5.1 80C51?????

1

• ????

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5.1 80C51?????

• 5.1.1 80C51???????

??????? CPU???????A?,???????B??CPU?????(????)
CPU?????????,??????B(?????????)
?CPU???B?????,???????A????????????A(????),????????
?
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MCS-51??????????
???
????
?????
????
????????
??
???????
????
4

• ??CPU?????,??????????CPU????????CPU?????????A,????
  ??B????B?????,???????????(???),???????????????????
  ?????(????)?

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• ??????????,????????????????????I/O?????????,??
  ???????

• ?????CPU???????I/O????,??????????

• ?????CPU???????????????,??????????

• ?????CPU???????????????????,???????????

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• ??80C51???????
• 80C51??????5????(8052? 6?) ,2????,????????? ?

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5.1.2 80C51???? ?????
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1? (P3.2)???IT0(TCON.0)??????????????????CPU??
?P3.2?????????????,????IE0(TCON.1)?1,?CPU?????
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2?(P3.3)???IT1(TCON.2)??????????????????CPU???P3
.3?????????????,????IE1(TCON.3)?1,?CPU?????
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3?TF0(TCON.5),????/???T0????????????/???T0?????
,??TF0,??CPU?????
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4?TF1(TCON.7),????/???T1????????????/???T1?????,
??TF1,??CPU?????
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5?RI(SCON.0)?TI(SCON.1),????????????????????????
??RI?????????????????TI,?CPU?????
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• ????????
• 1?TCON?????

IT0(TCON.0),????0???????? ?IT00?,???????? ?IT01?
,???????(?????)? IE0(TCON.1),????0???????? IT1(TCO
N.2),????1???????? IE1(TCON.3),????1???????? TF0(T
CON.5),??/???T0?????????? TF1(TCON.7),??/???T1????
??????
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• 2?SCON?????

• RI(SCON.0),??????????????????????,?????????,?????R
  I???,RI????????
• TI(SCON.1),????????????CPU??????????????????,?????
  ?????????????,?????TI?CPU?????,??????TI,TI????????
  

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5.1.3 80C51?????

• ????????
• CPU???????????????????????????????IE????

• EX0(IE.0),????0???
• ET0(IE.1),??/???T0?????
• EX1(IE.2),????0???
• ET1(IE.3),??/???T1?????
• ES(IE.4),????????
• EA (IE.7), CPU????(???)??

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• ?????????
• 80C51???????????,?????????????????????????
  ??????????IP???????????? ?

• PX0(IP.0),????0??????
• PT0(IP.1),??/???T0??????
• PX1(IP.2),????0??????
• PT1(IP.3),??/???T1??????
• PS (IP.4),?????????
• PT2 (IP.5) ,??/???T2???????

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?80C52???????????,????????????????????????????????
?IP?IPH???????????? ?

• PX0(IPH.0),????0??????
• PT0(IPH.1),??/???T0??????
• PX1(IPH.2),????0??????
• PT1(IPH.3),??/???T1??????
• PS (IPH.4),?????????
• PT2 (IPH.5) ,??/???T2???????

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• ????????????????,?????????????????????????,??
  ???????????????,??????

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• ??52????4????,????????T1,INT1,INT0,T0.

IPH 0X08 PT1 1
IP 0X40 PX1 1
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• 80C51??????????????

• CPU??????????,????????????????
• ??????????????????????????????
• ?????????????,??????????????

???????????,???????????????????????????????1,
?????????????,?????????????????1,????????????,???
???????????????
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5.2 80C51?????????
5.2.1 ?????????

• ????????
• ????????
• ???????????1
• CPU???(?EA1)?
• p115
• ?????,CPU?????????

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• ???????
• CPU???????,????????S5P2??,???????????????????
  ?????????????????????????
• ?????????????????S5P2?????1,??????????????????
  ???CPU???????????????LCALL??,????????????????,????
  ????????

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• ???????,?????,???LCALL??
• CPU?????????????
• ????????????????????????????????????,??????,??????
  ??????????
• ????????RET?RETI?????IE?IP????????????????????????
  ????????????

??????????????????,?????????????????,?????????
?????,????????,?????,?????????????????
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• ????????

5.2.1 ????--?????????????????????????????? (1)??
???? ?????????????? ????????????????????????
1???(??)2???(???LCALL) (2)???? ??????RET?RETI?IP?
IE??,?????????????,????8??? 2?????????(????1?????
)4???????2??????8????
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5.2.2 ??????

• ?????????????1(????????????????)?
• ??????LCALL??,???????PC?????????,?????????????????
  ?PC? (P116)
• ?????????

???????????????????????,????????????????????
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5.2.3 ????

• RETI????????
• ????????????????????????PC,CPU??????????????
• ??????????????0,??????,????????????

??,???RET????RETI???????????PUSH???POP????????,
?????????? ?
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• ??????????????,?????????CPU???????????????????
  ????????,?????CPU???????????????????????,?????????
  ????????????,??????????????????,???????????????,?
  ???????????????

????????????????????????????????????????????,?
?????8255???????????????????,??,??????????????????
?
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??????????????,???????????,?????????????????,??
??????????,??IE0?IE1????????1????CPU??????,???????
????,??CPU????????????,??????????????,???????????(
??????)????????????(????12MHz?,?1??)?
????????????????????????,?ADC0809?????????EOC????,
?????????80C51??????