Section 14 Direct Memory Access Controller (DMAC)
SH7751 Group, SH7751R Group
Page 548 of 1128
R01UH0457EJ0301 Rev. 3.01
Sep 24, 2013
DRAK0
: DREQ samplin
g
and determination of channel priority
DREQ1
DREQ0
(level
detection)
DACK0
Bus cycle
A[25:0]
CKIO
D[31:0]
1st
acceptance
CPU
CPU
D1
D6
D8
Asserted 2 cycles before
start of bus cycle
Asserted 2 cycles before
start of bus cycle
Asserted 2 cycles before
start of bus cycle
2nd
acceptance
3rd
acceptance
DMAC-1
DMAC-2
DMAC-3
Destination
address
Destination
address
Destination
address
D1
D6
D8
D1
D6
D7
D8
D7
D7
Le
g
end:
Figure 14.22 Single Address Mode/Burst Mode
External Bus
→
External Bus/
DREQ
(Level Detection)/32-Byte Block Transfer
(Bus Width: 32 Bits, SDRAM: Row Hit Write)