ORA: Difference between revisions

Revision as of 03:10, 25 November 2023


Basic Info
Addressing Mode	Opcode	Length	Speed
Immediate	09	2 bytes	2 cycles*
Absolute	0D	3 bytes	4 cycles*
Absolute Long	0F	4 bytes	5 cycles*
Direct Page	05	2 bytes	3 cycles*
Direct Page Indirect	12	2 bytes	5 cycles*
Direct Page Indirect Long	07	2 bytes	6 cycles*
absolute indexed by X	1D	3 bytes	4 cycles*
absolute long indexed by X	1F	4 bytes	5 cycles*
absolute indexed by Y	19	3 bytes	4 cycles*
direct page indexed by X	15	2 bytes	4 cycles*
direct page indexed indirect by X	01	2 bytes	6 cycles*
direct page indirect indexed by Y	11	2 bytes	5 cycles*
direct page indirect long indexed by Y	17	2 bytes	6 cycles*
Stack Relative	03	2 bytes	4 cycles*
stack relative indirect indexed by Y	13	2 bytes	7 cycles*


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

ORA is a 65x instruction that performs a logical OR.

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

@@ Line 105: / Line 105: @@
 |}
-'''ORA''' is a 65x instruction that performs a logical OR.  In all [[addressing modes]], ORA takes one extra cycle when the accumulator is 16 bits wide.  In [[direct page addressing]] modes, ORA takes another extra cycle if the low byte of the [[direct page register]] is nonzero.
+'''ORA''' is a 65x instruction that performs a logical OR.
+===== Cycle Penalties =====
+* In all [[addressing modes]], ORA takes one extra cycle when the accumulator is 16 bits wide.
+* In [[direct page addressing]] modes, ORA takes another extra cycle if the low byte of the [[direct page register]] is nonzero.
 === See Also ===