HT80C51 Datasheet, PDF (117/132 Pages) List of Unclassifed Manufacturers – User Manual Document Information

HT80C51 User Manual
80C51 Family Instruction Set – Instruction definitions
Handshake Solutions
MOVX A,@DPTR
Bytes: 1
Cycles: 2
Encoding: _{1 1 1 0 0 0 0 0}
Operation: MOVX
(A) ← ((DPTR))
MOVX @Ri,A
Bytes: 1
Cycles: 2
Encoding: _{1 1 1 1 0 0 1 i}
Operation: MOVX
((Ri)) ← (A)
MOVX @DPTR,A
Bytes: 1
Cycles: 2
Encoding: _{1 1 1 1 0 0 0 0}
Operation: MOVX
((DPTR)) ← (A)
MUL AB
Function: Multiply
Description: MUL AB multiplies the unsigned eight-bit integers in the Accumulator and register B. The low-
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.
Bytes: 1
Cycles: 4
Encoding: _{1 0 1 0 0 1 0 0}
Operation: MUL
(A)7-0 ← (A) x (B)
(B)15-8
© Philips Electronics N.V. 2005
Page 117 of 132