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INC: Difference between revisions
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'''INC''' (Increment) is a 65x instruction that increments the value in the location specified by the operand. | '''INC''' (Increment) is a 65x instruction that increments the value in the location specified by the operand. The size of the [[accumulator]] determines whether this is an 8 or 16 bit operation. | ||
INC ignores the [[decimal mode flag]]. | |||
===== Cycle Penalties ===== | ===== Cycle Penalties ===== | ||
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=== External Links === | === External Links === | ||
* [[Eyes & Lichty]] page 456, on INC: https://archive.org/details/0893037893ProgrammingThe65816/page/n482 | * [[Eyes & Lichty]] page 456, on INC: https://archive.org/details/0893037893ProgrammingThe65816/page/n482 | ||
* [[Labiak]] page on INC: https://archive.org/details/Programming_the_65816/page/n152 | * [[Labiak]] page 142 on INC: https://archive.org/details/Programming_the_65816/page/n152 | ||
* [[MCS6500 Manual]] page on INC: https://archive.org/details/mos_microcomputers_programming_manual/page/n176 | * [[MCS6500 Manual]] page 155 on INC: https://archive.org/details/mos_microcomputers_programming_manual/page/n176 | ||
* [[Carr]] page on INC: https://archive.org/details/6502UsersManual/page/n273 | * [[Carr]] page 260 on INC: https://archive.org/details/6502UsersManual/page/n273 | ||
* [[Leventhal]] page on INC: https://archive.org/details/6502-assembly-language-programming/page/n114 | * [[Leventhal]] page 3-65 on INC: https://archive.org/details/6502-assembly-language-programming/page/n114 | ||
* snes9x implementation of INC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L627 | * snes9x implementation of INC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L627 | ||
* undisbeliever on INC: https://undisbeliever.net/snesdev/65816-opcodes.html#inc-increment | * undisbeliever on INC: https://undisbeliever.net/snesdev/65816-opcodes.html#inc-increment | ||
Latest revision as of 02:07, 10 December 2023
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Accumulator | 1A | 1 byte | 2 cycles | ||||
| Absolute | EE | 3 bytes | 6 cycles* | ||||
| Direct Page | E6 | 2 bytes | 5 cycles* | ||||
| absolute indexed X | FE | 3 bytes | 7 cycles* | ||||
| direct page indexed X | F6 | 2 bytes | 6 cycles* | ||||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C | |
| . | . | . | . | . | . | |||
INC (Increment) is a 65x instruction that increments the value in the location specified by the operand. The size of the accumulator determines whether this is an 8 or 16 bit operation.
INC ignores the decimal mode flag.
Cycle Penalties
- Except in accumulator addressing, INC takes two extra cycles when the accumulator is 16 bits wide.
- In direct page addressing modes, INC takes an extra cycle if the low byte of the direct page register is nonzero.
See Also
External Links
- Eyes & Lichty page 456, on INC: https://archive.org/details/0893037893ProgrammingThe65816/page/n482
- Labiak page 142 on INC: https://archive.org/details/Programming_the_65816/page/n152
- MCS6500 Manual page 155 on INC: https://archive.org/details/mos_microcomputers_programming_manual/page/n176
- Carr page 260 on INC: https://archive.org/details/6502UsersManual/page/n273
- Leventhal page 3-65 on INC: https://archive.org/details/6502-assembly-language-programming/page/n114
- snes9x implementation of INC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L627
- undisbeliever on INC: https://undisbeliever.net/snesdev/65816-opcodes.html#inc-increment