Rainbow Electronics ATmega64M1 - Manual (Page 163)

163
8209A–AVR–08/09
ATmega16M1/32M1/64M1
19.5.4 SPDR – SPI Data Register
• Bits 7:0 - SPD7:0: SPI Data
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 regis-
ter causes the Shift Register Receive buffer to be read.
Bit 7 6 5 4 3 2 1 0
SPD7 SPD6 SPD5 SPD4 SPD3 SPD2 SPD1 SPD0 SPDR
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value X X X X X X X X Undefined