Hi, I'm having problems with SPI loobpack. The data transmitted by SPI are received correctly by SPI receiver. The interrupt for both receive and transmit are triggered correctly. However, the pin output was incorrect as I only saw one blip of SPI clock signal. Following is my code (TMS320F28035)
void enableSPIb() { SpibRegs.SPICCR.bit.SPISWRESET = 0; // reset SPI SpibRegs.SPICCR.all = 0x001F; // 16bit loopback, change to 0x000F on final SpibRegs.SPICTL.all = 0x0017; SpibRegs.SPISTS.all = 0x0000; SpibRegs.SPIBRR = 0x000F;//233; SpibRegs.SPIFFTX.all = 0xC022; SpibRegs.SPIFFRX.all = 0x0022; SpibRegs.SPIFFCT.all = 0x00; SpibRegs.SPIPRI.all = 0x0010; SpibRegs.SPICCR.bit.SPISWRESET = 1; // enable SPI SpibRegs.SPIFFTX.bit.TXFIFO = 1; SpibRegs.SPIFFRX.bit.RXFIFORESET = 1; } interrupt void spibTxFifoIsr() { int i = 0; int messageLength = 8; int16 pdx; while (SpibRegs.SPIFFTX.bit.TXFFST != 0) {} for (i = 0; i < 2 && SPICounter < messageLength; i++) { pdx = SPIChars[SPICounter++]; SpibRegs.SPITXBUF = pdx; } SpibRegs.SPIFFTX.bit.TXFFINTCLR = 1; PieCtrlRegs.PIEACK.all |= 0x20; } interrupt void spibRxFifoIsr() { int i; //for (i = 0; i < 2; i++) { receivedFromSPI0 = SpibRegs.SPIRXBUF; receivedFromSPI1 = SpibRegs.SPIRXBUF; //} SpibRegs.SPIFFRX.bit.RXFFOVFCLR = 1; SpibRegs.SPIFFRX.bit.RXFFINTCLR = 1; PieCtrlRegs.PIEACK.all |= 0x20; }
And this is the GPIO initialization:
// GPIO-12 - PIN FUNCTION = --Spare-- GpioCtrlRegs.GPAMUX1.bit.GPIO12 = 3; // 0=GPIO, 1=TZ1, 2=SCITX-A, 3=SPISIMO-B GpioCtrlRegs.GPADIR.bit.GPIO12 = 1; // 1=OUTput, 0=INput // GpioDataRegs.GPACLEAR.bit.GPIO12 = 1; // uncomment if --> Set Low initially GpioDataRegs.GPASET.bit.GPIO12 = 1; // uncomment if --> Set High initially GpioCtrlRegs.GPAPUD.bit.GPIO12 = 0; GpioCtrlRegs.GPAQSEL1.bit.GPIO12 = 3; //-------------------------------------------------------------------------------------- // GPIO-13 - PIN FUNCTION = --Spare-- GpioCtrlRegs.GPAMUX1.bit.GPIO13 = 3; // 0=GPIO, 1=TZ2, 2=Resv, 3=SPISOMI-B GpioCtrlRegs.GPADIR.bit.GPIO13 = 0; // 1=OUTput, 0=INput // GpioDataRegs.GPACLEAR.bit.GPIO13 = 1; // uncomment if --> Set Low initially GpioDataRegs.GPASET.bit.GPIO13 = 1; // uncomment if --> Set High initially GpioCtrlRegs.GPAPUD.bit.GPIO13 = 0; GpioCtrlRegs.GPAQSEL1.bit.GPIO13 = 3; //-------------------------------------------------------------------------------------- // GPIO-14 - PIN FUNCTION = --Spare-- GpioCtrlRegs.GPAMUX1.bit.GPIO14 = 3; // 0=GPIO, 1=TZ3, 2=LINTX-A, 3=SPICLK-B GpioCtrlRegs.GPADIR.bit.GPIO14 = 1; // 1=OUTput, 0=INput // GpioDataRegs.GPACLEAR.bit.GPIO14 = 1; // uncomment if --> Set Low initially GpioDataRegs.GPASET.bit.GPIO14 = 1; // uncomment if --> Set High initially GpioCtrlRegs.GPAPUD.bit.GPIO14 = 0; GpioCtrlRegs.GPAQSEL1.bit.GPIO14 = 3; //-------------------------------------------------------------------------------------- // GPIO-15 - PIN FUNCTION = --Spare-- GpioCtrlRegs.GPAMUX1.bit.GPIO15 = 3; // 0=GPIO, 1=TZ1, 2=LINRX-A, 3=SPISTE-B GpioCtrlRegs.GPADIR.bit.GPIO15 = 1; // 1=OUTput, 0=INput // GpioDataRegs.GPACLEAR.bit.GPIO15 = 1; // uncomment if --> Set Low initially GpioDataRegs.GPASET.bit.GPIO15 = 1; // uncomment if --> Set High initially GpioCtrlRegs.GPAPUD.bit.GPIO15 = 0; GpioCtrlRegs.GPAQSEL1.bit.GPIO15 = 3;
Any idea on how to fix this?
Thanks
