Texas Instruments TMS320C67X/C67X+ DSP - Manual (Page 285)

Multiply Signed 16 LSB x Signed 16 MSB With Left Shift and Saturation SMPYLH
3-225 Instruction Set SPRU733
Example SMPYLH .M1 A1,A2,A3
Before instruction 2 cycles after instruction
A1 0000 8000h −32768 ‡ A1 0000 8000h
A2 8000 0000h −32768 † A2 8000 0000h
A3 xxxx xxxxh A3 7FFF FFFFh 2147483647
CSR 0001 0100h CSR 0001 0300h Saturated
† Signed 16-MSB integer
‡ Signed 16-LSB integer