Texas Instruments TMS320C67X/C67X+ DSP - Manual (Page 210)

MPYHL Multiply Signed 16 MSB x Signed 16 LSB
3-150 Instruction Set SPRU733
Example MPYHL .M1 A1,A2,A3
Before instruction 2 cycles after instruction
A1 008A 003Eh 138 † A1 008A 003Eh
A2 21FF 00A7h 167 ‡ A2 21FF 00A7h
A3 xxxx xxxxh A3 0000 5A06h 23046
† Signed 16-MSB integer
‡ Signed 16-LSB integer