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CMPW (SPC700): Difference between revisions
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'''CMPW''' (Compare Word) is an [[SPC700]] command that performs a comparsion between [[YA]] and a 16-bit word in the [[direct page]]. Internally, this is done by the [[ALU]] subtracting the direct page word from YA, but the difference is not stored anywhere. | '''CMPW''' (Compare Word) is an [[SPC700]] command that performs a comparsion between [[YA]] and a 16-bit word in the [[direct page]]. Internally, this is done by the [[ALU]] subtracting the direct page word from YA, but the difference is not stored anywhere - the side effect is the N, Z, and C flags being modified. | ||
==== Syntax ==== | ==== Syntax ==== |
Revision as of 01:41, 13 July 2024
Basic Info | |||||||
---|---|---|---|---|---|---|---|
Addressing Mode | Opcode | Length | Speed | ||||
Direct Page | 5A | 2 bytes | 4 cycles |
Flags Affected | |||||||
---|---|---|---|---|---|---|---|
N | V | P | B | H | I | Z | C |
. | . | . | . | . |
CMPW (Compare Word) is an SPC700 command that performs a comparsion between YA and a 16-bit word in the direct page. Internally, this is done by the ALU subtracting the direct page word from YA, but the difference is not stored anywhere - the side effect is the N, Z, and C flags being modified.
Syntax
CMPW YA, dp
See Also
External Links
- Official Nintendo documentation on CMPW: Table C-12 in Appendix C-8 of Book I