Infineon Technologies C166S V2 User Manual page 343

CoMACMR
Group
Syntax
Source Operand(s)
Destination Operand(s)
Operation
IF (MP = 1) THEN
ELSE
END IF
((IDXi(-*))) ← ((IDXi))
Description
Multiplies the two signed 16-bit source operands op1 and op2. The resulting signed
32-bit product is first sign-extended; then, if the MP flag is set, it is one-bit left shifted;
and next, the 40-bit ACC register contents are subtracted from the result before being
stored in the 40-bit ACC register. In parallel to the arithmetic operation and to the two
parallel reads, the data pointed to by IDXi overwrites another data located in memory
(DPRAM). The address of the overwritten data depends on the operation executed on
IDXi.
MAC Flags
MV MSL
* *
MV Set if an arithmetic underflow occurred, i.e. the result cannot be
represented in the 40-bit data type. Cleared otherwise.
MSL Set if the contents of ACC is automatically saturated. Not affected
otherwise.
ME Set if the MAE is used. Cleared otherwise.
MSV Set if an arithmetic underflow occurred. Not affected otherwise.
MC Set if a borrow is generated. Cleared otherwise.
MZ Set if result equals zero. Cleared otherwise.
MN Set if the most significant bit of the result is set. Cleared otherwise.
User Manual
Multiply-Accumulate & Move
Multiply/Multiply-Accumulate Instructions
CoMACMR op1, op2
op1, op2 → WORD
ACC → 40-bit signed value
(tmp) ← (((op1)) * ((op2))) <<1
(ACC) ← (tmp) - (ACC)
(tmp) ← ((op1)) * ((op2))
(ACC) ← (tmp) - (ACC)
ME MSV
* *
Detailed Instruction Description
MC MZ
* *
8-343
User Manual
C166S V2
CoMACMR
MN Sat.
* yes
V 1.7, 2001-01