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TRB: Difference between revisions

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=== External Links ===
=== External Links ===
* [[Eyes & Lichty]] page 513, 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 194 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
* undisbeliever on TRB: https://undisbeliever.net/snesdev/65816-opcodes.html#trb-test-and-reset-memory-bits-against-accumulator
* undisbeliever on TRB: https://undisbeliever.net/snesdev/65816-opcodes.html#trb-test-and-reset-memory-bits-against-accumulator

Revision as of 10:53, 27 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