
206
CK
DREQ
DACK
Bus cycle
CPU
CPU
CPU
DMAC (R) DMAC (W)
CPU
CPU
CPU
DMAC (R): DMAC read cycle
DMAC (W): DMAC write cycle
Note:
Illustrates the case when DACK is output during the DMAC read cycle.
Figure 9.14
DREQ
Sampling Timing in Cycle-Steal Mode (Output with
DREQ
Level
Detection and DACK Active-Low) (Dual Address Mode, Bus Cycle = 1 State)
CK
DREQ
DACK
Bus cycle
CPU
CPU
CPU
DMAC
CPU
CPU
CPU
CPU
Figure 9.15
DREQ
Sampling Timing in Cycle-Steal Mode (Output with
DREQ
Level
Detection and DACK Active-Low) (Single Address Mode, Bus Cycle = 2 States)
Содержание HD6417032
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Страница 525: ...490 CK RAS CAS TRp TRc TRcc tRASD1 tRASD2 tCASD3 tCASD2 TRr tCSR Figure 20 18 Self Refresh ...
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