SBC

Basic Info
Addressing Mode	Opcode	Length	Speed
Immediate	E9	2/3 bytes	2 cycles*
Absolute	ED	3 bytes	4 cycles*
Absolute Long	EF	4 bytes	5 cycles*
Direct Page	E5	2 bytes	3 cycles*
Direct Page Indirect	F2	2 bytes	5 cycles*
Direct Page Indirect Long	E7	2 bytes	6 cycles*
Absolute Indexed by X	FD	3 bytes	4 cycles*
Absolute Long Indexed by X	FF	4 bytes	5 cycles*
Absolute Indexed by Y	F9	3 bytes	4 cycles*
Direct Page Indexed by X	F5	2 bytes	4 cycles*
Direct Page Indexed Indirect by X	E1	2 bytes	6 cycles*
Direct Page Indirect Indexed by Y	F1	2 bytes	5 cycles*
Direct Page Indirect Long Indexed by Y	F7	2 bytes	6 cycles*
Stack Relative	E3	2 bytes	4 cycles*
Stack Relative Indirect Indexed by Y	F3	2 bytes	7 cycles*

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

SBC (Subtract with Carry/Borrow) is 65x instruction that performs a subtraction.

If the carry flag (aka borrow flag) is clear, one more is subtracted.

The difference is stored in the accumulator.

Syntax

SBC #const
SBC addr
SBC long
SBC dp
SBC (dp)
SBC [dp]
SBC addr, X
SBC long, X
SBC addr, Y
SBC dp, X
SBC (dp, X)
SBC (dp), Y
SBC [dp], Y
SBC sr, S
SBC (sr, S), Y

See Also

• ADC
• SBC (SPC700)
• SUB (Super FX)

External Links

• Eyes & Lichty page 497, on SBC: https://archive.org/details/0893037893ProgrammingThe65816/page/n523
• Labiak page 179 on SBC: https://archive.org/details/Programming_the_65816/page/n189
• MCS6500 Manual page 14 on SBC: https://archive.org/details/mos_microcomputers_programming_manual/page/n29
• Carr page 271 on SBC: https://archive.org/details/6502UsersManual/page/n284
• Leventhal page 3-91 on SBC: https://archive.org/details/6502-assembly-language-programming/page/n140
• snes9x implementation of SBC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1133
• undisbeliever on SBC: https://undisbeliever.net/snesdev/65816-opcodes.html#sbc-subtract-with-borrow-from-accumulator