STA: Difference between revisions

Revision as of 21:28, 21 November 2023


Basic Info
Addressing Mode	Opcode	Length	Speed
Absolute	8D	3 bytes	4 cycles*
Absolute Long	8F	4 bytes	5 cycles*
Direct Page	85	2 bytes	3 cycles*
direct page indirect	92	2 bytes	5 cycles*
direct page indirect long	87	2 bytes	6 cycles*
absolute indexed by X	9D	3 bytes	4 cycles*
absolute long indexed by X	9F	4 bytes	5 cycles*
absolute indexed by Y	99	3 bytes	4 cycles*
direct page indexed by X	95	2 bytes	4 cycles*
direct page indexed indirect by X	81	2 bytes	6 cycles*
direct page indirect indexed by Y	91	2 bytes	5 cycles*
direct page indirect long indexed by Y	97	2 bytes	6 cycles*
Stack Relative	83	2 bytes	4 cycles*
stack relative indirect indexed by Y	93	2 bytes	7 cycles*


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

STA (Store Accumulator) is a 65x instruction that stores the value of the accumulator.

In all addressing modes, STA takes one additional cycle when the accumulator is 16 bits wide.
In direct page addressing modes, STA takes another additional cycle if the low byte of the direct page register is nonzero.

@@ Line 100: / Line 100: @@
 |}
-'''STA''' (Store Accumulator) is a 65x instruction that stores the value of the [[accumulator]].  In all [[addressing modes]], STA takes one additional cycle when the accumulator is 16 bits wide.  In [[direct page addressing]] modes, STA takes another additional cycle if the low byte of the [[direct page register]] is nonzero.
+'''STA''' (Store Accumulator) is a 65x instruction that stores the value of the [[accumulator]].
+===== Cycle Penalties =====
+* In all [[addressing modes]], STA takes one additional cycle when the accumulator is 16 bits wide.
+* In [[direct page addressing]] modes, STA takes another additional cycle if the low byte of the [[direct page register]] is nonzero.
 === See Also ===