gc80c510 CORERIVER Semiconductor, gc80c510 Datasheet - Page 162

• Manufacturer Part Number: gc80c510
• Description: Eprom/rom 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

Appendix A: Instruction Set
MUL
AB
Multiply
Function:
Description:
MUL AB multiplies the unsigned eight-bit integers in the Accumulator and
register B. The Iow-order byte of the sixteen-bit product is left in the
Accumulator, and the high-order byte in B. If the product is greater than 255
(0FFh) the overflow flag is set; otherwise it is cleared. The carry flag is always
cleared.
Example:
Originally the Accumulator holds the value 80 (50h). Register B holds the value
160 (0A0h). The instruction,
MUL AB
will give the product 12,800 (3200h), so B is changed to 32h (00110010b) and
the Accumulator is cleared. The overflow flag is set, carry is cleared.
1
Bytes:
Cycles:
3
Encoding:
1
0
1
0
0 1 0 0
Operation:
MUL
←
(A)
, (B)
(A) X (B)
7-0
15-8
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