ATMEGA644PV ATMEL [ATMEL Corporation], ATMEGA644PV Datasheet - Page 52

• Manufacturer Part Number: ATMEGA644PV
• Description: 8-bit Microcontroller with 16/32/64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

9.0.4
52
ATmega164P/324P/644P
External Reset
Figure 9-2.
Figure 9-3.
An External Reset is generated by a low level on the RESET pin. Reset pulses longer than the
minimum pulse width (see
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
delay counter starts the MCU after the Time-out period – t
Figure 9-4.
INTERNAL
INTERNAL
TIME-OUT
TIME-OUT
RESET
RESET
RESET
RESET
V
V
CC
CC
CC
MCU Start-up, RESET Tied to V
MCU Start-up, RESET Extended Externally
External Reset During Operation
V
V
”System and Reset Characteristics” on page
V
POT
POT
RST
t
TOUT
CC
V
RST
t
TOUT
TOUT
– has expired.
RST
– on its positive edge, the
329) will generate a
8011D–AVR–02/07