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MULQU (Unsigned high-speed multiplication instruction: between registers)
[Instruction Format (Macro Name)]
MULQU Dm, Dn
[Assembler Mnemonic]
udf01 Dm, Dn
[Operation]
This instruction performs multiplication quickly using the multiplier of the extension function unit.
The contents of Dm (unsigned 32-bit integer: multiplicand) and Dn (unsigned 32-bit integer: multiplier) are multiplied,
and the upper 32 bits of the results (64 bits) are written into the high-speed multiply register MDRQ and the lower
32 bits into Dn.
The significant value range of the multiplicand stored in Dm before the operation is judged (starting point: LSB,
judgment unit: 2 bytes), and the operation is only performed for the range containing these significant values. In
other words, the smaller the contents stored in Dm, the quicker operation results can be obtained.
[Flag Changes]
Flag
Change
V
*
C
*
N
+
Z
+
[Programming Cautions]
PSW updating by flag changes is delayed by one instruction.
However, Bcc and Lcc instructions can evaluate flags without waiting for flag reflection to PSW.
Undefined
Undefined
1 when MSB of the lower 32 bits of the results is 1; 0 in all other cases
1 when the lower 32 bits of results are 0; 0 in all other cases
Extension Instruction Specifications
Condition
3-13
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