Renesas SH7641 User Manual
Page 188
Section 3 DSP Operation
Rev. 4.00 Sep. 14, 2005 Page 138 of 982
REJ09B0023-0400
Addressing Instructions in Execution Stage: Address instructions, including modulo addressing,
are executed in the execution stage of the pipeline. Behavior of the DSP data addressing in the
execution stage is shown below.
if ( Operation is MOVX.W MOVY.W ) {
ABx=Ax; ABy=Ay;
/
* Memory access cycle uses ABx and ABy. The addresses to be used have
not been updated.
*/
/
* Ax is one of R4,5 */
if { DMX==0 || ( DMX==1 && DMY==1 )} Ax = Ax+(+2 or R8[Ix] or +0);
/
* Inc,Index,Not-Update */
else if (! not-update) Ax=modulo( Ax, (+2 or R8[Ix]) );
/
* Ay is one of R6,7 */
if ( DMY==0 ) Ay=Ay+(+2 or R9[Iy] or +0); /
* Inc,Index,Not-Update */
else if (! not-update) Ay=modulo( Ay, (+2 or R9[Iy]) );
}
else if ( Operation is MOVS.W or MOVS.L ) {
if ( Addressing is Nop, Inc, Add-index-reg ) {
MAB=As;
/
* Memory access cycle uses MAB. The address to be used has not been
updated.
*/
/
* As is one of R2 to R5 */
As = As+(+2 or +4 or R8[Is] or +0); /
* Inc,Index,Not-Update */
else { /
* Decrement, Pre-update */
/
* As is one of R2 to R5 */
As=As+(-2 or -4);
MAB=As;
/
* Memory access cycle uses MAB. The address to be used has been
updated.
*/
}