The 8051 Microcontroller and Embedded

Department of Computer Scien

ce and Information Engineering

National Cheng Kung University

HANEL

8051 DATA MEMORY SPACEInterfacing to Large External Memory(cont’)

....For example, to access the 20000H – 2FFFFH address space we need the following :

CLR P1.2 ;enable external RAMMOV DPTR,#0 ;start

of 64K memory block

CLR P1.0 ;A16 = 0SETB P1.1 ;A17

= 1 for 20000H block

MOV A,SBUF ;get data from serial portMOVX @DPTR,AINC DPTR ;next location...