单元八串行通讯接口ppt课件

1、32-Bit-Digital Signal ControllerTMS320F2812Transmitter-databuffer registerTransmittershift registerSCI Device #1SCIRXDSCITXDSCITXDSCIRXDSCI Device #28Receiver-databuffer registerReceivershift register8Transmitter-databuffer registerTransmittershift register8Receiver-databuffer registerReceivershift

2、register8(Full Duplex Shown)RX FIFO_0RX FIFO_15RX FIFO_0RX FIFO_15TX FIFO_0TX FIFO_15TX FIFO_0TX FIFO_15StartLSB23457MSBParityStop 1Addr/Data6该位只需在地址位方式出现该位只需在地址位方式出现Stop 2NRZ (nonreturn to zero) formatStart BitLSB of DataMajorityVote下降沿检测SCIRXDSCICLK(Internal)123456781234567812Note: 8 SCICLK 每个数据位L

3、ast DataST SPSTDataSCIRXD/SCITXD帧的一个块 SPSPLast DataSTAddr SP10位或更多空闲周期10位或更多的空闲周期地址帧跟随在10位或更多空闲周期后块中的第一帧 SPSTAddr空闲周期少于10位Last DataSTSTDataSCIRXD/SCITXDBlock of Frames SPSPLast DataSTAddr SP无重要性的空闲周期长度块中的首个帧是地址.地址位(ADDR/DATA)为1第一个数据帧0100 SPSTAddr1SP停顿位外无需额外的空闲位AddressRegisterName0 x007050SCICCRSCI-A

4、 commun. control register0 x007051SCICTL1SCI-A control register 10 x007052SCIHBAUDSCI-A baud register, high byte0 x007053SCILBAUDSCI-A baud register, low byte0 x007054SCICTL2SCI-A control register 2 register0 x007055SCIRXSTSCI-A receive status register0 x007056SCIRXEMUSCI-A receive emulation data bu

5、ffer0 x007057SCIRXBUFSCI-A receive data buffer register0 x007059SCITXBUFSCI-A transmit data buffer register0 x00705ASCIFFTXSCI-A FIFO transmit register0 x00705BSCIFFRXSCI-A FIFO receive register0 x00705CSCIFFCTSCI-A FIFO control register0 x00705FSCIPRISCI-A priority control registerADDR/IDLEMODESTOP

6、BITSEVEN/ODDPARITYPARITYENABLELOOP BACKENABLESCICHAR2SCICHAR1SCICHAR0Communications Control Register (SCICCR) 0 x007050终了位个数终了位个数0 = 1 终了位终了位1 = 2 终了位终了位偶偶/奇极性选择奇极性选择0 = 奇极性奇极性1 = 偶极性偶极性SCI极性使能极性使能0 = Disabled1 = Enabled回送测试方式回送测试方式使能位使能位0 = Disabled1 = Enabled多处置方式控制位多处置方式控制位0 = 空闲线方式空闲线方式1 = 地址位方式

7、地址位方式76543210字符长度控制位字符长度控制位# of data bits = (binary + 1)e.g. 110b gives 7 data bitsSCI-B Communications Control Register (SCICCR) 0 x007750TXWAKEreservedRX ERRINT ENASWRESETreservedSLEEPTXENARXENAControl Register 1 (SCICTL1) 0 x007051接纳中断使能位接纳中断使能位0 = 制止接纳错误中断制止接纳错误中断1 = 启动接纳错误中断启动接纳错误中断SCI 软件复位软件复位

8、Write 0 = Reset SCIWrite 1 = release from ResetSCI发送器以唤醒方式选择控制位发送器以唤醒方式选择控制位1 = 所选择的发送特征依赖于所选择的发送特征依赖于 SCICCR.3 指定的方式指定的方式0 = no wakeup mode 76543210SCI-B Control Register 1 (SCICTL1) 0 x007751SCI睡眠使能位睡眠使能位0 = sleep mode disabled1 = sleep mode enabledSCI发送器使能发送器使能0 = transmitter disabled1 = transmit

9、ter enabledSCI 接纳器使能接纳器使能0 = receiver disabled1 = receiver enabledBAUD15(MSB)BAUD14Baud-Select MSbyte Register (SCIHBAUD) 0 x00705276543210BAUD13BAUD12BAUD11BAUD10BAUD9BAUD8BAUD6Baud-Select LSbyte Register (SCILBAUD) 0 x00705376543210BAUD5BAUD4BAUD3BAUD2BAUD1BAUD7BAUD0(LSB)SCI baud rate =LSPCLK(BRR

10、+ 1) x 8LSPCLK16,BRR = 1 to 65535,BRR = 0SCI-B Baud-Select MSbyte Register (SCIHBAUD) 0 x007752SCI-B Baud-Select LSbyte Register (SCILBAUD) 0 x007753TXRDYTX EMPTYRX/BKINT ENA0TXINT ENA1765 - 2reserved发送器缓冲发送器缓冲存放器就绪标志存放器就绪标志SCI TX READY 0 = SCITXBUF 满满 1 = SCITXBUF空，预备接纳下一个字符空，预备接纳下一个字符发送器空标志发送器空标志S

11、CI TX EMPTY0 = 发送缓冲发送缓冲TXBUF或移位存放器都装载了数据或移位存放器都装载了数据 1 = 发送缓冲存放器和移位存放器都空发送缓冲存放器和移位存放器都空reserved15 - 8SCI-B Control Register 2(SCICTL2) 0 x007754SCITXBUF存放器中断使能位存放器中断使能位SCI TX INT ENA 0 = Disable TXRDY interrupt 1 = Enable TXRDY interrupt接纳器缓冲接纳器缓冲/中断使能中断使能SCI RX/BK INT ENA 0 = Disable RXRDY/BRKDT in

12、terrupt 1 = Enable RXRDY/BRKDT interruptSCI-B Receiver Status Register (SCIRXST) 0 x007755OERXERRORRXRDYBRKDTFEPERXWAKEreserved接纳器错误标志位接纳器错误标志位0 = No error flags set1 = Error flag(s) set接纳器就绪标志位接纳器就绪标志位0 = SCIRXBUF中无新的字符中无新的字符1 = SCIRXBUF有新的字符预备被读入有新的字符预备被读入SCI中断检测标志位中断检测标志位1 = 中断条件产生中断条件产生0 = 无中断条件

13、产生无中断条件产生 76543210帧错误标志帧错误标志1 = 检测到帧错误检测到帧错误溢出错误标志溢出错误标志1 = 检测到溢出错误检测到溢出错误奇偶极性错误标志奇偶极性错误标志1 = 检测到奇偶极性错误检测到奇偶极性错误接纳器唤醒检测标志接纳器唤醒检测标志1 = 检测到接纳器唤醒条检测到接纳器唤醒条件件0TXFFIL2SCIFFENATXFFST0TXFFST3TXFFIENA123456789101112131415TXFFIL0TXFFIL1TXFFIL4TXFFIL3TXFFST1TXFFINTCLRTXFFST2TXFFINTTXFFST4TXFIFORESETSCIRSTTX F

14、IFO 形状形状 (read-only)00000TX FIFO 空空00001TX FIFO 有有 1 word00010TX FIFO 有有 2 words00011TX FIFO 有有 3 words10000TX FIFO 有有 16 words.TX FIFO 中断级位中断级位TXFFST4-0与与TXFFIL4-0匹配是产生中断匹配是产生中断SCI FIFO加强型功能使能位加强型功能使能位0 = disable1 = enableTX FIFO 复位复位0 = 复位后复位后FIFO 指针为指针为01 = 重新使能操作重新使能操作TX FIFO中断使能中断使能0 = 制止基于制止基于

15、TXFFIVL匹配的中断匹配的中断1 = 使能基于使能基于TXFFIVL匹配的中断匹配的中断TX FIFO中断标志位中断标志位 (read-only)0 = not occurred1 = occurredTX FIFO中断标志清零位中断标志清零位0 = no effect1 = clearSCI 复位复位0 = reset1 = enable operation0RXFFIL2RXFF-OVF CLRRXFFST0RXFFST3RXFFIEN123456789101112131415RXFFIL0RXFFIL1RXFFIL4 RXFFIL3RXFFST1RXFFINTCLRRXFFST2RX

16、FFINTRXFFST4RXFIFORESETRXFF-OVFRX FIFO 形状形状s (read-only)00000RX FIFO 空空00001RX FIFO 有有 1 word00010RX FIFO 有有 2 words00011RX FIFO 有有 3 words10000RX FIFO 有有 16 words.RX FIFO 中断级位中断级位RXFFST4-0与与 RXFFIL4-0 匹配是产生中断匹配是产生中断RX FIFO 复位复位0 = 复位后复位后FIFO 指针位指针位01 = 重新使能接纳重新使能接纳FIFO 的操作的操作RX FIFO中断使能位中断使能位0 = 制止

17、基于制止基于RXFFIVL匹配的中断匹配的中断1 = 使能基于使能基于RXFFIVL匹配的中断匹配的中断RX FIFO中断标志位中断标志位 (read-only)0 = not occurred1 = occurredRX FIFO中断标志清零位中断标志清零位0 = no effect1 = clearRX FIFO溢出标志位溢出标志位 (read-only)0 = no overflow1 = overflowRX FIFO溢出标志清零位溢出标志清零位0 = no effect1 = clear0ABDCLR123456789101112131415CDCABDFFTXDLY这些位规定了从这些位规定了从FIFO发送缓冲奇到发送移位存放器之间发送缓冲奇到发送移位存放器之间每一次传送的延时每一次传送的延时 确定确定 SCI 波特率时钟周期的个数波特率时钟周期的个数( 0 to 255 )CDC 校准自动检测位校准自动检测位0 = 制止自动检测校准制止自动检测校准1 = 使能自动检测校准使能自动检测校准自动波特率检测自动波特率检测标志位标志位 (read-only)0 = not complete1 = complete自动波特率检测