16λ????????????·
?????1??16λ???????8088???????????????
?1 ?16λ???????8088?????????????
?????16λ???????8088?????????20????A0~A19????????A0~A7?????????D0~D7?????A16~A19???????S3~S6??????????????????????????????檔8088??洢??????Χ?1M???????????洢????????洢??????????????????λ????????????FFFF0H????????????洢???????????????????洢????С??????????????????????????????????74LS244??????
????8088???????????D0~D7?????????????????????????????74LS245??????????????????·?????????-G??????????????DEN?????????=0???74LS245??????Ч????????????DIR?????????????????????DT/-R?????????=0???????B????A??????????????????????洢????I/O????????????????
????8088??洢?????????A0~A19??????Χ?1M??I/O?????????A0~A15??????Χ?64K???洢????I/O???????????????IO/-M?????
?????2?16λ???????8086???????????????
?2 16λ???????8086?????????????
??????8088???????????????8086????????е?A0~A15?????????D0~D15???á??洢????I/O???????????????M/-IO?????
????????8088??????????????????????8λ???????洢????I/O???????????????????????????1M????洢???????64K????I/O????8086??????16λ????????????????????????????????????????????????????????????????A0??-BHE???????????????????????1 ??????????????????????????????8λ????????????????A0=0????????????????????8λ?????????????????-BHE=0???????????????????????????η???????????A0??-BHE???0?????????????????????????????η????
??1 ???????
| -BHE | A0 | ?? ?? | ???????? |
| 0 | 0 | ???????????????????? | D0~D15 |
| 1 | 0 | ?????????????????? | D0~D7 |
| 0 | 1 | ??????????????????? | D8~D15 |
0 1 | 1 0 | ???????????????????????????8λ????????8λ | D8~D15 D0~D7 |
????admin ?????????2018-05-08
