209
CK
DREQ
DACK
Bus cycle
Tc
Tr
Tp
Tc
CPU
DMAC(R)
DMAC (R)
Tc
Tr
Tp
Tc
CPU
CPU
DMAC
(W)
CPU
DMAC
(W)
CPU
DMAC (R): DMAC read cycle
DMAC (W): DMAC write cycle
Note:
When
DREQ
is negated at the fourth state of the DMAC cycle, the next DMA transfer will
be executed because the sampling is performed at the second state of the DMAC cycle.
Figure 9.20
DREQ
Sampling Timing in Cycle-Steal Mode (Output with
DREQ
Level
Detection and DACK Active-Low) (Dual Address Mode, Bus Cycle = DRAM Bus Cycle
(Long Pitch Normal Mode))
CK
DREQ
DACK
Bus cycle
T3
T2
T1
T4
CPU
CPU
CPU
DMAC
CPU
CPU
T3
T2
T1
T4
DMAC
Note:
When
DREQ
is negated at the fourth state of the DMAC cycle, the next DMA transfer will
be executed because the sampling is performed at the second state of the DMAC cycle.
Figure 9.21
DREQ
Sampling Timing in Cycle-Steal Mode (Output with
DREQ
Level
Detection and DACK Active-Low) (Single Address Mode, Bus Cycle = Address/Data
Multiplex I/O Bus Cycle)
Summary of Contents for HD6417032
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Page 525: ...490 CK RAS CAS TRp TRc TRcc tRASD1 tRASD2 tCASD3 tCASD2 TRr tCSR Figure 20 18 Self Refresh ...
Page 578: ...543 CK RAS CAS TRp TRc TRcc tRASD1 tRASD2 tCASD3 tCASD2 TRr tCSR Figure 20 62 Self Refresh ...
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