DS80C310

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AC ELECTRICAL CHARACTERISTICS

25 MHz

VARIABLE CLOCK

PARAMETER

SYMBOL

MIN

MAX

MIN

MAX

NOTES

Oscillator Freq. (Ext. Osc.)

(Ext. Crystal)

0

1

33

33

0

1

33

33

MHz

ALe Pulse Width

40

ns

Port 0 Address Valid to ALE Low

10

ns

Address Hold after ALE Low

10

ns

ALE Low to Valid Instruction In

56

ns

ALE Low to

PSEN Low

10

ns

PSEN Pulse Width

55

ns

PSEN Low to Valid Instr. In

41

ns

Input Instruction Hold after

PSEN

0

0

ns

Input Instruction Float after

PSEN

26

ns

Port 0 Address to Valid Instr. In

71

ns

Port 2 Address to Valid Instr. In

81

ns

PSEN Low to Address Float

0

0

ns

NOTES FOR AC ELECTRICAL CHARACTERISTICS

All parameters apply to both commercial and ind ustrial temperature range operation unless otherwise

noted. All signals characterized with load capacitance of 80 pF except Port 0, ALE,

PSEN , and WR with

100 pF. Interfacing to memory devices with float times (turn off times) over 25 ns may cause contention.

This will not damage the parts, but will cause an increase in operating current. Specifications assume a

50% duty cycle for the oscillator. Port 2 and ALE timing will change in relation to duty cycle variation.