PHY: Difference between revisions

Latest revision as of 00:05, 17 August 2024


Basic Info
Addressing Mode	Opcode	Length	Speed
Stack (Push)	5A	1 byte	3 cycles*


Flags Affected
N	V	M	X	D	I	Z	C
.	.	.	.	.	.	.	.

PHY is a 65c816 instruction that pushes the value of the Y index register onto the stack. If Y is 16 bits wide, the high byte is pushed first.

The stack pointer is decremented by the number of bytes Y is.

No flags are affected.

Syntax

PHY

Cycle Penalty

PHY takes one additional cycle if the index registers are 16 bits wide.

External Links

Eyes & Lichty, page 482 on PHY
Labiak, page 166 on PHY
snes9x implementation of PHY: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1921

@@ Line 1: / Line 1: @@
-'''PHY''' is a [[65c816]] instruction that pushes the value of the [[Y index register]] onto the [[stack]].
+{| class="wikitable" style="float:right;clear:right;width:40%"
+!colspan="8"|Basic Info
+|+
+|'''Addressing Mode'''
+|'''Opcode'''
+|'''Length'''
+|'''Speed'''
+|+
+|[[Stack Addressing|Stack]] (Push)
+|5A
+|1 byte
+|3 cycles*
+|}
 {| class="wikitable" style="float:right;clear:right;width:30%"
-!colspan="9"|Flags Clobbered
+!colspan="9"|Flags Affected
 |+
-|N
+|[[Negative Flag|N]]
-|V
+|[[Overflow Flag|V]]
-|M
+|[[M Flag|M]]
-|X
+|[[X Flag|X]]
-|D
+|[[Decimal Flag|D]]
-|I
+|[[I Flag|I]]
-|Z
+|[[Zero Flag|Z]]
-|C
+|[[Carry Flag|C]]
 |+
 |.
@@ Line 22: / Line 34: @@
 |.
 |}
+'''PHY''' is a [[65c816]] instruction that pushes the value of the [[Y index register]] onto the [[stack]].  If Y is 16 bits wide, the high byte is pushed first.
+The [[stack pointer]] is decremented by the number of bytes Y is.
+No flags are affected.
+==== Syntax ====
+<pre>
+PHY
+</pre>
+==== Cycle Penalty ====
+* PHY takes one additional cycle if the index registers are 16 bits wide.
+=== See Also ===
+* [[PHX]]
+* [[PHA]]
+* [[PLY]]
+* [[STY]]
+=== External Links ===
+* [[Eyes & Lichty]], [https://archive.org/details/0893037893ProgrammingThe65816/page/482 page 482] on PHY
+* [[Labiak]], [https://archive.org/details/Programming_the_65816/page/n176 page 166] on PHY
+* snes9x implementation of PHY: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1921
 [[Category:ASM]]
+[[Category:65c02 additions]]
+[[Category:Push Instructions]]
+[[Category:One-byte Instructions]]