AT89C51RE2-SLSUM Atmel, AT89C51RE2-SLSUM Datasheet - Page 125
![MCU 8BIT FLASH 2.7-5.5V 44-PLCC](/photos/6/70/67043/453-44-plcc_sml.jpg)
AT89C51RE2-SLSUM
Manufacturer Part Number
AT89C51RE2-SLSUM
Description
MCU 8BIT FLASH 2.7-5.5V 44-PLCC
Manufacturer
Atmel
Series
89Cr
Datasheet
1.AT89C51RE2-SLSUM.pdf
(187 pages)
Specifications of AT89C51RE2-SLSUM
Core Processor
8051
Core Size
8-Bit
Speed
60MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
POR, PWM, WDT
Number Of I /o
34
Program Memory Size
128KB (128K x 8)
Program Memory Type
FLASH
Ram Size
8K x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 5.5 V
Oscillator Type
External
Operating Temperature
-40°C ~ 85°C
Package / Case
44-PLCC
Package
44PLCC
Device Core
8051
Family Name
89C
Maximum Speed
40 MHz
Operating Supply Voltage
3.3|5 V
Data Bus Width
8 Bit
Number Of Programmable I/os
34
Interface Type
SPI/TWI/UART
Number Of Timers
3
Processor Series
AT89x
Core
8051
Data Ram Size
8 KB
Maximum Clock Frequency
40 MHz
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
PK51, CA51, A51, ULINK2
Development Tools By Supplier
AT89OCD-01
Minimum Operating Temperature
- 40 C
Cpu Family
89C
Device Core Size
8b
Frequency (max)
40MHz
Total Internal Ram Size
8KB
# I/os (max)
34
Number Of Timers - General Purpose
3
Operating Supply Voltage (typ)
3.3/5V
Operating Supply Voltage (max)
5.5V
Operating Supply Voltage (min)
2.7V
Instruction Set Architecture
CISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Surface Mount
Pin Count
44
Package Type
PLCC
For Use With
AT89OCD-01 - USB EMULATOR FOR AT8XC51 MCUAT89STK-11 - KIT STARTER FOR AT89C51RX2
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AT89C51RE2-SLSUM
Manufacturer:
HONEYWELL
Quantity:
101
WDT During Power
Down and Idle
7663E–8051–10/08
Table 93. WDTPRG Register
WDTPRG - Watchdog Timer Out Register (0A7h)
Reset value = XXXX X000
In Power Down mode the oscillator stops, which means the WDT also stops. While in Power
Down mode the user does not need to service the WDT. There are 2 methods of exiting Power
Down mode: by a hardware reset or via a level activated external interrupt which is enabled prior
to entering Power Down mode. When Power Down is exited with hardware reset, servicing the
WDT should occur as it normally should whenever the AT89C51RE2 is reset. Exiting Power
Down with an interrupt is significantly different. The interrupt is held low long enough for the
oscillator to stabilize. When the interrupt is brought high, the interrupt is serviced. To prevent the
WDT from resetting the device while the interrupt pin is held low, the WDT is not started until the
interrupt is pulled high. It is suggested that the WDT be reset during the interrupt service routine.
To ensure that the WDT does not overflow within a few states of exiting of powerdown, it is bet-
ter to reset the WDT just before entering powerdown.
In the Idle mode, the oscillator continues to run. To prevent the WDT from resetting the
AT89C51RE2 while in Idle mode, the user should always set up a timer that will periodically exit
Idle, service the WDT, and re-enter Idle mode.
Number
Bit
7
-
7
6
5
4
3
2
1
0
Mnemonic
Bit
S2
S1
S0
6
-
-
-
-
-
-
Description
Reserved
WDT Time-out select bit 2
WDT Time-out select bit 1
WDT Time-out select bit 0
S2
0
0
0
0
1
1
1
1
5
-
The value read from this bit is undetermined. Do not try to set this bit.
S1
0
0
1
1
0
0
1
1
S0
0
1
0
1
0
1
0
1
4
-
Selected Time-out
(2
(2
(2
(2
(2
(2
(2
(2
14
15
16
17
18
19
20
21
- 1) machine cycles, 16. 3 ms @ F
- 1) machine cycles, 32.7 ms @ F
- 1) machine cycles, 65. 5 ms @ F
- 1) machine cycles, 131 ms @ F
- 1) machine cycles, 262 ms @ F
- 1) machine cycles, 542 ms @ F
- 1) machine cycles, 1.05 s @ F
- 1) machine cycles, 2.09 s @ F
3
-
S2
2
AT89C51RE2
OSCA
OSCA
S1
OSCA
OSCA
OSCA
1
OSCA
OSCA
OSCA
=12 MHz
=12 MHz
=12 MHz
=12 MHz
=12 MHz
=12 MHz
=12 MHz
=12 MHz
S0
0
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