TSC80251 TEMIC [TEMIC Semiconductors], TSC80251 Datasheet - Page 172

• Manufacturer Part Number: TSC80251
• Manufacturer: TEMIC [TEMIC Semiconductors]

Rev. C – May 7, 1999
MUL <dest>,<src>
Function:
Multiply
Description:
Multiplies the unsigned integer in the source register with the unsigned integer in the destination register. Only register
addressing is allowed.
For 8–bit operands, the result is 16 bits. The most significant byte of the result is stored in the low byte of the word
where the destination register resides. The least significant byte is stored in the following byte register. The OV flag
is set if the product is greater than 255 (0FFh); otherwise it is cleared.
For 16–bit operands, the result is 32 bits. The most significant word is stored in the low word of the the dword where
the destination register resides. The least significant word is stored in the following word register. In this operation,
the OV flag is set if the product is greater than 0FFFFh, otherwise it is cleared. The CY flag is always cleared. The
N flag is set when the MSB of the result is set. The Z flag is set when the result is zero.
Example :
Register R1 contains 80 (50h or 10010000B) and register R0 contains 160 (0A0h or 10010000B). After executing the
instruction MUL R1,R0 which gives the product 12800 (3200h), register R0 contains 32h (00110010B), register R1
contains 00h, the OV flag is set and the CY flag is clear.
MUL Rmd,Rms
[Encoding]
MUL WRjd,WRjs
[Encoding]
FLAGS :
Hex Code in:
Binary Mode = [A5][Encoding]
Source Mode = [Encoding]
1010
1010
CY
0
1100
1101
AC
_
ssss
tttt
OV
TTTT
SSSS
Operation:
MUL (8–bit operands)
if <dest> md = 0, 2, 4, .., 14
Rmd
Rmd+1
if <dest> md = 1, 3, 5, .., 15
Rmd-1
Rmd
high byte of the Rmd x Rms
low byte of the Rmd x Rms
high byte of the Rmd x Rms
low byte of the Rmd x Rms
N
TSC80251
Z
5.127