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Freescale 9S12 系列单片机使用笔记（SCI）2

2020年9月18日 15:00 阅读(220)

这里给个利用串口收发中断的实现.首先是头文件:/*sci_buffered.h*/p>#ifndef_SCI_BUFFERED_H_#define_SCI_BUFFERED_H_/p>p&

这儿给个使用串口收发中止的完成.

首先是头文件:

  1. /*sci_buffered.h*/

  2. #ifndef_SCI_BUFFERED_H_

  3. #define_SCI_BUFFERED_H_

    #defineSCI_RX_BUF_SIZE64/*NumberofcharactersinRxringbuffer*/

  4. #defineSCI_TX_BUF_SIZE64/*NumberofcharactersinTxringbuffer*/

    #defineSCI_NO_ERR0/*Functioncallwassuccessful*/

  5. #defineSCI_BAD_CH1/*Invalidcommunicationsportchannel*/
  6. #defineSCI_RX_EMPTY2/*Rxbufferisempty,nocharacteravailable*/
  7. #defineSCI_TX_FULL3/*Txbufferisfull,couldnotdepositcharacter*/
  8. #defineSCI_TX_EMPTY4/*IftheTxbufferisempty.*/

  9. /**
  10. *Toobtainacharacterfromthecommunicationschannel.
  11. *@paramport,portcanbeSCI0/SCI1
  12. *@paramerr,isapointertowhereanerrorcodewillbeplaced:
  13. **errissettoSCI_NO_ERRifacharacterisavailable
  14. **errissettoSCI_RX_EMPTYiftheRxbufferisempty
  15. **errissettoSCI_BAD_CHifyouhavespecifiedaninvalidchannel
  16. *@returnThereceivedchariferr==SCI_NO_ERR
  17. */
  18. unsignedcharSCIGetCharB(unsignedcharport,unsignedchar*err);

    /**

  19. *Tosendacharacteronthecommunicationschannel.
  20. *ThecharactertosendisfirstinsertedintotheTxbufferandwillbesentby
  21. *theTxISR.Ifthisisthefirstcharacterplacedintothebuffer,theTxISRwillbe
  22. *enabled.IftheTxbufferisfull,thecharacterwillnotbesent(i.e.itwillbelost)
  23. *
  24. *@paramport,portcanbeSCI0/SCI1
  25. *@returnCOMM_NO_ERRifthefunctionwassuccessful(thebufferwasnotfull)
  26. *COMM_TX_FULLifthebufferwasfull
  27. *COMM_BAD_CHifyouhavespecifiedanincorrectchannel
  28. */
  29. unsignedcharSCIPutCharB(unsignedcharport,unsignedcharc);

    /**

  30. *Toinitializethecommunicationsmodule.
  31. *Youmustcallthisfunctionbeforecallinganyotherfunctions.
  32. */
  33. voidSCIBufferInit(void);

    /**

  34. *Toseeifanycharacterisavailablefromthecommunicationschannel.
  35. *
  36. *@paramport,portcanbeSCI0/SCI1
  37. *@returnIfatleastonecharacterisavailable,thefunctionreturns
  38. *FALSE(0)otherwise,thefunctionreturnsTRUE(1).
  39. */
  40. unsignedcharSCIBufferIsEmpty(unsignedcharport);

    /**

  41. *ToseeifanymorecharacterscanbeplacedintheTxbuffer.
  42. *Inotherwords,thisfunctionchecktoseeiftheTxbufferisfull.
  43. *
  44. *@paramport,portcanbeSCI0/SCI1
  45. *@returnIfthebufferisfull,thefunctionreturnsTRUE
  46. *otherwise,thefunctionreturnsFALSE.
  47. */
  48. unsignedcharSCIBufferIsFull(unsignedcharport);

    #endif

然后 是 c 文件.

  1. /**

  2. *SCI(SerialCommunicationInterface)BufferedSerialI/O
  3. *@filesci_buffered.c
  4. *@authorLiYuan
  5. *@platformmc9s12XX
  6. *@date2012-7-22
  7. *@version1.0.1
  8. */

  9. #include”derivative.h”/*derivative-specificdefinitions*/
  10. #include
  11. #include”sci.h”
  12. #include”sci_buffered.h”

    //#defineOS_ENTER_CRITICAL()_asm(“pshc;sei”)

  13. //#defineOS_EXIT_CRITICAL()_asm(“pulc”)

    #defineOS_ENTER_CRITICAL()_asm(“tpa;sei;staacpu_sr”)

  14. #defineOS_EXIT_CRITICAL()_asm(“ldaacpu_sr;tap”)

    /**

  15. *DATATYPES
  16. */
  17. typedefstruct{
  18. shortRingBufRxCtr;/*NumberofcharactersintheRxringbuffer*/
  19. unsignedchar*RingBufRxInPtr;/*Pointertowherenextcharacterwillbeinserted*/
  20. unsignedchar*RingBufRxOutPtr;/*Pointerfromwherenextcharacterwillbeextracted*/
  21. unsignedcharRingBufRx[SCI_RX_BUF_SIZE];/*Ringbuffercharacterstorage(Rx)*/
  22. shortRingBufTxCtr;/*NumberofcharactersintheTxringbuffer*/
  23. unsignedchar*RingBufTxInPtr;/*Pointertowherenextcharacterwillbeinserted*/
  24. unsignedchar*RingBufTxOutPtr;/*Pointerfromwherenextcharacterwillbeextracted*/
  25. unsignedcharRingBufTx[SCI_TX_BUF_SIZE];/*Ringbuffercharacterstorage(Tx)*/
  26. }SCI_RING_BUF;

    /**

  27. *GLOBALVARIABLES
  28. */

    SCI_RING_BUFSCI0Buf;

  29. SCI_RING_BUFSCI1Buf;

  30. /**
  31. *Toobtainacharacterfromthecommunicationschannel.
  32. *@paramport,portcanbeSCI0/SCI1
  33. *@paramerr,isapointertowhereanerrorcodewillbeplaced:
  34. **errissettoSCI_NO_ERRifacharacterisavailable
  35. **errissettoSCI_RX_EMPTYiftheRxbufferisempty
  36. **errissettoSCI_BAD_CHifyouhavespecifiedaninvalidchannel
  37. *@returnThereceivedchariferr==SCI_NO_ERR
  38. */
  39. unsignedcharSCIGetCharB(unsignedcharport,unsignedchar*err)
  40. {
  41. unsignedcharcpu_sr;
  43. unsignedcharc;
  44. SCI_RING_BUF*pbuf;
  46. /*Obtainpointertocommunicationschannel*/
  47. switch(port)
  48. {
  49. caseSCI0:
  50. pbuf=&SCI0Buf;
  51. break;

    caseSCI1:

  52. pbuf=&SCI1Buf;
  53. break;

    default:

  54. *err=SCI_BAD_CH;
  55. return(0);
  56. }
  57. OS_ENTER_CRITICAL();
  58. if(pbuf->RingBufRxCtr>0)/*Seeifbufferisempty*/
  59. {
  60. pbuf->RingBufRxCtr–;/*No,decrementcharactercount*/
  61. c=*pbuf->RingBufRxOutPtr++;/*Getcharacterfrombuffer*/
  62. if(pbuf->RingBufRxOutPtr==&pbuf->RingBufRx[SCI_RX_BUF_SIZE])
  63. {
  64. pbuf->RingBufRxOutPtr=&pbuf->RingBufRx[0];/*WrapOUTpointer*/
  65. }
  66. OS_EXIT_CRITICAL();
  67. *err=SCI_NO_ERR;
  68. return(c);
  69. }
  70. else
  71. {
  72. OS_EXIT_CRITICAL();
  73. *err=SCI_RX_EMPTY;
  74. c=0;/*Bufferisempty,return0*/
  75. return(c);
  76. }
  77. }

  78. /**
  79. *Tosendacharacteronthecommunicationschannel.
  80. *ThecharactertosendisfirstinsertedintotheTxbufferandwillbesentby
  81. *theTxISR.Ifthisisthefirstcharacterplacedintothebuffer,theTxISRwillbe
  82. *enabled.IftheTxbufferisfull,thecharacterwillnotbesent(i.e.itwillbelost)
  83. *
  84. *@paramport,portcanbeSCI0/SCI1
  85. *@returnCOMM_NO_ERRifthefunctionwassuccessful(thebufferwasnotfull)
  86. *COMM_TX_FULLifthebufferwasfull
  87. *COMM_BAD_CHifyouhavespecifiedanincorrectchannel
  88. */
  89. unsignedcharSCIPutCharB(unsignedcharport,unsignedcharc)
  90. {
  91. unsignedcharcpu_sr;
  93. SCI_RING_BUF*pbuf;
  95. /*Obtainpointertocommunicationschannel*/
  96. switch(port)
  97. {
  98. caseSCI0:
  99. pbuf=&SCI0Buf;
  100. break;

    caseSCI1:

  101. pbuf=&SCI1Buf;
  102. break;

    default:

  103. return(SCI_BAD_CH);
  104. }

    OS_ENTER_CRITICAL();

  105. if(pbuf->RingBufTxCtr
  106. {
  107. pbuf->RingBufTxCtr++;/*No,incrementcharactercount*/
  108. *pbuf->RingBufTxInPtr++=c;/*Putcharacterintobuffer*/
  109. if(pbuf->RingBufTxInPtr==&pbuf->RingBufTx[SCI_TX_BUF_SIZE])
  110. {
  111. pbuf->RingBufTxInPtr=&pbuf->RingBufTx[0];/*WrapINpointer*/
  112. }
  113. if(pbuf->RingBufTxCtr==1)
  114. {/*Seeifthisisthefirstcharacter*/
  115. SCIEnableTxInt(port);/*Yes,EnableTxinterrupts*/
  116. OS_EXIT_CRITICAL();
  117. }
  118. else
  119. {
  120. OS_EXIT_CRITICAL();
  121. }
  122. return(SCI_NO_ERR);
  123. }
  124. else
  125. {
  126. OS_EXIT_CRITICAL();
  127. return(SCI_TX_FULL);
  128. }
  129. }

    /**

  130. *Toinitializethecommunicationsmodule.
  131. *Youmustcallthisfunctionbeforecallinganyotherfunctions.
  132. */
  133. voidSCIBufferInit(void)
  134. {
  135. SCI_RING_BUF*pbuf;
  137. /*InitializetheringbufferforSCI0*/
  138. pbuf=&SCI0Buf;
  139. pbuf->RingBufRxCtr=0;
  140. pbuf->RingBufRxInPtr=&pbuf->RingBufRx[0];
  141. pbuf->RingBufRxOutPtr=&pbuf->RingBufRx[0];
  142. pbuf->RingBufTxCtr=0;
  143. pbuf->RingBufTxInPtr=&pbuf->RingBufTx[0];
  144. pbuf->RingBufTxOutPtr=&pbuf->RingBufTx[0];
  146. /*InitializetheringbufferforSCI1*/
  147. pbuf=&SCI1Buf;
  148. pbuf->RingBufRxCtr=0;
  149. pbuf->RingBufRxInPtr=&pbuf->RingBufRx[0];
  150. pbuf->RingBufRxOutPtr=&pbuf->RingBufRx[0];
  151. pbuf->RingBufTxCtr=0;
  152. pbuf->RingBufTxInPtr=&pbuf->RingBufTx[0];
  153. pbuf->RingBufTxOutPtr=&pbuf->RingBufTx[0];
  154. }

  155. /**
  156. *Toseeifanycharacterisavailablefromthecommunicationschannel.
  157. *
  158. *@paramport,portcanbeSCI0/SCI1
  159. *@returnIfatleastonecharacterisavailable,thefunctionreturns
  160. *FALSE(0)otherwise,thefunctionreturnsTRUE(1).
  161. */
  162. unsignedcharSCIBufferIsEmpty(unsignedcharport)
  163. {
  164. unsignedcharcpu_sr;
  165. unsignedcharempty;
  166. SCI_RING_BUF*pbuf;
  168. /*Obtainpointertocommunicationschannel*/
  169. switch(port)
  170. {
  171. caseSCI0:
  172. pbuf=&SCI0Buf;
  173. break;

    caseSCI1:

  174. pbuf=&SCI1Buf;
  175. break;

    default:

  176. return(1);
  177. }
  178. OS_ENTER_CRITICAL();
  179. if(pbuf->RingBufRxCtr>0)/*Seeifbufferisempty*/
  180. {
  181. empty=0;/*BufferisNOTempty*/
  182. }
  183. else
  184. {
  185. empty=1;/*Bufferisempty*/
  186. }
  187. OS_EXIT_CRITICAL();
  188. return(empty);
  189. }

  190. /**
  191. *ToseeifanymorecharacterscanbeplacedintheTxbuffer.
  192. *Inotherwords,thisfunctionchecktoseeiftheTxbufferisfull.
  193. *
  194. *@paramport,portcanbeSCI0/SCI1
  195. *@returnIfthebufferisfull,thefunctionreturnsTRUE
  196. *otherwise,thefunctionreturnsFALSE.
  197. */
  198. unsignedcharSCIBufferIsFull(unsignedcharport)
  199. {
  200. unsignedcharcpu_sr;
  202. charfull;
  203. SCI_RING_BUF*pbuf;
  205. /*Obtainpointertocommunicationschannel*/
  206. switch(port)
  207. {
  208. caseSCI0:
  209. pbuf=&SCI0Buf;
  210. break;

    caseSCI1:

  211. pbuf=&SCI1Buf;
  212. break;

    default:

  213. return(1);
  214. }
  215. OS_ENTER_CRITICAL();
  216. if(pbuf->RingBufTxCtr
  217. {/*Seeifbufferisfull*/
  218. full=0;/*BufferisNOTfull*/
  219. }
  220. else
  221. {
  222. full=1;/*Bufferisfull*/
  223. }
  224. OS_EXIT_CRITICAL();
  225. return(full);
  226. }

  227. //ThisfunctioniscalledbytheRxISRtoinsertacharacterintothereceiveringbuffer.
  228. staticvoidSCIPutRxChar(unsignedcharport,unsignedcharc)
  229. {
  230. SCI_RING_BUF*pbuf;
  231. /*Obtainpointertocommunicationschannel*/
  232. switch(port)
  233. {
  234. caseSCI0:
  235. pbuf=&SCI0Buf;
  236. break;

    caseSCI1:

  237. pbuf=&SCI1Buf;
  238. break;

    default:

  239. return;
  240. }
  241. if(pbuf->RingBufRxCtr
  242. {
  243. pbuf->RingBufRxCtr++;/*No,incrementcharactercount*/
  244. *pbuf->RingBufRxInPtr++=c;/*Putcharacterintobuffer*/
  245. if(pbuf->RingBufRxInPtr==&pbuf->RingBufRx[SCI_RX_BUF_SIZE])
  246. {/*WrapINpointer*/
  247. pbuf->RingBufRxInPtr=&pbuf->RingBufRx[0];
  248. }
  249. }
  250. }

  251. //ThisfunctioniscalledbytheTxISRtoextractthenextcharacterfromtheTxbuffer.
  252. //ThefunctionreturnsFALSEifthebufferisemptyafterthecharacterisextractedfrom
  253. //thebuffer.ThisisdonetosignaltheTxISRtodisableinterruptsbecausethisisthe
  254. //lastcharactertosend.
  255. staticunsignedcharSCIGetTxChar(unsignedcharport,unsignedchar*err)
  256. {
  257. unsignedcharc;
  258. SCI_RING_BUF*pbuf;

    switch(port)

  259. {
  260. caseSCI0:
  261. pbuf=&SCI0Buf;
  262. break;

    caseSCI1:

  263. pbuf=&SCI1Buf;
  264. break;

    default:

  265. *err=SCI_BAD_CH;
  266. return(0);
  267. }
  269. /*Seeifbufferisempty*/
  270. if(pbuf->RingBufTxCtr>0)
  271. {
  272. pbuf->RingBufTxCtr–;/*No,decrementcharactercount*/
  273. c=*pbuf->RingBufTxOutPtr++;/*Getcharacterfrombuffer*/
  274. if(pbuf->RingBufTxOutPtr==&pbuf->RingBufTx[SCI_TX_BUF_SIZE])
  275. {
  276. pbuf->RingBufTxOutPtr=&pbuf->RingBufTx[0];/*WrapOUTpointer*/
  277. }
  278. *err=SCI_NO_ERR;
  279. return(c);/*Charactersarestillavailable*/
  280. }else{
  281. *err=SCI_TX_EMPTY;
  282. return(0);/*Bufferisempty*/
  283. }
  284. }

  285. interruptVectorNumber_Vsci0voidSCI0_ISR(void)
  286. {
  287. charstatus;
  288. unsignedchardata;
  289. unsignedcharerr;
  290. status=SCI0SR1;
  292. if(status&0x0F)//0x1F=00011111,ifstatusisnotReceiveDataRegFullFlag
  293. {
  294. //Seeifwehavesomekindoferror
  295. //Clearinterrupt(donothingaboutit!)
  296. data=SCI0DRL;
  297. }
  298. elseif(status&0x20)//ReceiveDataRegFullFlag
  299. {
  300. data=SCI0DRL;
  301. SCIPutRxChar(SCI0,data);//Insertreceivedcharacterintobuffer
  302. }
  303. elseif(status&0x80)
  304. {
  305. data=SCIGetTxChar(SCI0,&err);//Getnextcharactertosend.
  306. if(err==SCI_TX_EMPTY)
  307. {//Dowehaveanymorecharacterstosend?
  308. //No,DisableTxinterrupts
  309. SCI0CR2_SCTIE=0;
  310. SCI0CR2_TCIE=0;
  311. }
  312. else
  313. {
  314. SCI0DRL=data;//Yes,Sendcharacter
  315. }
  316. }
  317. }

    interruptVectorNumber_Vsci1voidSCI1_ISR(void)

  318. {
  319. charstatus;
  320. unsignedchardata;
  321. unsignedcharerr;
  322. status=SCI1SR1;
  324. if(status&0x0F)//0x1F=00011111,ifstatusisnotReceiveDataRegFullFlag
  325. {
  326. //Seeifwehavesomekindoferror
  327. //Clearinterrupt(donothingaboutit!)
  328. data=SCI1DRL;
  329. }
  330. elseif(status&0x20)//ReceiveDataRegFullFlag
  331. {
  332. data=SCI1DRL;
  333. SCIPutRxChar(SCI1,data);//Insertreceivedcharacterintobuffer
  334. }
  335. elseif(status&0x80)
  336. {
  337. data=SCIGetTxChar(SCI1,&err);//Getnextcharactertosend.
  338. if(err==SCI_TX_EMPTY)
  339. {//Dowehaveanymorecharacterstosend?
  340. //No,DisableTxinterrupts
  341. SCI1CR2_SCTIE=0;
  342. SCI1CR2_TCIE=0;
  343. }
  344. else
  345. {
  346. SCI1DRL=data;//Yes,Sendcharacter
  347. }
  348. }
  349. }

最终给个比如阐明用法:

  1. #include/*commondefinesandmacros*/
  2. #include”derivative.h”/*derivative-specificdefinitions*/
  3. #include”sci.h”
  4. #include”sci_buffered.h”

  6. voidmain(void)

  7. {
  8. /*putyourowncodehere*/
  9. unsignedcharC,err;
  10. longl=0x1234L;
  11. inti=0x5678;
  12. CRGInit();
  13. SCIInit(SCI0);
  14. SCIInit(SCI1);
  15. SCIBufferInit();
  16. SCISetIEBit(SCI0,SCI_RIE);
  17. SCISetIEBit(SCI1,SCI_RIE);

    EnableInterrupts;

  18. SCIPutShortBigEndian(SCI1,i);
  19. SCIPutShortLittleEndian(SCI1,i);
  21. SCIPutLongBigEndian(SCI1,l);
  22. SCIPutLongLittleEndian(SCI1,l);
  23. for(;;)
  24. {
  25. _FEED_COP();/*feedsthedog*/
  26. C=SCIGetCharB(SCI1,&err);
  27. if(err==SCI_NO_ERR)
  28. {
  29. SCIPutCharB(SCI1,C);
  30. }
  31. }/*loopforever*/
  32. /*pleasemakesurethatyouneverleavemain*/
  33. }

  34. 比如很简单，就不多解说了。

下一篇介绍在实时操作系统 uC/OS-II 上完成串口驱动。

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