Texas Instruments TMS320C2XX - Manual (Page 272)

Multiply and Subtract Previous Product MPYS
7-119 Assembly Language Instructions
Cycles for a Repeat (RPT) Execution of an MPYS Instruction
Program
Operand ROM DARAM SARAM External
DARAM n n n n+p
SARAM n n n, n+1 † n+p
External n+nd n+nd n+nd n+1+p+nd
† If the operand and the code are in the same SARAM block
Example 1 MPYS DAT13 ;(DP = 6, PM = 0)
Before Instruction After Instruction
Data Memory Data Memory
30Dh 7h 30Dh 7h
TREG 6h TREG 6h
PREG 36h PREG 2Ah
ACC X 54h ACC 1 1Eh
C C
Example 2 MPYS *,AR5 ;(PM = 0)
Before Instruction After Instruction
ARP 4 ARP 5
AR4 30Dh AR4 30Dh
Data Memory Data Memory
30Dh 7h 30Dh 7h
TREG 6h TREG 6h
PREG 36h PREG 2Ah
ACC X 54h ACC 1 1Eh
C C