Freescale 9S12 系列单片机应用笔记（SCI）3

时间：11-20 来源：互联网点击：

这次介绍如何在 uC/OS-II 上实现串口驱动。

/*sci_ucos.h*/
#ifndef_SCI_RTOS_H_
#define_SCI_RTOS_H_
#defineSCI_RX_BUF_SIZE64/*NumberofcharactersinRxringbuffer*/
#defineSCI_TX_BUF_SIZE64/*NumberofcharactersinTxringbuffer*/
/*
*********************************************************************************************************
*CONSTANTS
*********************************************************************************************************
*/
#ifndefNUL
#defineNUL0x00
#endif
/*ERRORCODES*/
#defineSCI_NO_ERR0/*Functioncallwassuccessful*/
#defineSCI_BAD_CH1/*Invalidcommunicationsportchannel*/
#defineSCI_RX_EMPTY2/*Rxbufferisempty,nocharacteravailable*/
#defineSCI_TX_FULL3/*Txbufferisfull,couldnotdepositcharacter*/
#defineSCI_TX_EMPTY4/*IftheTxbufferisempty.*/
#defineSCI_RX_TIMEOUT5/*Ifatimeoutoccurredwhilewaitingforacharacter*/
#defineSCI_TX_TIMEOUT6/*Ifatimeoutoccurredwhilewaitingtosendachar.*/
#defineSCI_PARITY_NONE0/*Definesforsettingparity*/
#defineSCI_PARITY_ODD1
#defineSCI_PARITY_EVEN2
/*
*********************************************************************************************************
*DATATYPES
*********************************************************************************************************
*/
typedefstruct{
shortRingBufRxCtr;/*NumberofcharactersintheRxringbuffer*/
OS_EVENT*RingBufRxSem;/*PointertoRxsemaphore*/
unsignedchar*RingBufRxInPtr;/*Pointertowherenextcharacterwillbeinserted*/
unsignedchar*RingBufRxOutPtr;/*Pointerfromwherenextcharacterwillbeextracted*/
unsignedcharRingBufRx[SCI_RX_BUF_SIZE];/*Ringbuffercharacterstorage(Rx)*/
shortRingBufTxCtr;/*NumberofcharactersintheTxringbuffer*/
OS_EVENT*RingBufTxSem;/*PointertoTxsemaphore*/
unsignedchar*RingBufTxInPtr;/*Pointertowherenextcharacterwillbeinserted*/
unsignedchar*RingBufTxOutPtr;/*Pointerfromwherenextcharacterwillbeextracted*/
unsignedcharRingBufTx[SCI_TX_BUF_SIZE];/*Ringbuffercharacterstorage(Tx)*/
}SCI_RING_BUF;
/**
*Toobtainacharacterfromthecommunicationschannel.
*@paramport,portcanbeSCI0/SCI1
*@paramto,istheamountoftime(inclockticks)thatthecallingfunctioniswillingto
*waitforacharactertoarrive.Ifyouspecifyatimeoutof0,thefunctionwill
*waitforeverforacharactertoarrive.
*@paramerr,isapointertowhereanerrorcodewillbeplaced:
**errissettoSCI_NO_ERRifacharacterhasbeenreceived
**errissettoSCI_RX_TIMEOUTifatimeoutoccurred
**errissettoSCI_BAD_CHifyouspecifyaninvalidchannelnumber
*@returnThecharacterinthebuffer(orNULifatimeoutoccurred)
*/
unsignedcharSCIGetCharB(unsignedcharch,unsignedshortto,unsignedchar*err);
/**
*Thisfunctioniscalledbyyourapplicationtosendacharacteronthecommunications
*channel.Thefunctionwillwaitforthebuffertoemptyoutifthebufferisfull.
*Thefunctionreturnstoyourapplicationifthebufferdoesntemptywithinthespecified
*timeout.Atimeoutvalueof0meansthatthecallingfunctionwillwaitforeverforthe
*buffertoemptyout.ThecharactertosendisfirstinsertedintotheTxbufferandwill
*besentbytheTxISR.Ifthisisthefirstcharacterplacedintothebuffer,theTxISR
*willbeenabled.
*
*@paramport,portcanbeSCI0/SCI1
*@paramcisthecharactertosend.
*@paramtoisthetimeout(inclockticks)towaitincasethebufferisfull.Ifyou
*specifyatimeoutof0,thefunctionwillwaitforeverforthebuffertoempty.
*@returnSCI_NO_ERRifthecharacterwasplacedintheTxbuffer
*SCI_TX_TIMEOUTifthebufferdidntemptywithinthespecifiedtimeoutperiod
*SCI_BAD_CHifyouspecifyaninvalidchannelnumber
*/
unsignedcharSCIPutCharB(unsignedcharport,unsignedcharc,unsignedshortto);
/**
*Toinitializethecommunicationsmodule.
*Youmustcallthisfunctionbeforecallinganyotherfunctions.
*/
voidSCIBufferInit(void);
/**
*Toseeifanycharacterisavailablefromthecommunicationschannel.
*
*@paramport,portcanbeSCI0/SCI1
*@returnIfatleaston

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