CMPW (SPC700): Difference between revisions

Latest revision as of 13:55, 30 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
N	.	.	.	.	.	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

External Links

Official Nintendo documentation on CMPW: Table C-12 in Appendix C-8 of Book I
anomie: https://github.com/yupferris/TasmShiz/blob/8fabc9764c33a7ae2520a76d80ed7220bb939f12/spc700.txt#L407

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 |[[Carry Flag|C]]
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+|N
 |.
 |.
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 |.
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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 ====
+<pre>
+CMPW YA, dp
+</pre>
 === See Also ===
@@ Line 45: / Line 50: @@
 === External Links ===
 * Official Nintendo documentation on CMPW: Table C-12 in [https://archive.org/details/SNESDevManual/book1/page/n233 Appendix C-8 of Book I]
+* anomie: https://github.com/yupferris/TasmShiz/blob/8fabc9764c33a7ae2520a76d80ed7220bb939f12/spc700.txt#L407
 [[Category:ASM]]
 [[Category:SPC700]]
 [[Category:16-bit Operation Commands]]
+[[Category:Two-byte Instructions]]