DS89C440 Maxim, DS89C440 Datasheet - Page 28

• Manufacturer Part Number: DS89C440
• Description: The DS89C430 and DS89C450 offer the highest performance available in 8051-compatible microcontrollers
• Manufacturer: Maxim

Figure 8. Nonpage Mode, External Data Memory Access (Stretch = 0, CD1:CD2 = 10)
Figure 9. Nonpage Mode, External Data Memory Access (Stretch = 1, CD1:CD2 = 10)
XTAL1
RD/WR
XTAL1
RD/WR
Port 0
Port 2
Port 0
Port 2
ALE
PSEN
PSEN
ALE
MOVX
Instruction
Fetch
MOVX
Instruction
Fetch
A
A
A
A
MOVX
MOVX
1st Machine Cycle
1st Machine Cycle
A
A
MOVX Instruction
INST
INST
MOVX Instruction
2nd Machine Cycle
2nd Machine Cycle
DS89C430/DS89C450 Ultra-High-Speed Flash Microcontrollers
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Memory
Access
Stretch = 0
A
A
A
A
Memory Access
Stretch = 1
DATA
DATA
3rd Machine Cycle