AT89C55WD-24AI Atmel, AT89C55WD-24AI Datasheet - Page 17
![IC MICRO CTRL 24MHZ 44TQFP](/photos/6/70/67042/313-44-tqfp_sml.jpg)
AT89C55WD-24AI
Manufacturer Part Number
AT89C55WD-24AI
Description
IC MICRO CTRL 24MHZ 44TQFP
Manufacturer
Atmel
Series
89Cr
Datasheet
1.AT89C55WD-24AU.pdf
(35 pages)
Specifications of AT89C55WD-24AI
Core Processor
8051
Core Size
8-Bit
Speed
24MHz
Connectivity
UART/USART
Peripherals
WDT
Number Of I /o
32
Program Memory Size
20KB (20K x 8)
Program Memory Type
FLASH
Ram Size
256 x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-TQFP, 44-VQFP
Data Bus Width
8 bit
Data Ram Size
256 B
Maximum Clock Frequency
33 MHz
Number Of Programmable I/os
32
Number Of Timers
3 x 16 bit
Operating Supply Voltage
4 V to 5.5 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Eeprom Size
-
Data Converters
-
Lead Free Status / Rohs Status
No RoHS Version Available
Other names
AT89C55WD24AI
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
1921D–MICRO–6/08
The Timer 0 and Timer 1 flags, TF0 and TF1, are set at S5P2 of the cycle in which the timers
overflow. The values are then polled by the circuitry in the next cycle. However, the Timer 2 flag,
TF2, is set at S2P2 and is polled in the same cycle in which the timer overflows.
Table 15-1.
Figure 15-1. Interrupt Sources
Symbol
EA
–
ET2
ES
ET1
EX1
ET0
EX0
User software should never write 1s to reserved bits, because they may be used in future AT89
products.
(MSB)
Enable Bit = 1 enables the interrupt.
Enable Bit = 0 disables the interrupt.
EA
Interrupt Enable (IE) Register
Position
IE.7
IE.6
IE.5
IE.4
IE.3
IE.2
IE.1
IE.0
–
EXF2
INT0
INT1
TF0
TF1
TF2
RI
TI
ET2
Function
Disables all interrupts. If EA = 0, no interrupt is acknowledged. If EA
= 1, each interrupt source is individually enabled or disabled by
setting or clearing its enable bit.
Reserved.
Timer 2 interrupt enable bit.
Serial Port interrupt enable bit.
Timer 1 interrupt enable bit.
External interrupt 1 enable bit.
Timer 0 interrupt enable bit.
External interrupt 0 enable bit.
0
1
0
1
ES
ET1
(LSB)
EX1
IE0
IE1
ET0
AT89C55WD
EX0
17