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UMULT (Super FX): Difference between revisions
From SnesLab
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The exact number of cycles depends on the state of the [[CONFIG]] register. | The exact number of cycles depends on the state of the [[CONFIG]] register. | ||
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 19:03, 9 July 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | ROM Speed | RAM Speed | Cache Speed | ||
| Implied (type 1) | 3D8n | 2 bytes | 6 or 8 cycles | 6 or 8 cycles | 2 or 3 cycles | ||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| B | ALT1 | ALT2 | O/V | S | CY | Z | ||
| 0 | 0 | 0 | . | . | ||||
UMULT is an unsigned multiplication Super FX instruction. The factors are the low byte of the source register and the low byte of the register specified in the operand. The product is stored in the destination register.
UMULT utilizes the 8-bit multiplier only once, so it is fast.[2]
The exact number of cycles depends on the state of the CONFIG register.
The source and destination registers should be specified in advance using WITH, FROM, or TO. Otherwise, R0 serves as the default.
Syntax
UMULT Rn
Example
Let:
Sreg : R3 Dreg : R0 R3 = 364fh R8 = b2cfh
After executing UMULT R8:
R0 = 3fe1h
See Also
External Links
- Official Nintendo documentation on UMULT: 9.90 on page 2-9-122 of Book II
- 8.2 "Multiplication Instructions" on page 2-8-16 of Book II, lbid.