Motorola DSP56800 Manual page 361

MPYR
Instruction Fields:
Operation
MPYR
Data ALU Operation
Operation
MPYR
Data ALU
Operation
Operation Registers
MPYR
(F = A or B)
Timing:
2 + mv oscillator clock cycles for MPYR instructions with a parallel move
Refer to previous table for MPYR instructions without a parallel move
Memory:
1 program word for MPYR instructions with a parallel move
Refer to previous table for MPYR instructions without a parallel move
Signed Multiply and Round
Operands C
(±)Y1,X0,FDD 2
(±)Y0,X0,FDD
(±)Y1,Y0,FDD
(±)Y0,Y0,FDD
(±)A1,Y0,FDD
(±)B1,Y1,FDD
Registers
Y1,B1,F
Y0,Y0,F
Y0,A1,F
X0,Y0,F
X0,Y1,F
Y0,Y1,F
(F = A or B)
First and Second Memory
Read1
Y0,X0,F X:(R0)+
Y1,X0,F X:(R0)+N
Y1,Y0,F
X:(R1)+
X:(R1)+N
Instruction Set Details
W
1 Fractional multiply where one operand is optionally
negated before multiplication; result is rounded
Note: Assembler also accepts first two operands
when they are specified in opposite order
Parallel Memory Read or Write
Memory Access Source or Destination
X:(Rn)+
X:(Rn)+N
Reads
Read2 Destination1
X:(R3)+
X:(R3)-
Valid
destinations
for Read1
MPYR
Comments
X0
Y1
Y0
A
B
A1
B1
Destinations for Memory
Reads
Destination2
Y0 X0
Y1 X0
Valid
destinations
for Read2
A-131