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Section 13 Direct Memory Access Controller (DMAC)
Rev. 4.00 Sep. 14, 2005 Page 438 of 982
REJ09B0023-0400
DREQ
CPU
CPU
Bus cycle
CPU
DMAC DMAC
CPU
CPU
DMAC DMAC
CPU
Read/Write
Read/Write
More than 16 or 64B
φ
(change by the CPU's condition of using bus)
Figure 13.10 Example of DMA Transfer in Cycle Steal Intermittent Mode
(Dual Address,
DREQ
Low Level Detection)
2. Burst Mode
Once the bus mastership is obtained, the transfer is performed continuously until the transfer
end condition is satisfied. In the external request mode with low level detection of the
DREQ
pin, however, when the
DREQ
pin is driven high, the bus passes to the other bus master after
the DMAC transfer request that has already been accepted ends, even if the transfer end
conditions have not been satisfied.
The burst mode cannot be used for other than CMT0, CMT1, and MTU0 to MTU4 when the
on-chip peripheral module is the transfer request source. Figure 13.11 shows DMA transfer
timing in the burst mode.
CPU
CPU
CPU
DMAC DMAC DMAC
DMAC
DMAC DMAC
CPU
DREQ
Bus cycle
Read
Read
Read
Write
Write
Write
Figure 13.11 DMA Transfer Example in the Burst Mode
(Dual Address,
DREQ
Low Level Detection)
Relationship between Request Modes and Bus Modes by DMA Transfer Category: Table
13.9 shows the relationship between request modes and bus modes by DMA transfer category.
Содержание HD6417641
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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...
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