18. SPI – Serial Peripheral Interface
18.1 Features
• 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
18.2 Overview
The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the
ATmega48/88/168 and peripheral devices or between several AVR devices.
The USART can also be used in Master SPI mode, see “USART in SPI Mode” on page 200. The
PRSPI bit in “Minimizing Power Consumption” on page 42 must be written to zero to enable SPI
module.
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ATmega48/88/168
2545M–AVR–09/07