Question: what are sfr in 8051?
Answer: In the 8051, register A, B, DPTR, and PSW are a part of the group of registers commonly referred to as SFR (special function registers). ... A special function register can have an address between 80H to FFH. These addresses are above 80H, as the addresses from 00 to 7FH are the addresses of RAM memory inside the 8051.