DS89C420 Datasheet, PDF (46/59 Pages) Dallas Semiconductor – Ultra-High-Speed Microcontroller

Table 17. AC CHARACTERISTICS
(V_CC = 4.5V to 5.5V; T_A = -40°C to +85°C)*
1 CYCLE
PARAMETER
SYMBOL
PAGE MODE 1
MIN
MAX
System Clock
External Oscillator
External Crystal
1 / tCLCL
0
33
1 / tCLCL
1
33
ALE Pulse Width
tLHLL
0.5tCLCL - 2
+ tSTC3
2 CYCLE
PAGE MODE 1
MIN
MAX
0
33
1
33
tCLCL - 2 +
tSTC3
Port 0 Instruction Address
Valid to ALE Low
tAVLL
Port 2 Instruction Address
Valid to ALE Low
tAVLL2
0.5tCLCL - 4
0.5tCLCL - 4
Port 0 Data AddressValid
to ALE Low
tAVLL3
Program Address Hold
After ALE Low
tLLAX
0.5tCLCL - 8
1.5tCLCL - 8
Address Hold After ALE
Low MOVX Write
tLLAX2
0.5tCLCL - 8
+ tSTC4
1.5tCLCL - 8
+ tSTC4
Address Hold After ALE
Low MOVX Read
tLLAX3
0.5tCLCL - 8
+ tSTC4
1.5tCLCL - 8
+ tSTC4
ALE Low to Valid
Instruction In
tLLIV
4 CYCLE
PAGE MODE 1
MIN
MAX
0
33
1
33
2tCLCL - 4 +
tSTC3
1.5tCLCL - 5
2.5tCLCL - 8
2.5tCLCL - 8
+ tSTC4
2.5tCLCL - 8
+ tSTC4
DS89C420
PAGE MODE 2
MIN
0
MAX
33
1
33
1.5tCLCL - 5 +
tSTC3
NON-PAGE MODE
MIN
0
MAX
33
1
33
1.5tCLCL - 5 +
tSTC3
tCLCL - 2
0.5tCLCL - 2
UNITS NOTES
MHz
1
ns
2
ns
0.5tCLCL - 2
tCLCL - 2
ns
tCLCL - 2 +
0.5tCLCL - 2 +
ns
tSTC3
tSTC3
0.5tCLCL - 8
0.5tCLCL - 8
ns
0.5tCLCL - 8 +
0.5tCLCL - 8 +
ns
tSTC4
tSTC4
0.5tCLCL - 8 +
0.5tCLCL - 8 +
ns
tSTC4
tSTC4
2.5tCLCL - 20
2.5tCLCL - 20
ns
ALE Low to PSEN Low
tLLPL
1.5tCLCL - 6
0.5tCLCL - 6
ns
PSEN Pulse Width for
Program Fetch
tPLPH
tCLCL - 5
tCLCL - 5
2tCLCL - 5
tCLCL - 5
2tCLCL - 5
ns
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