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)
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