Instruction: Set a register's source field to a value.

MOVS Destination, < # > Value

Result: Value is stored in Destination' s-field (bits 8..0).

Destination (d-field) is the register whose source field (bits 8..0) is set to Value's value.
Value (s-field) is a register or a 9-bit literal whose value is stored into Destination's source field.

Opcode Table:

–INSTR– ZCRI –CON– –DEST– –SRC–	Z Result	C Result	Result	Clocks
010100 001i 1111 ddddddddd sssssssss	Result = 0	—	Written	4

Concise Truth Table:

In					Out
Destination	Source	Z	C	Effects	Destination	Z	C
$0000_0000; 0	$0000_0000; 0	-	-	wz wc	$0000_0000; 0	1	0
$0000_0000; 0	$0000_01FF; 511	-	-	wz wc	$0000_01FF; 511	0	1
$FFFF_FFFF; -1	$0000_01FF; 511	-	-	wz wc	$FFFF_FFFF; -1	0	0
$FFFF_FFFF; -1	$0000_0000; 0	-	-	wz wc	$FFFF_FE00; -512	0	0

Explanation

MOVS copies the 9-bit value of Value into Destination's source field (s-field) bits 8..0. Destination's other bits are left unchanged. This instruction is handy for setting certain registers like CTRA and VCFG, and for updating the source field of instructions in self-modifying code.

For self-modifying code, ensure that at least one other instruction is executed between a MOVS instruction and the target instruction that MOVS modifies. This gives the cog time to write MOVS's result before it fetches the target instruction for execution; otherwise, the as-yet-unmodified version of the target instruction would be fetched and executed.

If the WZ effect is specified, the Z flag is set (1) if Value equals zero. The result is written to Destination unless the NR effect is specified.