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        Freescale 9S12 系列單片機(jī)應(yīng)用筆記（SCI）2
        
						
        
				作者：
				時(shí)間：2016-11-20
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			這里給個(gè)利用串口收發(fā)中斷的實(shí)現(xiàn).
        本文引用地址：http://www.104case.com/article/201611/318824.htm
        首先是頭文件:
        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. }

        最后給個(gè)例子說(shuō)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. 例子很簡(jiǎn)單，就不多解釋了。
        下一篇介紹在實(shí)時(shí)操作系統(tǒng) uC/OS-II 上實(shí)現(xiàn)串口驅(qū)動(dòng)。
        
				
            
                
			
							
        
                
			              
              
            
        
		
        
		
        
		
        
		
        
		
        
			
          
				
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