24.5.3 SPI Data Register 0

When addressing I/O Registers as data space using LD and ST instructions, the provided offset must be used. When using the I/O specific commands IN and OUT, the offset is reduced by 0x20, resulting in an I/O address offset within 0x00 - 0x3F.

Name: SPDR
Offset: 0x4E
Reset: 0xXX
Property: When addressing as I/O Register: address offset is 0x2E

Bit 76543210 
 SPID[7:0] 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset xxxxxxxx 

Bits 7:0 – SPID[7:0] 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 register causes the Shift Register Receive buffer to be read.