14. Direct Memory Access Controller (DMAC)
Rev.1.00 Jan. 10, 2008 Page 720 of 1658
REJ09B0261-0100
This function enables sequential voice compression by switching a storing buffer for data received
consequentially and a data buffer for processing signals alternately.
14.4.6
Reload Mode Transfer
In a reload mode transfer, according to the settings of bits RPT in CHCR, the value set in
SARB/DARB is reloaded to SAR/DAR at each transfer set in bits 23 to 16 and bits 7 to 0 in
TCRB, and the transfer is repeated until TCR is 0 without specifying the transfer again. This
function is effective when data transfer with specific area is repeatedly executed. Figure 14.12
shows the operation of reload mode transfer.
In reload mode, TCRB is used as a reload counter. See section 14.3.6, DMA Transfer Count
Registers B0 to B3, B6 to B9 (TCRB0 to TCRB3, TCRB6 to TCRB9), and set TCRB.
Figure 14.12 shows an example of reload mode settings.
Re
g
ister settin
g
s
Set the source address in SAR (the data written to SAR is also written to SARB.)
Set the destination address in DAR
Set H'0000000C to TCR (12 transfers)
Set H'00040004 to TCRB (Reloadin
g
for every four transfers)
Set CHCR as follows.
RPT (bits 27 to 25) = B'111: Reload mode (Reloadin
g
SAR)
DM (bits 15 to 14) = B'01: An increase in DAR
SM (bits 13 to 12) = B'01: An increase in SAR
TS (bit 20 and bits 4 to 3) = B'010: Transfer for each (four-byte) lon
g
word
DMA transfer source addresses and DMA transfer destination addresses in the above re
g
ister settin
g
s
Cycle 1:
Source address = SAR
Destination address = DAR
Cycle 2:
Source address = SAR + H'04
Destination address = DAR + H'04
Cycle 3:
Source address = SAR + H'08
Destination address = DAR + H'08
Cycle 4:
Source address = SAR + H'0C
Destination address = DAR + H'0C
Cycle 5:
Source address = SAR
Destination address = DAR + H'10 (reloadin
g
the value of SARB in SAR)
Cycle 6:
Source address = SAR + H'04
Destination address = DAR + H'14
Cycle 7:
Source address = SAR + H'08
Destination address = DAR + H'18
Cycle 8:
Source address = SAR + H'0C
Destination address = DAR + H'1C
Cycle 9: Source address = SAR
Destination address = DAR + H'20 (reloadin
g
the value of SARB in SAR)
Cycle 10: Source address = SAR + H'04
Destination address = DAR + H'24
Cycle 11: Source address = SAR + H'08
Destination address = DAR + H'28
Cycle 12: Source address = SAR + H'0C
Destination address = DAR + H'2C
The relationship between the re
g
ister settin
g
s and the source and destination addresses
of reload mode transfer is described below.
Figure 14.12 Example of Operation Based on Reload Mode Settings
Summary of Contents for SH7781
Page 4: ...Rev 1 00 Jan 10 2008 Page iv of xxx REJ09B0261 0100 ...
Page 74: ...2 Programming Model Rev 1 00 Jan 10 2008 Page 44 of 1658 REJ09B0261 0100 ...
Page 272: ...8 Caches Rev 1 00 Jan 10 2008 Page 242 of 1658 REJ09B0261 0100 ...
Page 376: ...10 Interrupt Controller INTC Rev 1 00 Jan 10 2008 Page 346 of 1658 REJ09B0261 0100 ...
Page 694: ...13 PCI Controller PCIC Rev 1 00 Jan 10 2008 Page 664 of 1658 REJ09B0261 0100 ...
Page 762: ...14 Direct Memory Access Controller DMAC Rev 1 00 Jan 10 2008 Page 732 of 1658 REJ09B0261 0100 ...
Page 788: ...15 Clock Pulse Generator CPG Rev 1 00 Jan 10 2008 Page 758 of 1658 REJ09B0261 0100 ...
Page 828: ...17 Power Down Mode Rev 1 00 Jan 10 2008 Page 798 of 1658 REJ09B0261 0100 ...
Page 846: ...18 Timer Unit TMU Rev 1 00 Jan 10 2008 Page 816 of 1658 REJ09B0261 0100 ...
Page 1292: ...24 Multimedia Card Interface MMCIF Rev 1 00 Jan 10 2008 Page 1262 of 1658 REJ09B0261 0100 ...
Page 1326: ...25 Audio Codec Interface HAC Rev 1 00 Jan 10 2008 Page 1296 of 1658 REJ09B0261 0100 ...
Page 1482: ...28 General Purpose I O Ports GPIO Rev 1 00 Jan 10 2008 Page 1452 of 1658 REJ09B0261 0100 ...
Page 1538: ...30 User Debugging Interface H UDI Rev 1 00 Jan 10 2008 Page 1508 of 1658 REJ09B0261 0100 ...
Page 1688: ...Appendix Rev 1 00 Jan 10 2008 Page 1658 of 1658 REJ09B0261 0100 ...
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