DECW (SPC700): Difference between revisions

Latest revision as of 12:23, 30 July 2024


Basic Info
Addressing Mode	Opcode	Length	Speed
Direct Page	1A	2 bytes	6 cycles


Flags Affected
N	V	P	B	H	I	Z	C
N	.	.	.	.	.	Z	.

DECW is an SPC700 command that decrements a 16-bit word of the direct page.

DECW dp

@@ Line 1: / Line 1: @@
-'''DECW''' is an [[SPC700]] command that decrements a word.
+{| class="wikitable" style="float:right;clear:right;width:40%"
-{| class="wikitable" style="float:right;clear:right;width:30%"
 !colspan="8"|Basic Info
 |+
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 |'''Speed'''
 |+
-|
+|[[Direct Page Addressing | Direct Page]]
 |1A
 |2 bytes
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 {| class="wikitable" style="float:right;clear:right;width:30%"
-!colspan="8"|Flags Clobbered
+!colspan="8"|Flags Affected
+|+
+|[[Negative Flag|N]]
+|[[Overflow Flag|V]]
+|[[Direct Page Flag|P]]
+|[[Break Flag|B]]
+|[[Half-Carry Flag|H]]
+|[[Interrupt Enable Flag|I]]
+|[[Zero Flag|Z]]
+|[[Carry Flag|C]]
 |+
 |N
-|V
-|P
-|B
-|H
-|I
-|Z
-|C
-|+
-|
 |.
 |.
@@ Line 33: / Line 31: @@
 |.
 |.
-|
+|Z
 |.
 |}
+'''DECW''' is an [[SPC700]] command that decrements a 16-bit word of the [[direct page]].
+==== Syntax ====
+<pre>
+DECW dp
+</pre>
+=== See Also ===
+* [[INCW]]
+* [[MOVW]]
+* [[DEC (SPC700)]]
+* [[DEC]]
+* [[Memory Pair]]
+=== External Links ===
+* Official Super Nintendo development manual on DECW: 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/master/spc700.txt#L422
 [[Category:ASM]]
 [[Category:SPC700]]
 [[Category:16-bit Operation Commands]]
+[[Category:Two-byte Instructions]]