Texas Instruments TMS320C28x Reference Manual page 392

MPYB ACC,T,#8bit
SYNTAX OPTIONS
MPYB ACC,T,#8bit
Operands ACC
T
#8bit
Description
Flags and Z
Modes
N
Repeat
Example
; Calculate signed using 16-bit multiply:
; Y32 = Y32 + (X16 * 5)
MOV
MPYB
ADDL
0011 0101 CCCC CCCC
Accumulator register
Multiplicand register
8-bit immediate constant value
Multiply the signed 16-bit content of the T register by the unsigned 8-bit
constant value zero extended and store the result in the ACC register:
ACC = signed T * 0:8bit
After the operation, the Z flag is set if the ACC 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.
T,@X16 ; T = X16
ACC,T,#5 ; ACC = T * 5
@Y32,ACC ; Y32 = Y32 + ACC
Multiply by 8-bit Constant
OPCODE OBJMODE
MPYB ACC,T,#8bit
RPT CYC
X − 1
6-235