Renesas SH7641 - Manual (Page 150)

Section 3 DSP Operation
Rev. 4.00 Sep. 14, 2005 Page 100 of 982
REJ09B0023-0400
Table 3.1 Variation of ALU Fixed-Point Operations
Mnemonic Function Source 1 Source 2 Destination
PADD Addition Sx Sy Dz (Du)
PSUB Subtraction Sx Sy Dz (Du)
PADDC Addition with carry Sx Sy Dz
PSUBC Subtraction with borrow Sx Sy Dz
PCMP Comparison Sx Sy —
PCOPY Data copy Sx All 0 Dz
All 0 Sy Dz
PABS Absolute Sx All 0 Dz
All 0 Sy Dz
PNEG Negation Sx All 0 Dz
All 0 Sy Dz
PCLR Clear All 0 All 0 Dz
Table 3.2 Correspondence between Operands and Registers
Register Sx Sy Dz Du
A0 Yes — Yes Yes
A1 Yes — Yes Yes
M0 — Yes Yes —
M1 — Yes Yes —
X0 Yes — Yes Yes
X1 Yes — Yes —
Y0 — Yes Yes Yes
Y1 — Yes Yes —
As shown in figure 3.2, data loaded from the memory at the MA stage, which is programmed at
the same line as the ALU operation, is not used as a source operand for this operation, even
though the destination operand of the data load operation is identical to the source operand of the
ALU operation. In this case, previous operation results are used as the source operands for the
ALU operation, and then updated as the destination operand of the data load operation.