Texas Instruments TMS320C28x Reference Manual page 462

QMPYL ACC,XT,loc32
SYNTAX OPTIONS
QMPYL ACC,XT,loc32
Operands P
XT
ACC
Description
Flags and
Z
Modes
N
Repeat
Example
; Calculate signed result: Y64 = M32*X32
MOVL
IMPYL
QMPYL
MOVL
MOVL
0101 0110 0110 0011
0000 0000 LLLL LLLL
Product register
Multiplicand register
Accumulator register
Multiply the signed 32-bit content of the XT register by the signed 32-bit
content of the location pointed to by the "loc32" addressing mode and store
the upper 32−bits of the 64-bit result (a Q30 number) in the ACC register:
ACC = (signed XT * signed [loc32]) >> 32;
After the operation, the Z flag is set if the ACC value is zero, else Z is cleared.
After the operation, the N flag is set if bit 31 of the ACC is 1, else N is cleared.
This instruction is not repeatable. If this instruction follows the RPT
instruction, it resets the repeat counter (RPTC) and executes only once.
XT,@M32
P,XT,@X32
ACC,XT,@X32
@Y64+0,P
@Y64+2,ACC
Signed 32 X 32-bit Multiply (Upper Half)
OPCODE
; XT = M32
; P = low 32−bits of (M32*X32)
; ACC = high 32−bits of (M32*X32)
; Store result into Y64
QMPYL ACC,XT,loc32
OBJMODE RPT CYC
1 − 2
6-305