hi thomas;
80c31 has external eprom for code,isn't
it?u are latching address msb on p2.but their
is a problem.ur instructions are being executed from exteranl eprom/rom.so on next
instruction fetch latched p2 will be overwritten by addressmsb of next program address.as for movx@r0,a it shall write into
areas seperated by 256 bytes.so i think this
shall not work.what u need to do is this;
mov r0,code_msb
mov r1,code_lsb
mov r2,data_msb
mov r3,data_lsb
mov r4,#count
loop:
mov dph,r0
mov dpl,r1
clr a
movc a,@a+dptr
inc dptr
mov r0,dph
mov r1,dpl
mov dph,r2
mov dpl,r3
movx @dptr,a
inc dptr
mov r2,dph
mov r3,dpl
djnz r4,loop

as u see its a big code.but thats the problem one faces bcos of single data pntr.
bye
pranav phatak