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Accessing UART2 via the Chip Support Library

Helge Rasmussen
Prodigy 40 points

Other Parts Discussed in Thread: TMS320C6748, OMAP-L138

Hi,

I am working on a 6748, and try to use the UART2 port by using the CSL.

The best example I have found is in ti\pspiom\cslr\evmOMAPL138\examples\uart\src\uart_example.c

Unfortunately this is only demoing loopback, not using the port for real, so my first question is: Is there a better example around?

 

To make the code work for UART2, I assume I have to enable the port in the PINMUX, so I added the following lines to the start of device_init() in uart_example.c:

    sysRegs->KICK0R = 0x83e70b13;
    sysRegs->KICK1R = 0x95a4f1e0; /* To enable modifying pinmux */

    sysRegs->PINMUX0 = 0x44440000; /* To enable UART0, UART1 and UART2 pins */
    sysRegs->PINMUX3 = 0x22220000;
    sysRegs->PINMUX4 = 0x22220000;
                       
    sysRegs->KICK0R = 0x00000000; /* To lock pinmux again */
    sysRegs->KICK1R = 0x00000000;

After this, I tried to write out all PINMUX registers, and they are unchanged... What am I doing wrong?

Later in the code I removed setting the loopback flag, and I changed it to use UART2, and but the code does not work. I assume that its because the pinmux hasn't been set up correct.y.

Helge

  • 0
    TI__Guru 62975 points

    Helge,

    I would recommend that you not lock the KICK registers.  This usually leads to headaches where another function/process unexpectedly locks out register access.  The KICK lock-out function was disabled on Silicon Revision 2.

    You should be able to access the PINMUX registers after the KICK registers have been unlocked.  As a sanity check, can you try to modify the PINMUX registers through a CCS memory window?

    -Tommy

  • 0
    TI__Mastermind 24340 points

    Helge Rasmussen said:

    The best example I have found is in ti\pspiom\cslr\evmOMAPL138\examples\uart\src\uart_example.c

    Unfortunately this is only demoing loopback, not using the port for real, so my first question is: Is there a better example around?

    If you prefer to use PSP instead of CSL, please see examples at:

    C:\Program Files\Texas Instruments\pspdrivers_01_xx_xx\packages\ti\pspiom\examples\evm6748\uart

     There is also the BSL example:

    ...\1014014A_TMS320C6748_GEL_BSL_Files\evmc6748_v1\tests\experimenter\uart

    OR

    ...\1014013A_OMAP-L138_GEL_BSL_Files\evmomapl138_v1\tests\experimenter\uart

    Go to LogicPD's web site.

    Click on the Kit Contents tab, at the bottom of the page click at: TMS320C6748 SOM-M1 GEL, CCS Setup, & BSL Files - you will need to create an account in their website if you do not have one already and download the files.

     

  • 0 in reply to Mariana
    Prodigy 40 points

    Thanks for the references, I will have a look at them.

     

    I figured out the problem with the pinmux::

    As part of boot of my code I switched to User Mode, and the pinmux is only accessible in Supervisor Mode. When I moved the code up to before the switch, everything worked.

    I will also stop locking the pinmux.