AT89C51RE2-RLTUM Atmel, AT89C51RE2-RLTUM Datasheet - Page 162

• Manufacturer Part Number: AT89C51RE2-RLTUM
• Description: MCU 8051 128K FLASH 44-VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51RE2-RLTUM

• 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-TQFP, 44-VQFP
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 8 KB
• Interface Type: UART, SPI
• Maximum Clock Frequency: 60 MHz
• Number Of Programmable I/os: 34
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• 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
• Height: 1.45 mm
• Length: 10.1 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Width: 10.1 mm
• For Use With: AT89STK-11 - KIT STARTER FOR AT89C51RX2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

Figure 67. Power Fail Detect
162
Vcc
AT89C51RE2
Vcc
Reset
The Power fail detect monitor the supply generated by the voltage regulator and generate a
reset if this supply falls below a safety threshold as illustrated in the Figure 67 below.
When the power is applied, the Power Monitor immediately asserts a reset. Once the internal
supply after the voltage regulator reach a safety level, the power monitor then looks at the XTAL
clock input. The internal reset will remain asserted until the Xtal1 levels are above and below
VIH and VIL. Further more. An internal counter will count 1024 clock periods before the reset is
de-asserted.
If the internal power supply falls below a safety level, a reset is immediately asserted.
t
7663E–8051–10/08