Rainbow Electronics AT89C5131 - Manual (Page 163)

163
AT89C5131
4136A–USB–03/03
Shift Register Timing Waveform
External Clock Drive
Characteristics (XTAL1) Table 113. AC Parameters
External Clock Drive
Waveforms
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”.
Float Waveforms
For timing purposes as port pin is no longer floating when a 100 mV change from load
voltage occurs and begins to float when a 100 mV change from the loaded V
OH
/V
OL
level
occurs. I
OL
/I
OH
≥ ±
20 mA.
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
-0.5V
0.45V
FLOAT
V
OH
- 0.1 V
V
OL
+ 0.1 V
V
LOAD
V
LOAD
+ 0.1 V
V
LOAD
- 0.1 V