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GETBL (Super FX): Difference between revisions
From SnesLab
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The reason the cycle times can vary is because of the [[ROM buffer]]. | The reason the cycle times can vary is because of the [[ROM buffer]]. | ||
The source and destination registers should be specified in advance using [[WITH]], [[FROM]], or [[TO]]. Otherwise, R<sub>0</sub> serves as the default. | |||
==== Syntax ==== | ==== Syntax ==== | ||
Revision as of 18:41, 9 July 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | ROM Speed | RAM Speed | Cache Speed | ||
| Implied (type 1) | 3EEF | 2 bytes | 6 to 10 cycles | 6 to 9 cycles | 2 to 6 cycles | ||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| B | ALT1 | ALT2 | O/V | S | CY | Z | ||
| 0 | 0 | 0 | . | . | . | . | ||
GETBL (Get Byte Low) is a Super FX instruction that loads one byte from the ROM buffer into the low byte of the destination register. GETBL also loads the high byte of the source register into the high byte of the destination register.
The reason the cycle times can vary is because of the ROM buffer.
The source and destination registers should be specified in advance using WITH, FROM, or TO. Otherwise, R0 serves as the default.
Syntax
GETBL
Example
Let:
(ROM Buffer) = 75h Sreg : R2 Dreg : R6 R2 = 4abdh
After executing GETBL:
R6 = 4a75h
See Also
External Links
- Official Super Nintendo development manual on GETBL: 9.37 on page 2-9-53 of Book II
- example: page 2-9-54 of Book II, lbid