Mult – Samsung S3F80JB User Manual
Page 187
S3F80JB
INSTRUCTION SET
6-59
MULT
—
Multiply (Unsigned)
MULT
dst,src
Operation: dst
← dst × src
The 8-bit destination operand (even register of the register pair) is multiplied by the source
operand (8 bits) and the product (16 bits) is stored in the register pair specified by the destination
address. Both operands are treated as unsigned integers.
Flags: C:
Set if result is
> 255; cleared otherwise.
Z: Set if the result is "0"; cleared otherwise.
S: Set if MSB of the result is a "1"; cleared otherwise.
V: Cleared.
D: Unaffected.
H: Unaffected.
Format:
Bytes Cycles Opcode
(Hex)
Addr Mode
dst src
opc src dst
3 22 84 RR
R
22 85
RR
IR
22 86
RR
IM
Examples:
Given: Register 00H = 20H, register 01H = 03H, register 02H = 09H, register 03H = 06H:
MULT 00H,
02H
→
Register 00H = 01H, register 01H = 20H, register 02H = 09H
MULT 00H,
@01H
→
Register 00H = 00H, register 01H = 0C0H
MULT 00H,
#30H
→
Register 00H = 06H, register 01H = 00H
In the first example, the statement "MULT 00H,02H" multiplies the 8-bit destination operand (in
the register 00H of the register pair 00H, 01H) by the source register 02H operand (09H). The
16-bit product, 0120H, is stored in the register pair 00H, 01H.