title: direct Single Register Addressing AVR
body: <p>I was looking at Direct Single Register Addressing in Atmel AVR instruction set. In Page# 3 of instruction Set manual, it is written that Direct Single Register Addressing instruction contains Rd in bits 0 to 4 and opcode in rest of the 12 bits.  In such case where is the immediate value of 8 bits located? The figure 1 in the manual does not indicate the immediate value.
  Ex: LDI R18,0xff : In this instruction, if 5 bits are register address and 11 bits are Opcode, there is no immediate data!</p>
  
  <p>Or is Opcode is of 4 bits and rest are all for data?</p>
  
  <p><img src="https://i.stack.imgur.com/m42jL.jpg" alt="enter image description here"></p>