Rev. 2.00, 09/03, page 258 of 690
Round-Robin Mode: Each time one byte, word, longword, or 16-byte is transferred on one
channel, the priority order is rotated. The channel on which the transfer was just finished rotates to
the bottom of the priority order. The round-robin mode operation is shown in figure 8.3. The
priority of round-robin mode is CH0 > CH1 > CH2 > CH3 immediately after a reset.
When the round-robin mode is specified, cycle-steal mode and burst mode should not be mixed
among the bus modes for multiple channels.
CH 1
>
CH2
>
CH3
>
CH0
CH0
>
CH1
>
CH2
>
CH3
CH2
>
CH3
>
CH0
>
CH1
CH0
>
CH1
>
CH2
>
CH3
CH2
>
CH3
>
CH0
>
CH1
CH0
>
CH1
>
CH2
>
CH3
CH0
>
CH1
>
CH2
>
CH3
CH3
>
CH0
>
CH1
>
CH2
CH0
>
CH1
>
CH2
>
CH3
(1) When channel 0 transfers
Initial priority order
Initial priority order
Initial priority order
Initial priority order
Priority order
after transfer
Priority order does not change
Channel 2 becomes bottom
priority.
The priority of channels 0 and 1,
which were higher than channel 2,
are also shifted. If immediately
after there is a request to transfer
channel 1 only, channel 1 becomes
bottom priority and the priority of
channels 3 and 0, which were
higher than channel 1, are also
shifted.
Channel 1 becomes bottom
priority.
The priority of channel 0, which
was higher than channel 1, is also
shifted.
Channel 0 becomes bottom
priority
Priority order
after transfer
Priority order
after transfer
Priority order
after transfer
Post-transfer priority order
when there is an
immediate transfer
request to channel 1 only
(2) When channel 1 transfers
(3) When channel 2 transfers
(4) When channel 3 transfers
Figure 8.3 Round-Robin Mode
Содержание SH7705
Страница 2: ......
Страница 46: ...Rev 2 00 09 03 page xlvi of xlvi Appendix Table A 1 I O Port States in Each Processing State 679 ...
Страница 70: ...Rev 2 00 09 03 page 24 of 690 ...
Страница 194: ...Rev 2 00 09 03 page 148 of 690 ...
Страница 284: ...Rev 2 00 09 03 page 238 of 690 ...
Страница 338: ...Rev 2 00 09 03 page 292 of 690 ...
Страница 354: ...Rev 2 00 09 03 page 308 of 690 ...
Страница 374: ...Rev 2 00 09 03 page 328 of 690 ...
Страница 420: ...Rev 2 00 09 03 page 374 of 690 ...
Страница 476: ...Rev 2 00 09 03 page 430 of 690 ...
Страница 482: ...Rev 2 00 09 03 page 436 of 690 ...
Страница 552: ...Rev 2 00 09 03 page 506 of 690 ...
Страница 630: ...Rev 2 00 09 03 page 584 of 690 ...
Страница 739: ...SH7705 Group Hardware Manual REJ09B0082 0200O ...