AT89C51ID2-SMSIM ATMEL [ATMEL Corporation], AT89C51ID2-SMSIM Datasheet - Page 35

• Manufacturer Part Number: AT89C51ID2-SMSIM
• Description: 8-bit Flash Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 12. Power Fail Detect
4289A–8051–09/03
Vcc
Vcc
Reset
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 12
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 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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