File: asm_thumb2_mov.rst

package info (click to toggle)
micropython 1.25.0%2Bds-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 48,944 kB
  • sloc: ansic: 317,850; python: 59,539; xml: 4,241; makefile: 3,530; sh: 1,421; javascript: 744; asm: 681; cpp: 45; exp: 11; pascal: 6
file content (27 lines) | stat: -rw-r--r-- 850 bytes parent folder | download | duplicates (4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Register move instructions
==========================

Document conventions
--------------------

Notation: ``Rd, Rn`` denote ARM registers R0-R15. ``immN`` denotes an immediate
value having a width of N bits. These instructions affect the condition flags.

Register moves
--------------

Where immediate values are used, these are zero-extended to 32 bits. Thus
``mov(R0, 0xff)`` will set R0 to 255.

* mov(Rd, imm8) ``Rd = imm8``
* mov(Rd, Rn) ``Rd = Rn``
* movw(Rd, imm16) ``Rd = imm16``
* movt(Rd, imm16) ``Rd = (Rd & 0xffff) | (imm16 << 16)``

movt writes an immediate value to the top halfword of the destination register.
It does not affect the contents of the bottom halfword.

* movwt(Rd, imm32) ``Rd = imm32``

movwt is a pseudo-instruction: the MicroPython assembler emits a ``movw`` followed
by a ``movt`` to move a 32-bit value into Rd.