ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 54

• Manufacturer Part Number: ATmega64
• Manufacturer: Atmel Corporation

Specifications of ATmega64

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• 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): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

External Reset
Brown-out Detection
2490Q–AVR–06/10
An External Reset is generated by a low level on the RESET pin. Reset pulses longer than the
minimum pulse width (see
Shorter pulses are not guaranteed to generate a reset. When the applied signal reaches the
Reset Threshold Voltage – V
Time-out period t
Figure 25. External Reset during Operation
ATmega64 has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
ing operation by comparing it to a fixed trigger level. The trigger level for the BOD can be
selected by the fuse BODLEVEL to be 2.7V (BODLEVEL unprogrammed), or 4.0V (BODLEVEL
programmed). The trigger level has a hysteresis to ensure spike free Brown-out Detection. The
hysteresis on the detection level should be interpreted as V
V
The BOD circuit can be enabled/disabled by the fuse BODEN. When the BOD is enabled
(BODEN programmed), and V
26), the Brown-out Reset is immediately activated. When V
(V
expired.
The BOD circuit will only detect a drop in V
ger than t
Figure 26. Borwn-out Reset During Operation
BOT
BOT+
- V
INTERNAL
TIME-OUT
in
HYST
BOD
RESET
RESET
Figure
CC
V
/2.
given in
CC
TOUT
26), the delay counter starts the MCU after the Time-out period t
has expired.
Table
19.
Table
RST
CC
on its positive edge, the delay counter starts the MCU after the
decreases to a value below the trigger level (V
19) will generate a reset, even if the clock is not running.
V
BOT-
CC
if the voltage stays below the trigger level for lon-
CC
BOT+
increases above the trigger level
V
t
= V
TOUT
BOT+
BOT
ATmega64(L)
+ V
HYST
/2 and V
BOT-
CC
level dur-
TOUT
in
Figure
BOT-
has
54
=