TMS320F28335筆記-SCI通信

1、TMS320F28335筆記SCI通信SCI波特率存放器SCIHBAUD和SCILBAUD中設(shè)置的波特率值，將產(chǎn)生SCI內(nèi)部同步信號(hào)，輸入到發(fā)送 /接受移位存放器。SCI與CPU的接口：Figure 1-1. SCI CPU InterfaceSCI架構(gòu):全雙工LXSHFLXSHFRXSHFRXSHFSCIRXBITSCIRXBITSCISCI DevicrDevicr #1#1fiCITXDfiCITXDSCIRXDSCIRXDDSP技術(shù)應(yīng)用SCI Device #21. LSPCLK是外部輸入的時(shí)鐘信號(hào)，根據(jù)2.16級(jí)發(fā)送FIFO依次將數(shù)據(jù)傳送到數(shù)據(jù)緩沖存放器中，再進(jìn)入發(fā)送移位存放器(TX

2、SHF),按字位移位之后，再通過SCITXD引腳發(fā)送出去。3.SCIRXD是接收引腳數(shù)據(jù)從該引腳中連入接收移位存放器RXSHF,組成一個(gè)數(shù)據(jù)之后，依次進(jìn)入16級(jí)接收FIFO。4.SCITXBUF :發(fā)送數(shù)據(jù)緩沖器。包括由CPU加載、要發(fā)送出去的數(shù)據(jù)。5.TXSHF存放器：發(fā)送器移位存放器。接受來自SCITBUF存放器的數(shù)據(jù)并逐位將數(shù)據(jù)移到SCITD引腳上。6.RXSHF存放器：接收器一味存放器。逐位接受來自SCIRXD的數(shù)據(jù)并移入。7.SCIRXBUF :接收器數(shù)據(jù)緩沖存放器。包括CPU要讀的數(shù)據(jù)。來自遠(yuǎn)程處理器的數(shù)據(jù)加載到存放器RXSHF ,繼而力口載至ij SCIRXBUF和SCIRXEM

3、U。SCI數(shù)據(jù)格式：NRZ格式：One start bitOne to eight data bitsAn even/odd parity bit (optional)奇偶校驗(yàn)位One or two stop bitsAn extra bit to distinguish addresses from data (address-bit mode only)Figure 1-3. Typical SCI Data Frame FormatsfSljrtLSB234561MSB Parity Stopidle-lmp mod?(Normal nonmuttiproce&5or commu

4、nications)Address bh-111Slur I1 LS6234567MSBAddr/由話ParityI Stup1Normal nonmultiprocessor communications(普通的非多機(jī)通信)數(shù)據(jù)格式由SCICCR存放器控制：Table 14 Programming the Data Format Using SCICCRBit(s)Bit NameDesignationFunctions2-0SCI CHAR2-0SCICCR.2:0Select the character (data) length (one to eight bits).5PARITYE

5、NABLESCICCR 5Enables The party function if set io 1 or disstles the parity function if cleared to0.6EVEN/ODDPARITYSCICCR5If parity話enabledhsdects odd parity if cleared to 0 or even parity ifIo 17STOP BITSSCICCR7Determines the numr of stop bits transmitted-one slop bit if cleared to 0 cr two stophrts

6、 rt spt to 1ScibReEs.SClCCR.all =0 x0097;/ 1 slop bit. No loopback/ No parity,& cher bits,/ osync modu, idle line protocolSCI存放器：SCI-A為例:AddressRegisterName0 x007050SCICCRSCI-A通信控制存放器0 x007051SCICTL1SCI-A控制存放器10 x007052SCIHBAUDSCI-A波特單存放器，局位0 x007053SCILBAUDSCI-A波特單存放器，低位0 x007054SCICTL2SCI-A控制存

7、放器20 x007055SCIRXSTSCI-A接受狀態(tài)存放器0 x007056SCIRXEMUSCI-A接受仿真數(shù)據(jù)存放器0 x007057SCIRXBUFSCI-A接受數(shù)據(jù)存放器0 x007059SCITXBUFSCI-A發(fā)送數(shù)據(jù)存放器0 x00705ASCIFFTXSCI-A FIFO發(fā)送存放器0X00705BSCIFFRXSCI-A FIFO接受存放器0 x00705cSCIFFCTSCI-A FIFO控制存放器0 x00705FSCIPRISCI-A極性控制存放器SCI-A通信控制存放器：SCICCR:7(S545il(7(S545il(STOPSTOPETXODDETXODDPAR

8、ITYPARITYLOOPBACKLOOPBACKADAD口R R IDLEIDLESCISCISCISCISCISCIBITSBITSFARmFARmEXABLIEXABLIENABLEENABLEMODEMODECHARICHARICKAKLCKAKLCHARCHAR。0-10-1 ScopScop bitbit0 0 - - DisabledDisabled0 0 -1dk-Hn-1dk-Hn電EtotleEtotle datadata bitsbits - - (bhiai(bhiai + + 1)1)1=21=2 StopStop bitsbits1 1 = = EnabledEna

9、bled1 1 = = Addi-bitAddi-bit nodenode e.g.e.g. HOBHOB , , 7 7 datadata bitsbits0 0 = = OdaOda0 0 = = VunbledVunbled1 1 = =EYI1 -InabkdInabkdLOOP BACK ENABLE:回送使能：回送也就是將Tx引腳和Rx引腳在DSP內(nèi)部連接。ADDR/IDLE MODE:SCI多機(jī)模式控制字位，多機(jī)通信使用SLEEP和TXWAKE功能，主要使用地址位模式。而空線模式主要用于其它的通信，比方與RS232通信。SCI-A控制存放器1 SCICTL1:76543210re

10、servedRXERRINTENASW RESETresentdTXWAKESLEEPTXE5AJiXENA0 receiver dhabled1 1二recehrecehr rerer enabledenabled。=trans mitter disabled1 1 transtrans oiitteroiitter enabledenabled0 0 = = sleepsleep modemode disableddisabled1 = sleep mode euabledTransmitterTransmitter wawa keupkeup metbodmetbod selectsel

11、ect1 1 - -M M1k1k upup modemode dep-eudsdep-euds 0 0口SCICCR.3SCICCR.3 0 0 = = nono wakeupwakeup modemodeW W riterite 0 0 = = ResetReset SCISCIWriX 1 = reeiis frotu. Reset0 0 = = R R電civciv電ErrArlntt-rruptErrArlntt-rrupt disableddisabled1 1 = = RectheRecthe LrrorLrror InterruptInterrupt enabledenable

12、dSW RESET:低有效。復(fù)位到SCI狀態(tài)機(jī)和操作標(biāo)志符初始狀態(tài)。所有受影響的邏輯操作在特定的復(fù)位狀態(tài)種保持原有狀態(tài)，直到將1寫入改為。因此系統(tǒng)復(fù)位后，寫1可以重新啟動(dòng)SCI。TXWAKE與SLEEP主要用于多機(jī)通信因此，此處不作介紹。ScibRegs.SCICTLl.allScibRegs.SCICTLl.all =0 x8093;=0 x8093; / enableenable TXjTXj RXRX internalinternal SCICLKSCICLKt t/ OisakileOisakile RXRX ERR,ERR, SLEEP*SLEEP* TJCWWKETJCWWKESC

13、I-A控制存放器2 SCICTL2:SCISCI RA/BKRA/BK I?iTI?iT ENAENA-0 0 = = DisableDisable EiXRDYEiXRDY BRKDTBRKDT interruptinterrupt1 1 = = EnableEnable RXRDYRXRDY BRKDTBRKDT intertuptintertuptSCISCI TXTX EMPTYEMPTY0 0 = = TXBUTTXBUT oror shiirshiir registerregister areare loadedloaded with.with. dacadaca1 = Trans

14、mit bulfet破d獨(dú)選r east er bvch EmptySCI TX 1ST EN A-0 0 = = DisableDisable TXRDYTXRDY interruptinterrupt1 1 = = EnableEnable TXRDYTXRDY intemipfintemipfscibfteg；. SCICTL2. all三縱0093：ScibRes. SCICTL2. luit. TXINTEMA = 1：ScibRes 4 SCICTL2. bit. RXBKIMTErJA竺1：SCI-A接收狀態(tài)存放器SCIRXST:7 75 54 43 3工RXRX EKEOREK

15、EORKKKDYKKKDY3RKDT3RKDTFTFTOEOEPEPERXWAKERXWAKEreservedreserved1 = Rereivtrwakrup condidcnd-ctected1 = Farit) Error detected1 1 = = O Ovemia Error d-ftected1 - Fnming Error del-ecifd1 -Brtiil condidoti occurred 0 = no break cQuditioiL0 - co atwchiractcr io SCIKXBUF 1 - nen- ckiracter in SCIRXBKFQ =

16、N& error flags s*t 1 = Error flag) setRX ERROR:如果位RX ERR INT ENA bit (SCIDTL1.6)=1,那么該位用于中斷效勞程序過程中的快速錯(cuò)誤條件檢測(cè)。(中斷檢測(cè)、幀錯(cuò)誤、移除和極性錯(cuò)誤)RXRDY:SCI接收器就緒標(biāo)志。當(dāng)從SCIRXBUF存放器中讀一個(gè)新的字符時(shí)， 接受器將該位置1,此時(shí)，如果RX/BK INT ENA (SCICTL2.1),將產(chǎn)生一個(gè)接受中斷。通過讀SCIRXBUF存放器，或者有效的SW RESET或者系統(tǒng)復(fù)位可 使RXRDY清零。BRKDT:SCI中斷檢測(cè)標(biāo)志。當(dāng)中斷條件產(chǎn)生時(shí)，中斷條件就產(chǎn)生，在

17、一個(gè)喪失的第一個(gè)結(jié)束位后開始。FE: SCI幀錯(cuò)誤標(biāo)志。PE:極性檢測(cè)。當(dāng)檢測(cè)到1的個(gè)數(shù)與它的極性位不一致的時(shí)候置位SCI-A波特率存放器：IXIXBIFTYRXWRXWDTTIKASCISCI TXTX READYREADY0 0 = = SCnXELTSCnXELT isis fullfull1 1 = = SCTTKBITSCTTKBIT isis emptyempty7 70 05-25-2Band-SelectBand-Select MSbytt*MSbytt* RegisterRegister (SCIHBAI(SCIHBAI D)D) - - 0 x0070520 x007052

18、453210BAUD15(X1SB)BAVDLJBAVD13BAUD12BALTD11BALDISBAID9BAUDSBand-SelectBand-Select LSbyteLSbyte RegisterRegister (SCILBAUD)(SCILBAUD) - - 0 x0070530 x00705376543210BAUD7BAUDtiBAUDtiBACD5BALT-IBALT-IBALTJBALT25AIT1(LSB)SCISCI baudbaud raterate = = transmit BUF is empty,can receive new datawhile(ScibRegs.SCICTL2.bit.TXRDY != 1)/also right,but the way of tools display is differentScibRegs.SCI