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SH7751 Group, SH7751R Group
Section 14 Direct Memory Access Controller (DMAC)
R01UH0457EJ0301 Rev. 3.01
Page 593 of 1128
Sep 24, 2013
14.7.5
DMA Operation Register (DMAOR)
Bit:
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
— — — — — — — — — — — — — — — —
Initial
value:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
R/W:
R R R R R R R R R R R R R R R R
Bit:
15
14
13
12
11
10 9 8 7 6 5 4 3 2 1 0
DDT
DBL
— — — —
PR1 PR0
— — — — — AE
NMIF
DME
Initial
value:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
R/W:
R/W
R/W
R R R R
R/W R/W
R R R R R
R/(W)
R/(W)
R/W
DMAOR is a 32-bit readable/writable register that specifies the DMAC transfer mode.
DMAOR is initialized to H'00000000 by a power-on or manual reset. They retain their values in
standby mode and deep sleep mode.
Bits 31 to 16—Reserved:
These bits are always read as 0, and should only be written with 0.
Bit 15—On-Demand Data Transfer (DDT):
Specifies on-demand data transfer mode. For
details of the settings, see the description of the DDT bit in section 14.2.5, DMA Operation
Register (DMAOR).
Bit 14
⎯
Number of DDT-Mode Channels (DBL):
Selects the number of channels that are able
to accept external requests in DDT mode.
Bit 14: DBL
Description
0
Four DDT-mode channels
(Initial value)
1
Eight DDT-mode channels
Note: When DMAOR.DBL = 0, channels 4 to 7 do not accept external requests.
When DMAOR.DBL = 1, one channel can be selected from among channels 0
−
7 by the
combination of DTR.SZ and DTR.ID in the DTR format (see figure 14.54). Table 14.15 shows the
channel selection by DTR format in the DDT mode.