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BNE: Difference between revisions
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'''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. | '''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. | No flags are affected. | ||
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==== 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]]. | ||
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