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TSB: Difference between revisions
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''' | {| class="wikitable" style="float:right;clear:right;width:40%" | ||
!colspan="8"|Basic Info | |||
|+ | |||
|'''Addressing Mode''' | |||
|'''Opcode''' | |||
|'''Length''' | |||
|'''Speed''' | |||
|+ | |||
|[[Absolute Addressing | Absolute]] | |||
|0C | |||
|3 bytes | |||
|6 cycles* | |||
|+ | |||
|[[Direct Page Addressing | Direct Page]] | |||
|04 | |||
|2 bytes | |||
|5 cycles* | |||
|} | |||
{| class="wikitable" style="float:right;clear:right;width:30%" | {| class="wikitable" style="float:right;clear:right;width:30%" | ||
!colspan="8"|Flags | !colspan="8"|Flags Affected | ||
|+ | |+ | ||
|N | |[[Negative Flag|N]] | ||
|V | |[[Overflow Flag|V]] | ||
|M | |[[M Flag|M]] | ||
|X | |[[X Flag|X]] | ||
|D | |[[Decimal Flag|D]] | ||
|I | |[[I Flag|I]] | ||
|Z | |[[Zero Flag|Z]] | ||
|C | |[[Carry Flag|C]] | ||
|+ | |+ | ||
|. | |. | ||
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|. | |. | ||
|. | |. | ||
| | |Z | ||
|. | |. | ||
|} | |} | ||
'''TSB''' (Test and Set Bits) is a [[65c816]] instruction that tests and sets bits using the [[accumulator]]. For each set bit of the accumulator, TSB sets the corresponding memory bit. | |||
TSB performs a logical AND (conjunction) and the [[zero flag]] is set or cleared to reflect whether the conjunction is zero. The conjunction itself is discarded. | |||
==== Syntax ==== | |||
<pre> | |||
TSB addr | |||
TSB dp | |||
</pre> | |||
==== Cycle Penalties ==== | |||
* TSB takes two extra cycles if the accumulator is 16 bits wide. | |||
* In [[direct page addressing]], TSB takes another extra cycle if the low byte of the [[direct page register]] is nonzero. | |||
=== See Also === | === See Also === | ||
* [[TRB]] | * [[TRB]] | ||
* [[BIT]] | |||
* [[SEP]] | |||
* [[TSET1]] | |||
=== External Links === | |||
* [[Eyes & Lichty]], [https://archive.org/details/0893037893ProgrammingThe65816/page/514 page 514] on TSB | |||
* [[Labiak]], [https://archive.org/details/Programming_the_65816/page/n205 page 195] on TSB | |||
* snes9x implementation of TSB: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1348 | |||
* undisbeliever on TSB: https://undisbeliever.net/snesdev/65816-opcodes.html#tsb-test-and-set-memory-bits-against-accumulator | |||
[[Category:ASM]] | [[Category:ASM]] | ||
[[Category:Read-Modify-Write Instructions]] | |||
[[Category:Test-and-Change-Bits Instructions]]] | |||
[[Category:65c02 additions]] |
Latest revision as of 17:50, 23 August 2024
Basic Info | |||||||
---|---|---|---|---|---|---|---|
Addressing Mode | Opcode | Length | Speed | ||||
Absolute | 0C | 3 bytes | 6 cycles* | ||||
Direct Page | 04 | 2 bytes | 5 cycles* |
Flags Affected | |||||||
---|---|---|---|---|---|---|---|
N | V | M | X | D | I | Z | C |
. | . | . | . | . | . | Z | . |
TSB (Test and Set Bits) is a 65c816 instruction that tests and sets bits using the accumulator. For each set bit of the accumulator, TSB sets the corresponding memory bit.
TSB performs a logical AND (conjunction) and the zero flag is set or cleared to reflect whether the conjunction is zero. The conjunction itself is discarded.
Syntax
TSB addr TSB dp
Cycle Penalties
- TSB takes two extra cycles if the accumulator is 16 bits wide.
- In direct page addressing, TSB takes another extra cycle if the low byte of the direct page register is nonzero.
See Also
External Links
- Eyes & Lichty, page 514 on TSB
- Labiak, page 195 on TSB
- snes9x implementation of TSB: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1348
- undisbeliever on TSB: https://undisbeliever.net/snesdev/65816-opcodes.html#tsb-test-and-set-memory-bits-against-accumulator]