
Section 13 Direct Memory Access Controller (DMAC)
Rev. 4.00 Sep. 14, 2005 Page 430 of 982
REJ09B0023-0400
These are selected by the PR1 and the PR0 bits in the DMA operation register (DMAOR).
Round-Robin Mode: Each time one word, byte, or longword 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 13.3. The priority of the
round-robin mode is CH0 > CH1 > CH2 > CH3 immediately after reset.
When the round-robin mode has been specified, do not concurrently specify cycle steal mode and
burst mode as the bus modes of any two channels.
CH1
>
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
Priority order
afrer transfer
Priority order
afrer 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 0 and 3, 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
afrer transfer
Priority order
afrer transfer
Priority order
afrer transfer
Post-transfer priority order
when there is an
immediate transfer
request to channel 5 only
(2) When channel 1 transfers
(3) When channel 2 transfers
(4) When channel 3 transfers
Figure 13.3 Round-Robin Mode
Содержание HD6417641
Страница 2: ...Rev 4 00 Sep 14 2005 Page ii of l...
Страница 7: ...Rev 4 00 Sep 14 2005 Page vii of l...
Страница 11: ...Rev 4 00 Sep 14 2005 Page xi of l USB Universal serial bus WDT Watch dog timer...
Страница 12: ...Rev 4 00 Sep 14 2005 Page xii of l...
Страница 28: ...Rev 4 00 Sep 14 2005 Page xxviii of l...
Страница 204: ...Section 4 Clock Pulse Generator CPG Rev 4 00 Sep 14 2005 Page 154 of 982 REJ09B0023 0400...
Страница 212: ...Section 5 Watchdog Timer WDT Rev 4 00 Sep 14 2005 Page 162 of 982 REJ09B0023 0400...
Страница 228: ...Section 6 Power Down Modes Rev 4 00 Sep 14 2005 Page 178 of 982 REJ09B0023 0400...
Страница 246: ...Section 8 X Y Memory Rev 4 00 Sep 14 2005 Page 196 of 982 REJ09B0023 0400...
Страница 318: ...Section 11 User Break Controller UBC Rev 4 00 Sep 14 2005 Page 268 of 982 REJ09B0023 0400...
Страница 454: ...Section 12 Bus State Controller BSC Rev 4 00 Sep 14 2005 Page 404 of 982 REJ09B0023 0400...
Страница 500: ...Section 13 Direct Memory Access Controller DMAC Rev 4 00 Sep 14 2005 Page 450 of 982 REJ09B0023 0400...
Страница 504: ...Section 14 U Memory Rev 4 00 Sep 14 2005 Page 454 of 982 REJ09B0023 0400...
Страница 566: ...Section 17 Compare Match Timer CMT Rev 4 00 Sep 14 2005 Page 516 of 982 REJ09B0023 0400...
Страница 734: ...Section 18 Multi Function Timer Pulse Unit MTU Rev 4 00 Sep 14 2005 Page 684 of 982 REJ09B0023 0400...
Страница 868: ...Section 21 A D Converter Rev 4 00 Sep 14 2005 Page 818 of 982 REJ09B0023 0400...
Страница 914: ...Section 23 I O Ports Rev 4 00 Sep 14 2005 Page 864 of 982 REJ09B0023 0400...
Страница 956: ...Section 24 List of Registers Rev 4 00 Sep 14 2005 Page 906 of 982 REJ09B0023 0400...
Страница 1016: ...Section 25 Electrical Characteristics Rev 4 00 Sep 14 2005 Page 966 of 982 REJ09B0023 0400...
Страница 1024: ...Appendix Rev 4 00 Sep 14 2005 Page 974 of 982 REJ09B0023 0400...
Страница 1032: ...Rev 4 00 Sep 14 2005 Page 982 of 982 REJ09B0023 0400 X X Y data addressing 52 X Y memory 193...
Страница 1035: ......
Страница 1036: ...SH7641 Hardware Manual...