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'''TSB''' (Test and Set Bits) is a [[65c816]] instruction that tests and sets bits.
{| class="wikitable" style="float:right;clear:right;width:40%"
 
{| class="wikitable" style="float:right;clear:right;width:30%"
!colspan="8"|Basic Info
!colspan="8"|Basic Info
|+
|+
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|'''Speed'''
|'''Speed'''
|+
|+
|absolute
|[[Absolute Addressing | Absolute]]
|0C
|0C
|3 bytes
|3 bytes
|6 cycles
|6 cycles*
|+
|+
|direct page
|[[Direct Page Addressing | Direct Page]]
|04
|04
|2 bytes
|2 bytes
|5 cycles
|5 cycles*
|}
|}


{| class="wikitable" style="float:right;clear:right;width:30%"
{| class="wikitable" style="float:right;clear:right;width:30%"
!colspan="8"|Flags Clobbered
!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: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

See Also

External Links