5
INSTRUCTION SET
34
EPSON
S1C33 FAMILY C33 PE CORE MANUAL
5
.
10
Multiply Instructions
The instruction set of the C
33
PE Core includes four multiplication instructions.
mlt.h
16
bits
×
16
bits
→
32
bits (signed)
mltu.h
16
bits
×
16
bits
→
32
bits (unsigned)
mlt.w
32
bits
×
32
bits
→
64
bits (signed)
mltu.w
32
bits
×
32
bits
→
64
bits (unsigned)
The data in the specified general-purpose registers (R
0
–R
15
) is used for the multiplier and the multiplicand,
respectively. For
16
-bit multiplications, the
16
low-order bits in the specified register are used. The signed
multiplication instructions use the MSB in the multiplier and multiplicand as the sign bit.
The result of a
16
-bit
×
16
-bit operation is loaded into the ALR. The result of a
32
-bit
×
32
-bit operation is loaded
into the AHR and ALR, with the
32
high-order bits stored in the former and the
32
low-order bits stored in the
latter.
The C
33
PE Core executes
16
-bit
×
16
-bit multiplication in five cycle and
32
-bit
×
32
-bit multiplication in seven
cycles.
