Is a 64 bit register. (double word)

• 0 to 63 bites in Register or Memory
• which is 8 bytes: B0, B1, … B7
  • Byte 0 holds least significant

How to store in Memory? Little-Endian Increment the address by 8 if we want to access Byte 8 for RV64I. To get to the next double word instructions.

Review RV64I number of addressable double words = 2^61 double words is 8B needs 3 bits of the address to identify which byte it’s addressing in the double words. We are left 2 to the 61????