
49
4431E–8051–04/06
AT/TS8xC54/8X2
Table 19-7.
AC Parameters for a Variable Clock: derating formula
19.5.3
External Program Memory Read Cycle
Figure 19-6. External Program Memory Read Cycle
Symbol
Type
Standard
Clock
X2 Clock
-M
-V
-L
Units
TLHLL
Min
2 T - x
T - x
10
8
15
ns
TAVLL
Min
T - x
0.5 T - x
15
13
20
ns
TLLAX
Min
T - x
0.5 T - x
15
13
20
ns
TLLIV
Max
4 T - x
2 T - x
30
22
35
ns
T
LLPL
Min
T - x
0.5 T - x
10
8
15
ns
TPLPH
Min
3 T - x
1.5 T - x
20
15
25
ns
TPLIV
Max
3 T - x
1.5 T - x
40
25
45
ns
TPXIX
Min
xx0
0
ns
TPXIZ
Max
T - x
0.5 T - x
7
5
15
ns
T
AVIV
Max
5 T - x
2.5 T - x
40
30
45
ns
TPLAZ
Max
x
10
ns
TPLIV
TPLAZ
ALE
PSEN
PORT 0
PORT 2
A0-A7
INSTR IN
ADDRESS
OR SFR-P2
ADDRESS A8-A15
12 TCLCL
TAVIV
T
LHLL
T
AVLL
T
LLIV
T
LLPL
TPLPH
TPXAV
T
PXIX
T
PXIZ
T
LLAX