address)

# Tests
if __name__ == "__main__":

    address = 0x1000_1000
    print(hex(peek(address)))

    address = 0x20_00_44_40 + 0x10_00 + 42
    value = 0x_af_e5_34_8b
    print(hex(poke(address, value)))