at89s51-33sc ATMEL Corporation, at89s51-33sc Datasheet - Page 26

• Manufacturer Part Number: at89s51-33sc
• Description: At89s51, 8-bit Microcontroller With 4k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

30. Serial Port Timing: Shift Register Mode Test Conditions
The values in this table are valid for V
31. Shift Register Mode Timing Waveforms
32. AC Testing Input/Output Waveforms
Note:
33. Float Waveforms
Note:
26
Symbol
t
t
t
t
t
XLXL
QVXH
XHQX
XHDX
XHDV
1. AC Inputs during testing are driven at V
1. For timing purposes, a port pin is no longer floating when a 100 mV change from load voltage occurs. A port pin begins to
INSTRUCTION
min. for a logic 1 and V
float when a 100 mV change from the loaded V
WRITE TO SBUF
OUTPUT DATA
INPUT DATA
CLEAR RI
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
AT89S51
CLOCK
ALE
(1)
IL
max. for a logic 0.
0
t
V
QVXH
V
LOAD
CC
CC
= 4.0V to 5.5V and Load Capacitance = 80 pF.
- 0.5V
0.45V
t
1
XHDV
V
V
LOAD
0
LOAD
VALID
CC
- 0.5V for a logic 1 and 0.45V for a logic 0. Timing measurements are made at V
+ 0.1V
- 0.1V
2
t
XLXL
t
1
OH
XHQX
VALID
/V
Timing Reference
OL
0.2 V
0.2 V
(1)
TEST POINTS
3
level occurs.
Points
t
Min
700
2
XHDX
1.0
50
VALID
0
CC
CC
12 MHz Osc
+ 0.9V
- 0.1V
4
3
VALID
Max
700
V
V
OL
OL
5
- 0.1V
+ 0.1V
4
VALID
10 t
2 t
12 t
CLCL
CLCL
6
Min
Variable Oscillator
0
CLCL
5
VALID
-133
-80
7
6
VALID
10 t
SET TI
SET RI
CLCL
Max
8
7
-133
VALID
2487C–MICRO–03/05
Units
ns
µs
ns
ns
ns
IH