Hello,
I am having trouble getting the sci_echoback project working with my TMS320F28023DA. I went through all the header files and set the appropriate values.
#define DSP28_DIVSEL 2 // Enable /2 for SYSCLKOUT
#define DSP28_PLLCR 10 // Uncomment for 50 Mhz devices [50 Mhz = (10MHz * 10)/2]
#define CPU_RATE 20.000L // for a 50MHz CPU clock speed (SYSCLKOUT)
The SCI is initialized with the scia_fifo_init() and scia_echoback_init() functions which are shown below.
// Initalize the SCI FIFO
void scia_fifo_init()
{
SciaRegs.SCIFFTX.all=0xE040;
SciaRegs.SCIFFRX.all=0x2044;
SciaRegs.SCIFFCT.all=0x0000;
}
// Test 1,SCIA DLB, 8-bit word, baud rate 0x000F, default, 1 STOP bit, no parity
void scia_echoback_init()
{
// Note: Clocks were turned on to the SCIA peripheral
// in the InitSysCtrl() function
SciaRegs.SCICCR.all =0x0007; // 1 stop bit, No loopback
// No parity,8 char bits,
// async mode, idle-line protocol
SciaRegs.SCICTL1.all =0x0003; // enable TX, RX, internal SCICLK,
// Disable RX ERR, SLEEP, TXWAKE
SciaRegs.SCICTL2.all =0x0003;
SciaRegs.SCICTL2.bit.TXINTENA =1;
SciaRegs.SCICTL2.bit.RXBKINTENA =1;
// SCI BRR = LSPCLK/(SCI BAUDx8) - 1
#if (CPU_FRQ_60MHZ)
SciaRegs.SCIHBAUD =0x0000; // 9600 baud @LSPCLK = 15MHz (60 MHz SYSCLK).
SciaRegs.SCILBAUD =0x00C2;
#elif (CPU_FRQ_50MHZ)
SciaRegs.SCIHBAUD =0x0000; // 9600 baud @LSPCLK = 12.5 MHz (50 MHz SYSCLK)
SciaRegs.SCILBAUD =0x00A1;
#elif (CPU_FRQ_40MHZ)
SciaRegs.SCIHBAUD =0x0000; // 9600 baud @LSPCLK = 10MHz (40 MHz SYSCLK).
SciaRegs.SCILBAUD =0x0081;
#endif
SciaRegs.SCICTL1.all =0x0023; // Relinquish SCI from Reset
}
If I have setup everything correctly and calculated the baud constants correctly, this should be setup to communicate at 9600 baud. I tried calculating several other baud rates, but none of them worked. I am using the Hyperterminal config file provided with the example.
One thing I noted that was odd is that the datasheet lists this processor as 50 MHz, but when I look at the values in the F28xx On-Chip Flash Programmer it shows up as 40 MHz. Am I missing something here?
Any help with this problem will be greatly appreciated.
Thanks,
-Russell Morin
