Rainbow Electronics AT90LS4433 - Manual (Page 24)

24
AT90S/LS4433
1042G–AVR–09/02
Figure 25. MCU Start-up, RESET Tied to V
CC
Figure 26. MCU Start-up, RESET Controlled Externally
External Reset An External Reset is generated by a low level on the RESET pin. Reset pulses longer
than 50 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 27. 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