SUBW (SPC700): Difference between revisions

Latest revision as of 14:40, 30 July 2024


Basic Info
Addressing Mode	Opcode	Length	Speed
Direct Page	9A	2 bytes	5 cycles


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

SUBW (Subtract Word) is an SPC700 command that subtracts a 16-bit direct page word from YA. The difference is stored in YA.

SUBW YA, dp

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-'''SUBW''' is an [[SPC700]] command that stores a difference in [[YA]].
+{| 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]]
 |9A
 |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
-|+
-|
-|
-|.
-|.
-|
-|.
-|
-|
 |}
+'''SUBW''' (Subtract Word) is an [[SPC700]] command that subtracts a 16-bit [[direct page]] word from [[YA]].  The difference is stored in YA.
+==== Syntax ====
+<pre>
+SUBW YA, dp
+</pre>
+=== See Also ===
+* [[ADDW]]
+* [[CMPW]]
+* [[MOVW]]
+* [[SBC (SPC700)]]
+=== External Links ===
+* Official Super Nintendo development manual on SUBW: 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#L587
 [[Category:ASM]]
 [[Category:SPC700]]
 [[Category:16-bit Operation Commands]]
+[[Category:Two-byte Instructions]]