Movex

Destination <-- Source

Affected Flags
C	V	N	Z
		X	X

The movex instruction take a constant defined by only few bits and expand it on the fly to the full 32 bits of the destination register. The "movex" instruction is an optimized version of the move instruction. It's purpose is to make faster loading of little numbers into registers. On a risc processor, many instructions works only on register values and lack immediate addressing modes. Loading performance of "working values" can be a bottleneck in such kind of architecture.
This instruction can work with many different size : 4, 8, 16 bits input constant (.n, .b, .w) and an additionnal flag for signed values (.sn,.sb,.sw).

Forms and variants

rx = Destination register number (Can be a number between 0 and 15 included.)

Form	Effect
movex.n #4BitsImmediateValue,rx	ImmediateValue -> Extended_32_bits -> rx
movex.sn #4BitsSignedImmValue,rx
movex.b #8BitsImmediateValue,rx
movex.sb#8BitsSignedImmValue,rx
movex.w #16bitsImmediateValue,rx
movex.sw#16BitsSignedImmValue,rx

Instruction encoding

I = Immediate value
D = Destination Register

Instruction	Op Code	Cycles	Encoding
movex.un #_4BitsSignedValue,rx	8B	4	10001011 IIIIDDDD
movex.sn #_4BitsSignedValue,rx	8A	4	10001010 IIIIDDDD
movex.b #8BitsUnsignedValue,rx	0B	6	00001011 0000DDDD IIIIIIII
movex.sb #_8BitsSignedValue,rx	0A	6	00001010 0000DDDD IIIIIIII
movex.w #16BitsUnsignedValue,rx	4B	8	01001011 0000DDDD IIIIIIII IIIIIIII
movex.sw #16BitsSignedValue,rx	4A	8	01001010 0000DDDD IIIIIIII IIIIIIII

Movex

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