AT89C52-20QC Atmel, AT89C52-20QC Datasheet - Page 21

• Manufacturer Part Number: AT89C52-20QC
• Description: Microcontrollers (MCU) Microcontroller
• Manufacturer: Atmel

Specifications of AT89C52-20QC

• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 8 KB
• Data Ram Size: 256 B
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: PQFP-44
• Minimum Operating Temperature: 0 C
• Lead Free Status / Rohs Status: No

.
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:
Symbol
t
t
t
t
t
XLXL
QVXH
XHQX
XHDX
XHDV
V
CC
INSTRUCTION
WRITE TO SBUF
- 0.5V
0.45V
OUTPUT DATA
INPUT DATA
1. AC Inputs during testing are driven at V
CLEAR RI
for a logic 1 and 0.45V for a logic 0. Timing measure-
ments are made at V
for a logic 0.
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
0.2 V
0.2 V
TEST POINTS
IH
0
CC
CC
min. for a logic 1 and V
t
QVXH
+ 0.9V
- 0.1V
CC
t
= 5.0V 20% and Load Capacitance = 80 pF.
1
XHDV
0
VALID
CC
- 0.5V
2
t
XLXL
IL
t
1
XHQX
VALID
(1)
max.
3
t
Min
700
XHDX
1.0
2
50
0
VALID
Float Waveforms
Note:
12 MHz Osc
V
LOAD
4
1. For timing purposes, a port pin is no longer floating
3
Max
700
VALID
when a 100 mV change from load voltage occurs. A
port pin begins to float when a 100 mV change from
the loaded V
V
V
LOAD
LOAD
5
+ 0.1V
- 0.1V
4
VALID
10t
2t
12t
CLCL
CLCL
Min
OH
Variable Oscillator
0
CLCL
Timing Reference
6
/V
-117
(1)
-133
OL
5
VALID
Points
level occurs.
7
10t
6
VALID
CLCL
Max
-133
SET TI
V
SET RI
V
OL
OL
8
- 0.1V
+ 0.1V
7
VALID
Units
µs
ns
ns
ns
ns
21