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SH7751 Group, SH7751R Group
Section 14 Direct Memory Access Controller (DMAC)
R01UH0457EJ0301 Rev. 3.01
Page 549 of 1128
Sep 24, 2013
14.3.6
Ending DMA Transfer
The conditions for ending DMA transfer are different for ending on individual channels and for
ending on all channels together. Except for the case where transfer ends when the value in the
DMA transfer count register (DMATCR) reaches 0, the following conditions apply to ending
transfer.
1. Cycle Steal Mode (External Request, On-Chip Peripheral Module Request, Auto-Request)
When a transfer end condition is satisfied, acceptance of DMAC transfer requests is
suspended. The DMAC completes transfer for the transfer requests accepted up to the point at
which the transfer end condition was satisfied, then stops.
In cycle steal mode, the operation is the same for both edge and level transfer request
detection.
2. Burst Mode, Edge Detection (External Request, On-Chip Peripheral Module Request, Auto-
Request)
The delay between the point at which a transfer end condition is satisfied and the point at
which the DMAC actually stops is the same as in cycle steal mode. In burst mode with edge
detection, only the first transfer request activates the DMAC, but the timing of stop request
(DE = 0 in CHCR, DME = 0 in DMAOR) sampling is the same as the transfer request
sampling timing shown in 4 and 5 under Operation in section 14.3.5, Number of Bus Cycle
States and
DREQ
Pin Sampling Timing. Therefore, a transfer request is regarded as having
been issued until a stop request is detected, and the corresponding processing is executed
before the DMAC stops.
3. Burst Mode, Level Detection (External Request)
The delay between the point at which a transfer end condition is satisfied and the point at
which the DMAC actually stops is the same as in cycle steal mode. As in the case of burst
mode with edge detection, the timing of stop request (DE = 0 in CHCR, DME = 0 in DMAOR)
sampling is the same as the transfer request sampling timing shown in 2 and 3 under Operation
in section 14.3.5, Number of Bus Cycle States and
DREQ
Pin Sampling Timing. Therefore, a
transfer request is regarded as having been issued until a stop request is detected, and the
corresponding processing is executed before the DMAC stops.
4. Transfer Suspension Bus Timing
Transfer suspension is executed on completion of processing for one transfer unit. In dual
address mode transfer, write cycle processing is executed even if a transfer end condition is
satisfied during the read cycle, and the transfers covered in 1, 2, and 3 above are also executed
before operation is suspended.
Содержание SH7751 Group
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Страница 226: ...Section 5 Exceptions SH7751 Group SH7751R Group Page 172 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 264: ...Section 7 Instruction Set SH7751 Group SH7751R Group Page 210 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 320: ...Section 9 Power Down Modes SH7751 Group SH7751R Group Page 266 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 344: ...Section 10 Clock Oscillation Circuits SH7751 Group SH7751R Group Page 290 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 388: ...Section 12 Timer Unit TMU SH7751 Group SH7751R Group Page 334 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 800: ...Section 17 Smart Card Interface SH7751 Group SH7751R Group Page 746 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 848: ...Section 19 Interrupt Controller INTC SH7751 Group SH7751R Group Page 794 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 876: ...Section 20 User Break Controller UBC SH7751 Group SH7751R Group Page 822 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 1036: ...Section 22 PCI Controller PCIC SH7751 Group SH7751R Group Page 982 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
Страница 1152: ...Appendix C Mode Pin Settings SH7751 Group SH7751R Group Page 1098 of 1128 R01UH0457EJ0301 Rev 3 01 Sep 24 2013 ...
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