Datasheet

ATmega164A/PA/324A/PA/644A/PA/1284/P
 2018 Microchip Technology Inc. Data Sheet Complete DS40002070A-page 174
18.5.3 SPDR – SPI Data Register
The SPI Data Register is a read/write register used for data transfer between the Register File and the SPI Shift
Register. Writing to the register initiates data transmission. Reading the register causes the Shift Register
Receive buffer to be read.
Bit 76543210
0x2E (0x4E) MSB LSB SPDR
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial ValueXXXXXXXXUndefined