ATmega48 Automotive Atmel Corporation, ATmega48 Automotive Datasheet - Page 43

• Manufacturer Part Number: ATmega48 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega48 Automotive

• Flash (kbytes): 4 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 256
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 125
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

9.5
9.6
7701E–AVR–02/11
Brown-out Detection
Watchdog Reset
Figure 9-4.
ATtiny24/44/84 has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
during operation by comparing it to a fixed trigger level. The trigger level for the BOD can be
selected by the BODLEVEL Fuses. The trigger level has a hysteresis to ensure spike free
Brown-out Detection. The hysteresis on the detection level should be interpreted as
V
When the BOD is enabled, and V
ure 9-5 on page
above the trigger level (V
after the Time-out period t
The BOD circuit will only detect a drop in V
ger than t
Figure 9-5.
When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration.
On the falling edge of this pulse, the delay timer starts counting the Time-out period t
“Watchdog Timer” on page 44
BOT+
= V
BOD
BOT
CC
given in
+ V
INTERNAL
TIME-OUT
External Reset During Operation
Brown-out Reset During Operation
RESET
RESET
HYST
43), the Brown-out Reset is immediately activated. When V
V
CC
/2 and V
“System and Reset Characterizations” on page
TOUT
BOT+
Atmel ATtiny24/44/84 [Preliminary]
BOT-
for details on operation of the Watchdog Timer.
has expired.
in
CC
Figure 9-5 on page
= V
decreases to a value below the trigger level (V
V
BOT
BOT-
- V
CC
HYST
if the voltage stays below the trigger level for lon-
/2.
43), the delay counter starts the MCU
V
t
TOUT
BOT+
181.
CC
BOT-
increases
TOUT
CC
in
. See
level
Fig-
43