Manual

23
AT90S/LS8535
1041H–11/01
Figure 24. MCU Start-up, RESET Tied to V
CC
.
Figure 25. 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 26. 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