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, imm30) ``Rd = imm30`` movwt is a pseudo-instruction: the MicroPython assembler emits a ``movw`` and a ``movt`` to move a zero extended 30 bit value into Rd. Where the full 32 bits are required a workround is to use the movw and movt operations.