atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 196

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

18. Serial Peripheral Interface – SPI
196
ATmega32U4
The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the
ATmega32U4 and peripheral devices or between several AVR devices. The 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 233.
The Power Reduction SPI bit, PRSPI, in
page 50 must be written to zero to enable SPI module.
Figure 18-1. 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
communication cycle when pulling low the Slave Select SS pin of the desired Slave. Master and
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
DIVIDER
“Pinout ATmega32U4” on page
(1)
“Power Reduction Register 0 - PRR0” on page 43
3, and
Table 10-3 on page 70
Figure
for SPI pin placement.
18-2. The sys-
7766A–AVR–03/08
on