#include <8051io.h>
#define OFFSET 0x300
struct _header
{
unsigned char byte;
unsigned int word;
};
unsigned char GetExpandData( unsigned int address)
{
asm
{
MOV A,#-3
ADD A,SP Adjust for stack offset
XCH A,R0
MOV DPL,[R0]
INC R0
MOV DPH,[R0]
MOVX A,@DPTR
RET
}
}
void SetExpandData( unsigned int address,unsigned char data )
{
asm
{
MOV A,#-5
ADD A,SP Adjust for stack offset
XCH A,R0 And restore order
MOV DPL,[R0]
INC R0
MOV DPH,[R0]
INC R0
MOV A,[R0]
MOVX @DPTR,A
RET
}
}
register unsigned int G_offSet;
void memset (register unsigned char* dest,
register unsigned char* source,
unsigned int len)
{
unsigned int address;
unsigned char ndx;
address = dest + G_offSet;
for (ndx =0 ; ndx < len; ndx++)
SetExpandData(address++,*source++);
}
void memget (register unsigned char* dest,
register unsigned char* source,
unsigned int len)
{
unsigned int address;
unsigned char ndx;
address = source + G_offSet;
for (ndx =0 ; ndx < len; ndx++)
*dest++ = GetExpandData(address++);
}
void main()
{
unsigned int address;
unsigned char dataByte;
unsigned int dataWord;
struct _header *pt;
serinit(9600);
asm
{
MOV 8EH,#0CH ; Enable Expanded memory
; Clear all locations of expanded memory
MOV DPTR,#0
NEXT:
CLR A
MOVX @DPTR,A
INC DPTR
MOV A,DPH
JNB ACC.2,NEXT
}
pt =0;
G_offSet = OFFSET; // set offset inside of Expanded memory
//
dataByte = 0xA5;
dataWord = 0x1234;
memset(&pt->byte,&dataByte,sizeof(pt->byte)); // write byte
memset(&pt->word,&dataWord,sizeof(pt->word)); // write word
//
dataByte = 0x00;
dataWord = 0x0000;
memget(&dataByte,&pt->byte,sizeof(pt->byte)); // read byte
memget(&dataWord,&pt->word,sizeof(pt->word)); // read word
//
printf("\\ndataByte = %02x ",dataByte);
printf("\\ndataWord = %04x ",dataWord);
for(address= 0; address < 0x400; address++)
{
if(!(address % 16))
{
printf("\\n%04x ",address);
}
printf("%02x ",GetExpandData(address));
}
for(;
;
}
