Rainbow Electronics T89C51AC2 - Manual (Page 103)

103
T89C51AC2
Rev. B – 19-Dec-01
18.4.8 Shift Register Timing
Waveforms
18.4.9 External Clock Drive
Characteristics (XTAL1) Table 68. AC Parameters
18.4.10 External Clock Drive
Waveforms
18.4.11 AC Testing
Input/Output Waveforms
AC inputs during testing are driven at V
CC
- 0.5 for a logic “1” and 0.45V for a logic “0”.
Timing measurement are made at V
IH
min for a logic “1” and V
IL
max for a logic “0”.
VALID VALID VALID VALID VALID VALID INPUT DATA VALID
0 1 2 3 4 5 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
0 1 2 3 4 5 6 7
VALID
Symbol Parameter Min Max Units
T
CLCL
Oscillator Period 25 ns
T
CHCX
High Time 5 ns
T
CLCX
Low Time 5 ns
T
CLCH
Rise Time 5 ns
T
CHCL
Fall Time 5 ns
T
CHCX
/T
CLCX
Cyclic ratio in X2 mode 40 60 %
V
CC
-0.5V
0.45V
0.7V
CC
0.2V
CC
-0.1
T
CHCL
T
CLCX
T
CLCL
T
CLCH
T
CHCX
INPUT/OUTPUT
0.2 V
CC
+ 0.9
0.2 V
CC
- 0.1
V
CC
-0.5 V
0.45 V