ATMEGA168PA-PU Atmel, ATMEGA168PA-PU Datasheet - Page 48

• Manufacturer Part Number: ATMEGA168PA-PU
• Description: MCU, 8BIT, AVR, 16K FLASH, 28PDIP
• Manufacturer: Atmel

Specifications of ATMEGA168PA-PU

• Controller Family/series: Atmega
• No. Of I/o's: 23
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 1KB
• Cpu Speed: 20MHz
• No.: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 16KB
• Oscillator Type: External, Internal
• Rohs Compliant: Yes

10.3
8271C–AVR–08/10
Power-on Reset
Figure 10-1. Reset Logic
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level
is defined in
V
well as to detect a failure in supply voltage.
A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the
Power-on Reset threshold voltage invokes the delay counter, which determines how long the
device is kept in RESET after V
when V
Figure 10-2. MCU Start-up, RESET Tied to V
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
CC
is below the detection level. The POR circuit can be used to trigger the start-up Reset, as
INTERNAL
TIME-OUT
BODLEVEL [2..0]
RSTDISBL
CC
RESET
RESET
V
decreases below the detection level.
CC
”System and Reset Characteristics” on page
Pull-up Resistor
FILTER
SPIKE
V
V
POT
RST
CC
t
TOUT
CKSEL[3:0]
rise. The RESET signal is activated again, without any delay,
Power-on Reset
Reset Circuit
SUT[1:0]
Brown-out
Watchdog
Oscillator
Generator
Circuit
Clock
CK
CC
Register (MCUSR)
MCU Status
DATA BUS
Delay Counters
323. The POR is activated whenever
TIMEOUT
48