Infineon Technologies C166S V2 User Manual page 365

CoMACMus-
Group
Syntax
Source Operand(s)
Destination Operand(s)
Operation
(tmp) ← ((op1)) * ((op2))
(ACC) ← (ACC) - (tmp)
((IDXi(-*))) ← ((IDXi))
Description
Multiplies the two unsigned and signed 16-bit source operands op1 and op2,
respectively. The resulting signed 32-bit product is first sign-extended; then, it is
subtracted from the 40-bit ACC register contents 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.
Encoding
Mnemonic
CoMACMus- [IDXi*], [Rw
User Manual
Multiply-Accumulate & Move
Multiply/Multiply-Accumulate Instructions
CoMACMus- op1, op2
op1, op2 → WORD
ACC → 40-bit signed value
ME MSV
* *
*]
m
Detailed Instruction Description
MC MZ
* *
Format
93 Xm A8 rrr0:0qqq
8-365
User Manual
C166S V2
CoMACMus-
MN Sat.
* yes
Bytes
4
V 1.7, 2001-01