UM012811-0904
eZ8 CPU Instruction Set Description
eZ8 CPU
User Manual
140
MULT
Multiply
MULT dst
Operation
dst[15:0]
←
dst[15:8] * dst[7:0]
Description
This instruction performs a multiplication of two unsigned 8-bit values with an unsigned
16-bit result. The 16-bit result replaces the two 8-bit values in the Register Pair.
Flags
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address mode RR can specify a Working Register Pair.
If the high nibble of the source or destination address is
EH
(1110B), a Working Register
Pair is inferred. For example, if Working Register Pair R12 and R13 (with base address
CH
) is the desired destination operand, use
ECH
as the destination operand in the opcode.
To access Register Pairs with addresses
E0H
to
EFH
, either set the Working Group Pointer,
RP[7:4], to
EH
or use indirect addressing.
Example
•
Using Escaped Mode Addressing, if Working Register R4 contains the value
86H
and
Working Register R5 contains the value
53H
, the statement:
MULT E4H
Object Code: F4 E4
C
Unaffected.
Z
Unaffected.
S
Unaffected.
V
Unaffected.
D
Unaffected.
H
Unaffected.
Mnemonic
Destination
Opcode (Hex)
Operand 1
Operand 2
Operand 3
MULT
RR1
F4
RR1
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