Other Parts Discussed in Thread: C2000WARE
Tool/software: Code Composer Studio
1. The SCI GPIO pin configuration in the C code (/sci_echoback_cpu01/Example_2837xDSci_Echoback.c) is wrong.
The code in the block comment is the original, the code below is corrected one which is working in the expected way.
See pp. 960 of 'SPRUHM8I–December 2013–Revised September 2019' for the reason why the original code is wrong.
/*
GPIO_SetupPinMux(28, GPIO_MUX_CPU1, 1);
GPIO_SetupPinOptions(28, GPIO_INPUT, GPIO_PUSHPULL);
GPIO_SetupPinMux(29, GPIO_MUX_CPU1, 1);
GPIO_SetupPinOptions(29, GPIO_OUTPUT, GPIO_ASYNC);
*/
GPIO_SetupPinMux(43, GPIO_MUX_CPU1, 15);
GPIO_SetupPinOptions(43, GPIO_INPUT, GPIO_PUSHPULL);
GPIO_SetupPinMux(42, GPIO_MUX_CPU1, 15);
GPIO_SetupPinOptions(42, GPIO_OUTPUT, GPIO_ASYNC);
2. The baud rate of serial terminal (e.g., Putty) must be set to 4800, not 9600.
It is due to the PLL setup code of the example. Here is the code from 'F2837xD_SysCtrl.c'
#ifdef _LAUNCHXL_F28379D
InitSysPll(XTAL_OSC,IMULT_40,FMULT_0,PLLCLK_BY_2);
#else
InitSysPll(XTAL_OSC, IMULT_20, FMULT_0, PLLCLK_BY_2);
#endif // _LAUNCHXL_F28379D
Unless the '_LAUNCHXL_F28379D' is defined in the CCS project, the chip on the kit, 28379D, would run 100 MHz, not 200 MHz.
Consequently, the SCI parameter setting in the example would make the speed 4800 bps, not 9600 bps.
Once all the changes are correctly made, here is what you would be able to see:
The FTDI Serial port was detected as COM4, when I tested the code.
