Datasheet

170
4337K–USB–04/08
AT89C5130A/31A-M
27.4.8 Shift Register Timing Waveform
27.4.9 External Clock Drive Characteristics (XTAL1)
Table 27-11. AC Parameters
27.4.10 External Clock Drive Waveforms
27.4.11 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”.
27.4.12 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 87
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 21 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