S3C852B Datasheet, PDF (197/383 Pages) Samsung semiconductor – 8-BIT CMOS MICROCONTROLLERS

S3C852B/P852B (Preliminary Spec)
INSTRUCTION SET
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:
Format:
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.
opc
src
dst
Bytes Cycles
3
22
22
22
Opcode
(Hex)
84
85
86
Addr Mode
dst src
RR R
RR IR
RR IM
Examples:
Given: Register 00H = 20H, register 01H = 03H, register 02H = 09H, register 03H = 06H:
MULT 00H, 02H
→
MULT 00H, @01H →
MULT 00H, #30H →
Register 00H = 01H, register 01H = 20H, register 02H = 09H
Register 00H = 00H, register 01H = 0C0H
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.
6-59