
148
AT89C51ID2
4289C–8051–11/05
Table 105. AC Parameters for a Fix Clock
Table 106. AC Parameters for a Variable Clock
Shift Register Timing
Waveforms
External Clock Drive
Waveforms
Symbol
-M
-L
Units
Min
Max
Min
Max
T
XLXL
300
ns
T
QVHX
200
ns
T
XHQX
30
ns
T
XHDX
00
ns
T
XHDV
117
ns
Symbol
Type
Standard
Clock
X2 Clock
X Parameter For
-M Range
X Parameter For
-L Range
Units
T
XLXL
Min
12 T
6 T
ns
T
QVHX
Min
10 T - x
5 T - x
50
ns
T
XHQX
Min
2 T - x
T - x
20
ns
T
XHDX
Min
x
0
ns
T
XHDV
Max
10 T - x
5 T- x
133
ns
INPUT DATA
VALID
0
1
23
45
6
8
7
ALE
CLOCK
OUTPUT DATA
WRITE to SBUF
CLEAR RI
T
XLXL
T
QVXH
T
XHQX
T
XHDV
T
XHDX
SET TI
SET RI
INSTRUCTION
01
2
3
4
5
67
VALID
V
CC-0.5V
0.45V
0.7V
CC
0.2V
CC-0.1
T
CHCL
T
CLCX
T
CLCL
T
CLCH
T
CHCX