
37
4428E–8051–02/08
AT/TS80C31X2
Table 14-13. AC Parameters for a Variable Clock: derating formula
14.5.5
Shift Register Timing Waveforms
Figure 14-9. Shift Register Timing Waveforms
Table 14-14. External Clock Drive Characteristics (XTAL1)
Symbol
Type
Standard
Clock
X2 Clock
-M
-V
-L
Units
TXLXL
Min
12 T
6 T
ns
TQVHX
Min
10 T - x
5 T - x
50
ns
TXHQX
Min
2 T - x
T - x
20
ns
TXHDX
Min
x
0
ns
TXHDV
Max
10 T - x
5 T- x
133
ns
VALID
INPUT DATA
VALID
0
1
2
3
4
5
6
8
7
ALE
CLOCK
OUTPUT DATA
WRITE to SBUF
CLEAR RI
TXLXL
TQVXH
T
XHQX
TXHDV
TXHDX
SET TI
SET RI
INSTRUCTION
0
1
2
3
4
5
6
7
VALID
Symbol
Parameter
Min
Max
Units
TCLCL
Oscillator Period
25
ns
TCHCX
High Time
5
ns
TCLCX
Low Time
5
ns
TCLCH
Rise Time
5
ns
TCHCL
Fall Time
5
ns
TCHCX/TCLCX
Cyclic ratio in X2 mode
40
60
%