Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

HANEL

EXTRA 128 BYTE ON-CHIP RAM IN 8052

‰The 8052 has another 128 bytes of on-chip RAM with addresses 80

– FFH

¾It is often called upper memory

ƒUse indirect addressing mode, which uses R0 and R1 registers as pointe

rs with values of 80H

or higher– MOV @R0, A

and

MOV @R1, A

¾The same address space assigned to the SFRs

ƒUse direct addressing mode

• MOV 90H, #55H

is the same as

MOV P1, #55H