Texas Instruments TMS320C67X/C67X+ DSP - Manual (Page 204)

MPY Multiply Signed 16 LSB x Signed 16 LSB
3-144 Instruction Set SPRU733
Example 1 MPY .M1 A1,A2,A3
Before instruction 2 cycles after instruction
A1 0000 0123h 291 † A1 0000 0123h
A2 01E0 FA81h −1407 † A2 01E0 FA81h
A3 xxxx xxxxh A3 FFF9 C0A3 −409437
† Signed 16-LSB integer
Example 2 MPY .M1 13,A1,A2
Before instruction 2 cycles after instruction
A1 3497 FFF3h −13 † A1 3497 FFF3h
A2 xxxx xxxxh A2 FFFF FF57h −163
† Signed 16-LSB integer