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BRK: Difference between revisions
From SnesLab
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===== Cycle Penalty ===== | ===== Cycle Penalty ===== | ||
BRK takes one | BRK takes one extra cycle in [[native mode]] as it needs to push the [[program counter bank register]] to the [[stack]]. | ||
=== See Also === | === See Also === | ||
Revision as of 03:34, 26 November 2023
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Stack | 00 | 2 bytes | 7 cycles* | ||||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X / B | D | I | Z | C | |
| 65c816 native mode | . | . | . | . | 0 | 1 | . | . |
| 6502 emulation mode | . | . | . | 1 | 0 | 1 | . | . |
BRK (Break) is a 65x instruction designed to trigger a software interrupt. The byte following the opcode is called the Signature Byte. The state of the interrupt disable flag has no effect on the behavior of BRK.
Cycle Penalty
BRK takes one extra cycle in native mode as it needs to push the program counter bank register to the stack.
See Also
External Links
- Eyes & Lichty page 436, on BRK: https://archive.org/details/0893037893ProgrammingThe65816/page/n462
- Labiak page on BRK: https://archive.org/details/Programming_the_65816/page/n136
- MCS6500 Manual page on BRK: https://archive.org/details/mos_microcomputers_programming_manual/page/n164
- Carr page on BRK: https://archive.org/details/6502UsersManual/page/n265
- Leventhal page on BRK: https://archive.org/details/6502-assembly-language-programming/page/n98
- snes9x implementation of BRK: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L2547