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SEC: Difference between revisions
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'''SEC''' is a 65x instruction that sets the [[carry flag]]. | '''SEC''' is a 65x instruction that sets the [[carry flag]]. | ||
Similar to doing a [[CLC]] before an [[ADC]], it is recommended to run SEC (or otherwise make sure the carry flag is set) before running a [[SBC]] so that the difference is correct. | |||
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Revision as of 15:47, 19 May 2023
SEC is a 65x instruction that sets the carry flag.
Similar to doing a CLC before an ADC, it is recommended to run SEC (or otherwise make sure the carry flag is set) before running a SBC so that the difference is correct.
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| implied | 38 | 1 byte | 2 cycles | ||||
| Flags Clobbered | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C | |
| . | . | . | . | . | . | . | 1 | |
See Also
External Links
- Eyes & Lichty page on SEC: https://archive.org/details/0893037893ProgrammingThe65816/page/n525
- Labiak page on SEC: https://archive.org/details/Programming_the_65816/page/n190
- MCS6500 Manual page on SEC: https://archive.org/details/mos_microcomputers_programming_manual/page/n39
- Carr page on SEC: https://archive.org/details/6502UsersManual/page/n285
- Leventhal page on SEC: https://archive.org/details/6502-assembly-language-programming/page/n142
- snes9x implementation of SEC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1427