memorymap – Raw memory map access
The memorymap module allows you to read and write memory addresses in the
address space seen from the processor running CircuitPython. It is usually
the physical address space.
Available on these boards
- class memorymap.AddressRange(*, start: int, length: int)
Presents a range of addresses as a bytearray.
The addresses may access memory or memory mapped peripherals.
Some address ranges may be protected by CircuitPython to prevent errors. An exception will be raised when constructing an AddressRange for an invalid or protected address.
Multiple AddressRanges may overlap. There is no “claiming” of addresses.
Example usage on ESP32-S2:
import memorymap rtc_slow_mem = memorymap.AddressRange(start=0x50000000, length=0x2000) rtc_slow_mem[0:3] = b"\xcc\x10\x00"
Example I/O register usage on RP2040:
import binascii import board import digitalio import memorymap def rp2040_set_pad_drive(p, d): pads_bank0 = memorymap.AddressRange(start=0x4001C000, length=0x4000) pad_ctrl = int.from_bytes(pads_bank0[p*4+4:p*4+8], "little") # Pad control register is updated using an MP-safe atomic XOR pad_ctrl ^= (d << 4) pad_ctrl &= 0x00000030 pads_bank0[p*4+0x1004:p*4+0x1008] = pad_ctrl.to_bytes(4, "little") def rp2040_get_pad_drive(p): pads_bank0 = memorymap.AddressRange(start=0x4001C000, length=0x4000) pad_ctrl = int.from_bytes(pads_bank0[p*4+4:p*4+8], "little") return (pad_ctrl >> 4) & 0x3 # set GPIO16 pad drive strength to 12 mA rp2040_set_pad_drive(16, 3) # print GPIO16 pad drive strength print(rp2040_get_pad_drive(16))
Note that the above example does not work on RP2350 because base address and organization of the “pads0” registers changed compared to the RP2040.
Constructs an address range starting at
startand ending atstart + length. An exception will be raised if any of the addresses are invalid or protected.