We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
TRB: Difference between revisions
From SnesLab
(additional cycles) |
(→External Links: page number) |
||
| Line 47: | Line 47: | ||
=== External Links === | === External Links === | ||
* [[Eyes & Lichty]] page on TRB: https://archive.org/details/0893037893ProgrammingThe65816/page/n539 | * [[Eyes & Lichty]] page 513, on TRB: https://archive.org/details/0893037893ProgrammingThe65816/page/n539 | ||
* [[Labiak]] page on TRB: https://archive.org/details/Programming_the_65816/page/n204 | * [[Labiak]] page on TRB: https://archive.org/details/Programming_the_65816/page/n204 | ||
* snes9x implementation of TRB: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1338 | * snes9x implementation of TRB: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1338 | ||
Revision as of 04:03, 21 November 2023
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Absolute | 1C | 3 bytes | 6 cycles* | ||||
| Direct Page | 14 | 2 bytes | 5 cycles* | ||||
| Flags Affected | |||||||
|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C |
| . | . | . | . | . | . | . | |
TRB (Test and Reset Bits) is a 65c816 instruction that tests and resets bits using the accumulator. For each set bit in the accumulator, the corresponding memory bit is cleared. In both addressing modes, TRB takes two additional cycles if the accumulator is 16 bits wide. In direct page addressing, TRB takes another additional cycle if the low byte of the direct page register is nonzero.
See Also
External Links
- Eyes & Lichty page 513, on TRB: https://archive.org/details/0893037893ProgrammingThe65816/page/n539
- Labiak page on TRB: https://archive.org/details/Programming_the_65816/page/n204
- snes9x implementation of TRB: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1338
- undisbeliever on TRB: https://undisbeliever.net/snesdev/65816-opcodes.html#trb-test-and-reset-memory-bits-against-accumulator