Section 9 Direct Memory Access Controller (DMAC)
Rev. 5.00 May 29, 2006 page 298 of 698
REJ09B0146-0500
9.6
Examples of Use
9.6.1
Example of DMA Transfer between A/D Converter and External Memory
(Address Reload on)
In this example, DMA transfer is performed between the on-chip A/D converter (transfer source)
and the external memory (transfer destination) with address reload function on. Table 9.6 shows
the transfer conditions and register settings.
Table 9.6
Transfer Conditions and Register Settings for Transfer between On-Chip A/D
Converter and External Memory
Transfer Conditions
Register
Setting
Transfer source: on-chip A/D converter
SAR_2
H'04000080
Transfer destination: external memory
DAR_2
H'00400000
Number of transfers: 128 (reloading 32 times)
DMATCR_2
H'00000080
Transfer source address: incremented
Transfer destination address: decremented
Transfer request source: A/D converter
Bus mode: burst
Transfer unit: long word
Interrupt request generated at end of transfer
CHCR_2
H'00089E35
Channel priority order: 0 > 2 > 3 > 1
DMAOR
H'0101
When the address reload function is on, the values set in SAR_0 to SAR_3 returns to the initially
set value at each four transfers. In this example, when an interrupt request is generated from A/D
converter, longword data is read from the register in address H'04000080 in A/D converter, and it
is written to external memory address H'00400000. Since longword data has been transferred, the
values in SAR_2 and DAR_2 are H'04000084 and H'003FFFFC, respectively. The bus right is
maintained and data transfers are successively performed because this transfer is in the burst
mode.
After four transfers end, fifth and sixth transfers are performed if the address reload function is off,
and the value in SAR_2 is incremented from H'0400008C, H'04000090, H'04000094,.... If the
address reload function is on, the DMA transfer stops after the fourth transfer ends, the bus request
signal to the CPU is cleared. At this time, the value stored in SAR_2 is not incremented from
H'0400008C to H'04000090, but returns to the initially set value H'04000080. The value in
Содержание SH7706 Series
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Страница 160: ...Section 5 Cache Rev 5 00 May 29 2006 page 112 of 698 REJ09B0146 0500 ...
Страница 370: ...Section 11 Watchdog Timer WDT Rev 5 00 May 29 2006 page 322 of 698 REJ09B0146 0500 ...
Страница 532: ...Section 16 Serial Communication Interface with FIFO SCIF Rev 5 00 May 29 2006 page 484 of 698 REJ09B0146 0500 ...
Страница 554: ...Section 17 Pin Function Controller PFC Rev 5 00 May 29 2006 page 506 of 698 REJ09B0146 0500 ...
Страница 576: ...Section 18 I O Ports Rev 5 00 May 29 2006 page 528 of 698 REJ09B0146 0500 ...
Страница 614: ...Section 21 User Debugging Interface H UDI Rev 5 00 May 29 2006 page 566 of 698 REJ09B0146 0500 ...
Страница 746: ...Index Rev 5 00 May 29 2006 page 698 of 698 REJ09B0146 0500 ...
Страница 749: ...SH7706 Group Hardware Manual ...