Section 11 Direct Memory Access Controller (DMAC)
Rev. 2.00 Mar 09, 2006 page 499 of 906
REJ09B0292-0200
Acknowledge Signal Output when External Memory Is Set as Synchronous DRAM:
When
external memory is set as synchronous DRAM, DACKn output becomes valid simultaneously
with the start of the DMA address, and becomes invalid when the address output ends.
When external memory is set as synchronous DRAM auto-precharge and AM = 0, the
acknowledge signal is output across the row address, read command, wait and read address of the
DMAC read (figure 11.19). Since the synchronous DRAM read has only burst mode, during a
single read an invalid address is output; the acknowledge signal, however, is output on the same
timing (figure 11.20). At this time, the acknowledge signal is extended until the write address is
output after the invalid read. A synchronous DRAM burst read is performed in the case of 16-byte
transfer. As 16-byte transfer is enabled only in auto-request mode and in external request mode
with edge detection, when using on-chip peripheral module requests or external request mode with
level detection, byte, word, or longword should be set as the transfer unit. Operation is not
guaranteed if a 16-byte unit is set when using on-chip peripheral module requests or external
request mode with level detection. When AM = 1, the acknowledge signal is output across the row
address and column address of the DMAC write (figure 11.21).
Clock
DACKn
(Active high)
Address
bus
CPU
DMAC read (basic timing)
Row
address
Read 1
Read 2
Read 3
Read 4
Read
command
Figure 11.19 DACKn Output in Synchronous DRAM Burst Read
(Auto-Precharge, AM = 0)
Содержание SH7616
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Страница 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Страница 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Страница 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Страница 662: ...Section 14 Serial Communication Interface with FIFO SCIF Rev 2 00 Mar 09 2006 page 636 of 906 REJ09B0292 0200 ...
Страница 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Страница 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Страница 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Страница 935: ...SH7616 Hardware Manual ...