DS89C420 Datasheet, PDF (24/59 Pages) Dallas Semiconductor – Ultra-High-Speed Microcontroller

DS89C420
Figure 5. Non-Page Mode, External Data-Memory Access (Stretch = 0,
CD1:CD2 = 10)
XTAL1
MOVX Instruction
1st Machine Cycle 2nd Machine Cycle
ALE
PSEN
RD WR
Port 0
Port 2
A
MOVX
A
A
MOVX
Instruction
Fetch
INST
A
DATA
A
Memory
Access
Stretch = 0
Figure 6. Non-Page Mode, External Data-Memory Access (Stretch = 1,
CD1:CD2 = 10)
XTAL1
ALE
PSEN
RD WR
Port 0
Port 2
MOVX Instruction
1st Machine Cycle 2nd Machine Cycle 3rd Machine Cycle
A
MOVX
A
A
MOVX
Instruction
Fetch
INST
A
DATA
A
Memory Access
Stretch = 1
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