?????????????????????????????
??????????????????????1??????????????? (16??)
???? ?????????????????????????????? #data/A/Rn/@Ri/direct ???????????????? 15 ?????
??????2??????????????? (4??)
????????????????????????????? RAM ??????????????? I/O ??????????????????? ???????????????????????????????????????????????䶮
????MOVX A ?? @Ri ?? A ?? ((Ri)) ???
????MOVX @Ri ?? A ?? (Ri) ???? A
????MOVX A ?? @DPTR ?? A ?? ((DPTR)) ???
????MOVX @DPTR ?? A ?? (DPTR) ???? A
?????????????????洢??????????????????????????????????????????????????????? @Ri ????????????? @DPTR ??????????????? A . ???? 4 ????䶮
??????3????????????(5??)
?????? ??? XCH A ???? byte ??
???????????????????????????е??????
????XCH ??????????????????????? A ?У?????????????????????д???????????С?????????? Rn/direct/@Ri, ?????????? A, ????????䶮
?????? 2.5 ?? RO ?????????? 20H ??????? A ????? 3FH ????? RAM ?? 20H ????????
75H ?????????? XCH A ?? @RO ????????? 20 ?? =3FH ???? A ?? =75H
?????? ??? XCHD A, @Ri
???? ??????????????????????в????? A3-0 ?????????? Ri ?? 3-0 ??
???? ?????????? A ?е?? 4 λ??????????????????????? RAM ?????? 4 λ??????н?????????????????????? 4 λ??????????λ??
???? ?? ?? RO ????? 20H ???????????? 36H ????? RAM ?? 20H ???????? 75H ?????????? XCHD A ?? @RO
???? ????? ?? 20H ?? =0111011=76H
?????????????? ?? A ?? =00110101B=35H
???? ?? ??? SWAP A
????A ?????λ???????λ??????
?????? : ?? A ????? 36H ???? SWAP A ?? A ? 63H
?? ??3????????
???? ?? ??? PUSH direct ????????????м?????????????????????
???? ?????????????????? 1 ????У? SP ?????? SP ?? +1 ?????????????е????? ???????????????? direct ??????????????? SP ???????????У???У? SP ?????? direct ???????????λ??
???? ?? ???????? 09H ?????????????? 0123H ?????????????????н????
????PUSH DPL
????PUSH DPH
??????н??????? 0AH ?? =23H ??
?????????????????? 0BH ?? =01H ???? SP ?? =0BH
?????? ??? POP direct ??????????е??м????????????????????????
???? ?????????????????????? RAM ?????????????????????????????????????????? 1 ??????в?????
???? ?? direct ???? ((SP)),(SP) ?? (SP)-1; ?????в??????λ??
???? ?? ?裨 SP ?? =32H ????? RAM ?? 31H ??32H ????е???????? 23H ?? 01H ?????????????????н????
???? POP DPH
???? POP DPL
???? ??н????? DPTR ?? =0123H,
???????????????????? (SP) =30H ??
??????????????????
???? ??1??????????
???? LJMP ??????
???? ???????????????????洢?? 64KB ?????κε????
???? ??2????????????
???? AJMP ??????
???? ???? 4002H LJMP MM
???? ????
???? 4600H MM ?? MOV A ?? #00H
???? ???????????????????????? 51 ??????У? 64KB ????洢????? 32 ????? 2KB(7FFH) ??
???? ??3??????????
???? SJMP ?????? (rel)
???? ????
???? 4060H SJMP LOOP
???? ????
???? 4090H LOOP ?? MOV A ?? #0FFH
???? ????
???? ???????????????????????????????? 127 ?? 7FH ????????? 128 ?? 80H ??????????????г??????????????
???? ??4???? 1 ????????????
???? DJNZ Rn ??????? (rel) ????? (Rn)-1 ?? 0 ????????????????????????????????????
???? DJNZ direct, ????? (rel) ????? (direct)-1 ?? 0 ????????????????????????????????????
???? ?? : ?? 8031 ??? RAM ?? 40H~4FH ????ó?? A0H~AFH ?????????
????MOV RO ?? #40H ?? RO ??????????????
????MOV R2 ?? #10H ?? R2 ???????????????
????MOV A ?? #0A0H ?? A ???
????LOOP ?? MOV @ RO ?? A ?????????
????INC ?? RO ??????????
????INC A ????????????
????DJNZ R2 ?? LOOP ??δ?????????????????
????RET ????????????
????admin ?????????2018-05-08
