AT89C51ID2 Atmel Corporation, AT89C51ID2 Datasheet - Page 34

• Manufacturer Part Number: AT89C51ID2
• Manufacturer: Atmel Corporation

Specifications of AT89C51ID2

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 2
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

The Power fail detect monitor the supply generated by the voltage regulator and gener-
ate a reset if this supply falls below a safety threshold as illustrated in the Figure 11
below.
Figure 11. Power Fail Detect
Vcc
t
Reset
Vcc
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 lev-
els 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.
AT89C51ID2
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