Renesas SH7641 - Manual (Page 190)

Section 3 DSP Operation
Rev. 4.00 Sep. 14, 2005 Page 140 of 982
REJ09B0023-0400
31
15 1
0
R4 [Ax]
R5 [Ax]
ABx
XAB 16-bit
X_MEM
X R/W
Y_MEM
Y R/W
YAB 16-bit
XDB
YDB
16-bit
16-bit
X data
memory
4 kbytes
31
15 1
0
R6 [Ay]
R7 [Ay]
ABy
Y data
memory
4 kbytes
X_MEM and Y_MEM:
Select X and Y data memory
Instruction code for X
data-transfer operation
Instruction code for Y
data-transfer operation
Control
for X memory
Control
for Y memory
Input/output
control for
DSP data
registers
X0/X1, A0/A1 Input/output
control for
DSP data
registers
Y0/Y1, A0/A1
Figure 3.22 Load/Store Control for X and Y Data-Transfer Instructions
Control for X Memory:
if ( !Nop ) {
X_MEM=1; XAB=ABx;
if ( load operation ) {
Dx[31:16]=XDB;
Dx[15:0]=0x0000; / * Dx is X0 or X1 */
}
else XDB = Dx[31:16]; / * Dx is A0 or A1 */
}
else { X_MEM=0; XAB=0x000; }
The conditional execution based on the DC flag in DSR cannot control any MOVX/MOVY
instructions.