at89c55-12qi ATMEL Corporation, at89c55-12qi Datasheet - Page 22

• Manufacturer Part Number: at89c55-12qi
• 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
22
Note:
Symbol
t
t
t
t
t
XLXL
QVXH
XHQX
XHDX
XHDV
1. AC Inputs during testing are driven at V
for a logic 1 and 0.45V for a logic 0. Timing meas-
urements are made at V
V
IL
max. for a 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
AT89C55
IH
min. for a logic 1 and
CC
= 5.0V
CC
- 0.5V
20% and Load Capacitance = 80 pF.
(1)
Min
700
1.0
Float Waveforms
12 MHz Osc
50
Note:
0
1. For timing purposes, a port pin is no longer floating
Max
700
when a 100 mV change from load voltage occurs. A
port pin begins to float when a 100 mV change from
the loaded V
10t
2t
12t
CLCL
CLCL
OH
Min
Variable Oscillator
/V
CLCL
0
(1)
OL
- 133
- 33
level occurs.
10t
CLCL
Max
- 133
Units
ns
ns
ns
ns
ns