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UMULT (Super FX)
From SnesLab
| 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 | ||
| Immediate | |||||||
| 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 or an immediate value. 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.
The page of documentation on the immediate addressing mode of UMULT appears to be missing from the official dev manual.
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.
- Table 2-2-2 Instruction Set (Sheet 1) on page 2-2-6 of Book II, lbid.