Datasheet

37
AT89C5132
4173C–USB–07/04
Figure 17. AC Testing Input/Output Waveforms
Notes: 1. During AC testing, all inputs are driven at V
DD
-0.5V for a logic 1 and 0.45V for a logic 0.
2. Timing measurements are made on all outputs at V
IH
min for a logic 1 and V
IL
max for a logic 0.
Figure 18. Float Waveforms
Note: For timing purposes, a 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 loading V
OH
/V
OL
level occurs with I
OL
/I
OH
= ±20 mA.
0.45 V
V
DD
- 0.5
0.7
V
DD
0.3 V
DD
V
IH
min
V
IL
max
INPUTS OUTPUTS
V
LOAD
V
OH
- 0.1V
V
OL
+ 0.1V
V
LOAD
+ 0.1V
V
LOAD
- 0.1V
Timing Reference Points