| ??? 09/19/02 13:02 Read: times |
#29372 - RE: HOW TO ACCESS 512K OF EXTERNAL MEMORY |
WHAT 8051, full ident please
MOVX @DPTR,#01h is not an instruction for the '51, please state correctly. For a 24 bit DPTR, you will need an extanded addressing device such as the Philips MX. In assembly you will need a fetch routine such as: ;; fetch ;; ;; dptr must point to 16 lsb bits of address ;; r7 must point to 8 msb bits of address ;; ;; acc contain byte fetched fetch: push p1shadow mov p1,r7 movx a,@dptr pop p1shadow ret Erik |



