In 8051 RAM size is 128 bytes which is divided in to 3 areas like register bank ,Bit addressable are and scratch pad area. what is the location for SFR ? many literature stating that 8051 has 256 byte memory in it 128 byte for general purpose and rest 128 for special purpose which one is true ? i am confused about (1)what is the RAM size of 8051 weather 128 bytes or 256 bytes? (2) if the RAM size is 128 bytes what are location for the SFR ?