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BNE: Difference between revisions
From SnesLab
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|'''Speed''' | |'''Speed''' | ||
|+ | |+ | ||
| | |[[Program Counter Relative]] | ||
|D0 | |D0 | ||
|2 | |2 bytes | ||
|2 cycles* | |2 cycles* | ||
|} | |} | ||
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!colspan="9"|Flags Affected | !colspan="9"|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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|} | |} | ||
'''BNE''' (Branch if Not Equal) is a 65x instruction that performs a jump if the [[zero flag]] is clear. | '''BNE''' (Branch if Not Equal) is a 65x instruction that performs a jump if the [[zero flag]] is clear. The displacement may be -128 to 127. | ||
===== Cycle Penalties | If the zero flag is set, control simply falls through to the instruction following BNE. | ||
No flags are affected. | |||
==== Syntax ==== | |||
<pre> | |||
BNE nearlabel | |||
</pre> | |||
==== Cycle Penalties ==== | |||
* BNE takes one additional cycle if the branch is taken | * BNE takes one additional cycle if the branch is taken | ||
* BNE takes another extra cycle if that branch taken crosses a page boundary in [[emulation mode]]. | * BNE takes another extra cycle if that branch taken crosses a page boundary in [[emulation mode]]. | ||
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=== External Links === | === External Links === | ||
* [[Eyes & Lichty]] | * [[Eyes & Lichty]], [https://archive.org/details/0893037893ProgrammingThe65816/page/433 page 433] on BNE | ||
* [[Labiak]] | * [[Labiak]], [https://archive.org/details/Programming_the_65816/page/n133 page 123] on BNE | ||
* [[MCS6500 Manual]] | * 4.1.2.6 on [[MCS6500 Manual]], [https://archive.org/details/mos_microcomputers_programming_manual/page/n56 page 41] on BNE | ||
* [[Carr]] | * [[Carr]], [https://archive.org/details/6502UsersManual/page/n264 page 251] on BNE | ||
* [[Leventhal]] | * [[Leventhal]], [https://archive.org/details/6502-assembly-language-programming/page/n96 page 3-47] on BNE | ||
* snes9x implementation of BNE: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1380 | * snes9x implementation of BNE: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1380 | ||
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[[Category:Inherited from 6502]] | [[Category:Inherited from 6502]] | ||
[[Category:Conditional Branches]] | [[Category:Conditional Branches]] | ||
[[Category:Two-byte Instructions]] | |||
Latest revision as of 20:56, 15 August 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Program Counter Relative | D0 | 2 bytes | 2 cycles* | ||||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C | |
| . | . | . | . | . | . | . | . | |
BNE (Branch if Not Equal) is a 65x instruction that performs a jump if the zero flag is clear. The displacement may be -128 to 127.
If the zero flag is set, control simply falls through to the instruction following BNE.
No flags are affected.
Syntax
BNE nearlabel
Cycle Penalties
- BNE takes one additional cycle if the branch is taken
- BNE takes another extra cycle if that branch taken crosses a page boundary in emulation mode.
See Also
External Links
- Eyes & Lichty, page 433 on BNE
- Labiak, page 123 on BNE
- 4.1.2.6 on MCS6500 Manual, page 41 on BNE
- Carr, page 251 on BNE
- Leventhal, page 3-47 on BNE
- snes9x implementation of BNE: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1380