Infineon Technologies C166S V2 User Manual page 345

CoMACMRsu
Group
Syntax
Source Operand(s)
Destination Operand(s)
Operation
(tmp) ← ((op1)) * ((op2))
(ACC) ← (tmp) - (ACC) + 00 0000 8000h
(MAL) ← 0
((IDXi(-*))) ← ((IDXi))
Description
Multiplies the two signed and unsigned 16-bit source operands op1 and op2,
respectively. The resulting signed 32-bit product is first sign-extended; then, the 40-bit
ACC register contents are subtracted from the result before being stored in the 40-bit
ACC register. Finally, the result is 2s complement rounded before being stored in the
40-bit ACC register. The MAL register is cleared. 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 & Round
Multiply/Multiply-Accumulate Instructions
CoMACMRsu op1, op2, rnd
op1, op2 → WORD
ACC → 40-bit signed value
ME MSV
* *
Detailed Instruction Description
MC MZ
* *
8-345
User Manual
C166S V2
CoMACMRsu
MN Sat.
* yes
V 1.7, 2001-01