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ELECTRICAL CHARACTERISTICS
221
6.4 External Program Memory Access AC Characteristics
V
CC
=2.2 to 6.0V, V
SS
=0V, Ta=–40°C to +85°C
PORT 0, ALE, and PSEN connected with 100pF load, other connected with 80pF load
Parameter Symble Unit
Min. Max.
1 to 24 MHz
Variable clock from
41.7 1000 ns
t
CLCL
XTAL1, XTAL 2 Oscillation Cycle
2t
CLCL
-40 — ns
t
LHLL
ALE Signal Width
1t
CLCL
-15 — ns
t
AVLL
Address Setup Time
(to ALE Falling Edge)
1t
CLCL
-35 — ns
t
LLAX
Address Hold Time
(from ALE Falling Edge)
—4t
CLCL
-100 ns
t
LLPL
Instruction Data Read Time
(from ALE Falling Edge)
1t
CLCL
-30 — ns
t
LLPL
From ALE Falling Edge to PSEN
Falling Edge
3t
CLCL
-35 — ns
t
PLPH
PSEN Signal Width
—3t
CLCL
-45 ns
t
PLIV
Instruction Data Read Time
(from PSEN Falling Edge)
0—ns
t
PXIX
Instruction Data Hold Time
(from PSEN Rising Edge)
—1t
CLCL
-20 ns
t
PXIZ
Bus Floating Time after Instruction
Data Read (from PSEN Rising Edge)
—5t
CLCL
-105 ns
t
AVIV
Instruction Data Read Time
(from Address Output)
0—ns
t
AZPL
Bus Floating Time(PSEN Rising
Edge from Address float)
1t
CLCL
-20 — ns
t
PXAV
Address Output Time from PSEN
Rising Edge
*1
*1 The variable check is from 0 to 24 MHz when the external check is used.