TXA: Difference between revisions

Latest revision as of 21:13, 7 August 2024


Basic Info
Addressing Mode	Opcode	Length	Speed
Implied (type 1)	8A	1 byte	2 cycles


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

TXA is a 65x instruction that transfers the value of the X index register to the accumulator.


Instruction Behavior
	8-bit accumulator (m=1)	16-bit accumulator (m=0)
8-bit index registers (x=1)	8 bits are transferred	8 bits are transferred to the low byte of accumulator and high byte of the accumulator is zeroed
16-bit index registers (x=0)	8 bits are transferred	16 bits are transferred

Syntax

TXA

External Links

Eyes & Lichty, page 517 on TXA
Labiak, page 198 on TXA
7.12 on MCS6500 Manual, page 100 on TXA
Carr, page 276 on TXA
Leventhal, page 3-102 on TXA
snes9x implementation of TXA: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L2384

@@ Line 1: / Line 1: @@
-'''TXA''' is a 65x instruction that transfers the value of the [[X index register]] to the [[accumulator]].
+{| class="wikitable" style="float:right;clear:right;width:40%"
-{| class="wikitable" style="float:right;clear:right;width:30%"
 !colspan="8"|Basic Info
 |+
@@ Line 9: / Line 7: @@
 |'''Speed'''
 |+
-|implied
+|[[Implied]] (type 1)
 |8A
 |1 byte
@@ Line 16: / Line 14: @@
 {| class="wikitable" style="float:right;clear:right;width:30%"
-!colspan="8"|Flags Clobbered
+!colspan="8"|Flags Affected
+|+
+|[[Negative Flag|N]]
+|[[Overflow Flag|V]]
+|[[M Flag|M]]
+|[[X Flag|X]]
+|[[Decimal Flag|D]]
+|[[I Flag|I]]
+|[[Zero Flag|Z]]
+|[[Carry Flag|C]]
 |+
 |N
-|V
-|M
-|X
-|D
-|I
-|Z
-|C
-|+
-|
 |.
 |.
@@ Line 33: / Line 31: @@
 |.
 |.
+|Z
+|.
+|}
+'''TXA''' is a 65x instruction that transfers the value of the [[X index register]] to the [[accumulator]].
+{| class="wikitable" style="float:right;clear:right;width:40%"
+!colspan="3"|Instruction Behavior
+|+
 |
-|.
+|'''8-bit accumulator (m=1)'''
+|'''16-bit accumulator (m=0)'''
+|+
+|'''8-bit index registers (x=1)'''
+|8 bits are transferred
+|8 bits are transferred to the low byte of accumulator and high byte of the accumulator is zeroed
+|+
+|'''16-bit index registers (x=0)'''
+|8 bits are transferred
+|16 bits are transferred
 |}
+==== Syntax ====
+<pre>
+TXA
+</pre>
 === See Also ===
 * [[TYA]]
+* [[TAX]]
+* [[TXY]]
+* [[STX]]
+* [[TXS]]
 === External Links ===
-* [[Eyes & Lichty]] page on TXA: https://archive.org/details/0893037893ProgrammingThe65816/page/n543
+* [[Eyes & Lichty]], [https://archive.org/details/0893037893ProgrammingThe65816/page/517 page 517] on TXA
-* [[Labiak]] page on TXA: https://archive.org/details/Programming_the_65816/page/n208
+* [[Labiak]], [https://archive.org/details/Programming_the_65816/page/n208 page 198] on TXA
+* 7.12 on [[MCS6500 Manual]], [https://archive.org/details/mos_microcomputers_programming_manual/page/n118 page 100] on TXA
+* [[Carr]], [https://archive.org/details/6502UsersManual/page/n289 page 276] on TXA
+* [[Leventhal]], [https://archive.org/details/6502-assembly-language-programming/page/n151 page 3-102] on TXA
+* snes9x implementation of TXA: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L2384
 [[Category:ASM]]
 [[Category:Inherited from 6502]]
+[[Category:Transfer Instructions]]
+[[Category:One-byte Instructions]]
+[[Category:Implied Instructions]]
+[[Category:Two-cycle Instructions]]