AT89C51RC Atmel Corporation, AT89C51RC Datasheet - Page 31

• Manufacturer Part Number: AT89C51RC
• Manufacturer: Atmel Corporation

Specifications of AT89C51RC

• Flash (kbytes): 32 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Uart: 1
• Sram (kbytes): 0.5
• Operating Voltage (vcc): 4.0 to 6.0
• Timers: 3
• Watchdog: Yes

35. Serial Port Timing: Shift Register Mode Test Conditions
The values in this table are valid for V
36. Shift Register Mode Timing Waveforms
37. AC Testing Input/Output Waveforms
38. Float Waveforms
1920D–MICRO–6/08
Symbol
t
t
t
t
t
XLXL
QVXH
XHQX
XHDX
XHDV
INSTRUCTION
WRITE TO SBUF
OUTPUT DATA
INPUT DATA
CLEAR RI
CLOCK
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
ALE
Note:
Note:
(1)
0
t
V
QVXH
V
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
LOAD
CC
CC
for a logic 1 and 0.45V for a logic 0. Timing measurements are made at V
and V
occurs. A port pin begins to float when a 100 mV change from the loaded V
occurs.
- 0.5V
0.45V
t
= 4.0V to 5.5V and Load Capacitance = 80 pF.
1
XHDV
V
V
IL
0
LOAD
LOAD
VALID
max. for a logic 0.
+ 0.1V
- 0.1V
2
t
XLXL
t
1
XHQX
VALID
Timing Reference
0.2 V
0.2 V
TEST POINTS
(1)
3
Min
700
1.0
50
Points
t
0
12 MHz Osc
XHDX
2
VALID
CC
CC
+ 0.9V
- 0.1V
4
Max
700
3
VALID
CC
- 0.5V
V
V
OL
OL
5
- 0.1V
+ 0.1V
10t
4
2t
VALID
12t
CLCL
CLCL
Min
Variable Oscillator
0
CLCL
- 133
- 80
6
5
VALID
10t
7
AT89C51RC
CLCL
6
VALID
Max
IH
- 133
SET TI
OH
SET RI
min. for a logic 1
8
/V
OL
7
VALID
level
Units
µs
ns
ns
ns
ns
31