ATMEGA32U4-AU Atmel, ATMEGA32U4-AU Datasheet - Page 33

• Manufacturer Part Number: ATMEGA32U4-AU
• Description: MCU AVR 32K FLASH 16MHZ 44-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32U4-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 26
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2.5K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: ATMEGA32x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2.5 KB
• Interface Type: SPI/TWI/USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 26
• Number Of Timers: 5
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12-ch x 10-bit
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 16MHz
• Total Internal Ram Size: 2.5KB
• # I/os (max): 26
• Number Of Timers - General Purpose: 5
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 44
• Package Type: TQFP
• Controller Family/series: AVR MEGA
• No. Of I/o's: 26
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2.5KB
• Cpu Speed: 16MHz
• Rohs Compliant: Yes
• For Use With: ATSTK524 - KIT STARTER ATMEGA32M1/MEGA32C1ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATMEGA32U4-16AU; ATMEGA32U4-16AU

6.5.2
6.6
7766F–AVR–11/10
External Clock
Oscillator Control Register – RCCTRL
The temperature sensitivity is quite linear but as said previously depends on the process. To
determine its slope, the frequency must be measured at two temperatures. The temperature
sensor of the ATmega16U4/ATmega32U4 allows such an operation, that is detailed on
24.6.1 ”Sensor Calibration” on page
in function of the temperature measured.
Note that this oscillator is used to time EEPROM and Flash write accesses, and these write
times will be affected accordingly. If the EEPROM or Flash are written, do not calibrate to more
than 8.8 MHz. Otherwise, the EEPROM or Flash write may fail.
Bits 7..1 – Reserved
Do not set these bits. Bits should be read as ‘0’.
Bit 0– RCFREQ: RC Oscillator Frequency Select
When this bit is cleared (default value), the RC Oscillator output frequency is set to 8 MHz.
When the bit is set, the RC output frequency is 1 MHz. Note that the OSCCAL value has the
same effect on both 8 MHz and 1 MHz output modes (~0.4% / step).
The device can utilize a external clock source as shown in
external clock, the CKSEL Fuses must be programmed as shown in
Figure 6-3.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Bit
Read/Write
Initial Value
6-9.
7
-
R
0
External Clock Drive Configuration
6
-
R
0
EXTERNAL
SIGNAL
CLOCK
5
-
R
0
NC
300. It is then possible to calibrate the oscillator frequency
4
-
R
0
3
-
R
0
XTAL2
XTAL1
GND
2
-
R
0
Figure
1
-
R
0
ATmega16/32U4
6-3. To run the device on an
Table
0
RCFREQ
R/W
0
6-1.
RCCTRL
Section
33