ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 177

• 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

17. Serial Peripheral Interface – SPI
7766F–AVR–11/10
The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the
ATmega16U4/ATmega32U4 and peripheral devices or between several AVR devices. The
ATmega16U4/ATmega32U4 SPI includes the following features:
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USART can also be used in Master SPI mode, see “USART in SPI Mode” on page 214.
The Power Reduction SPI bit, PRSPI, in
page 50 must be written to zero to enable SPI module.
Figure 17-1. SPI Block Diagram
Note:
The interconnection between Master and Slave CPUs with SPI is shown in
tem consists of two shift Registers, and a Master clock generator. The SPI Master initiates the
Full-duplex, Three-wire Synchronous Data Transfer
Master or Slave Operation
LSB First or MSB First Data Transfer
Seven Programmable Bit Rates
End of Transmission Interrupt Flag
Write Collision Flag Protection
Wake-up from Idle Mode
Double Speed (CK/2) Master SPI Mode
1. Refer to
/2/4/8/16/32/64/128
pin placement.
DIVIDER
“Pinout ATmega16U4/ATmega32U4” on page
(1)
“Power Reduction Register 0 - PRR0” on page 46
3, and
ATmega16/32U4
Table 10-3 on page 72
Figure
17-2. The sys-
for SPI
177
on