at89c55-16qa ATMEL Corporation, at89c55-16qa Datasheet - Page 22

• Manufacturer Part Number: at89c55-16qa
• Description: 8-bit Microcontroller With Bytes Flash
• Manufacturer: ATMEL Corporation

Serial Port Timing: Shift Register Mode Test Conditions
The values in this table are valid for V
Shift Register Mode Timing Waveforms
AC Testing Input/Output Waveforms
Note:
4-190
Symbol
t
t
t
t
t
XLXL
QVXH
XHQX
XHDX
XHDV
1.
AC Inputs during testing are driven at V
logic 1 and 0.45V for a logic 0. Timing measurements
are made at V
logic 0.
Parameter
Serial Port Clock Cycle Time
Output Data Setup to Clock Rising Edge
Output Data Hold After Clock Rising Edge
Input Data Hold After Clock Rising Edge
Clock Rising Edge to Input Data Valid
IH
min. for a logic 1 and V
AT89C55
CC
= 5.0V
CC
IL
max. for a
20% and Load Capacitance = 80 pF.
- 0.5V for a
(1)
Float Waveforms
Note:
10t
2t
CLCL
12t
CLCL
Min
1.
CLCL
0
- 117
- 133
For timing purposes, a port pin is no longer
floating when a 100 mV change from load volt-
age occurs. A port pin begins to float when a
100 mV change from the loaded V
occurs.
(1)
10t
CLCL
Max
- 133
OH
/V
Units
OL
ns
ns
ns
ns
ns
level