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External reset, Attiny15l – Rainbow Electronics ATtiny15L User Manual

Page 16

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16

ATtiny15L

1187E–AVR–06/02

Figure 13. “MCU Start-up, RESET Tied to V

CC

Figure 14. MCU Start-up, RESET Extended Externally

External Reset

An External Reset is generated by a low-level on the RESET pin. Reset pulses longer
than 500 ns will generate a reset, even if the clock is not running. Shorter pulses are not
guaranteed to generate a reset. When the applied signal reaches the Reset Threshold
Voltage (V

RST

) on its positive edge, the delay timer starts the MCU after the Time-out

period t

TOUT

has expired.

Figure 15. External Reset during Operation

VCC

RESET

TIME-OUT

INTERNAL

RESET

t

TOUT

V

POT

V

RST

VCC

RESET

TIME-OUT

INTERNAL

RESET

t

TOUT

V

POT

V

RST