EOR

Basic Info
Addressing Mode	Opcode	Length	Speed
Immediate	49	2 bytes	2 cycles*
Absolute	4D	3 bytes	4 cycles*
absolute long	4F	4 bytes	5 cycles*
direct page	45	2 bytes	3 cycles*
direct page indirect	52	2 bytes	5 cycles*
direct page indirect long	47	2 bytes	6 cycles*
absolute indexed by X	5D	3 bytes	4 cycles*
absolute long indexed by X	5F	4 bytes	5 cycles*
absolute indexed by Y	59	3 bytes	4 cycles*
direct page indexed by X	55	2 bytes	4 cycles*
direct page indexed indirect by X	41	2 bytes	6 cycles*
direct page indirect indexed by Y	51	2 bytes	5 cycles*
direct page indirect long indexed by Y	57	2 bytes	6 cycles*
stack relative	43	2 bytes	4 cycles*
stack relative indirect indexed by Y	53	2 bytes	7 cycles*

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

EOR is a 65x instruction that performs an exclusive or. In all addressing modes, EOR takes one extra cycle when the accumulator is 16 bits wide. In direct page addressing modes, EOR takes one additional cycle if the low byte of the direct page register is nonzero. In both Absolute Indexed and DP Indirect Indexed, Y admodes, EOR takes an extra cycle if adding the index crosses a page boundary.

See Also

• ORA
• EOR (SPC700)
• XOR (Super FX)

External Links

• Eyes & Lichty page on EOR: https://archive.org/details/0893037893ProgrammingThe65816/page/n480
• Labiak page on EOR: https://archive.org/details/Programming_the_65816/page/n151
• MCS6500 Manual page on EOR: https://archive.org/details/mos_microcomputers_programming_manual/page/n36
• Carr page on EOR: https://archive.org/details/6502UsersManual/page/n272
• Leventhal page on EOR: https://archive.org/details/6502-assembly-language-programming/page/n112
• snes9x implementation of EOR: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L533
• undisbeliever on EOR: https://undisbeliever.net/snesdev/65816-opcodes.html#eor-exclusive-or-accumulator-with-memory