ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 50

• Manufacturer Part Number: ATmega32U4
• Manufacturer: Atmel Corporation

Specifications of ATmega32U4

• Flash (kbytes): 32 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 14
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 26
• Ext Interrupts: 13
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 3.3
• Eeprom (bytes): 1024
• 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: 12
• Input Capture Channels: 2
• Pwm Channels: 8
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

8.0.3
7766F–AVR–11/10
Power-on Reset
Figure 8-1.
Table 8-1.
Notes:
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level
is defined in
POR circuit can be used to trigger the start-up Reset, as 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
Symbol
V
V
V
V
t
CCRR
RST
POR
POT
RST
BODLEVEL [2..0]
1. The Power-on Reset will not work unless the supply voltage has been below V
Parameter
Power-on Reset Threshold Voltage (rising)
Power-on Reset Threshold Voltage (falling)
V
Reset signal
VCC Rise Rate to ensure internal Power_on
Reset signal
Minimum pulse width on RESET Pin
RESET Pin Threshold Voltage
CC
Table
Reset Logic
Reset Characteristics
Start Voltage to ensure internal Power-on
8-1. The POR is activated whenever V
Pull-up Resistor
JTAG Reset
Register
FILTER
SPIKE
CKSEL[3:0]
Power-on Reset
Reset Circuit
SUT[1:0]
USB Reset
Watchdog
Brown-out
Detection
Oscillator
Generator
Circuit
Clock
CK
Register (MCUSR)
(1)
MCU Status
DATA BUS
Delay Counters
Condition
5V, 25°C
CC
is below the detection level. The
ATmega16/32U4
Min
-0.1
Vcc
0.3
0.2
TIMEOUT
Typ
400
1.4
1.3
POT
+0.1
Max
0.85
Vcc
2.3
2.3
(falling)
Units
V/ms
ns
V
V
V
V
50