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some question on the UART of th DM648

Hello:

  recently, I've tried to run the uart example(the program is supplied by LYRTECH, our evmDM648 bord bought from the LYRTECH) on the evmDM648  bords. However, when we load the .out file of the uart example to the dsp, there is no chars received by the PC, besides, we  use the Oscilloscope to measure the uart tx pin and found no changes during the program running(~3.3V on the pin). After discussion, we guess that there may be some problem on the software or hardware. Next, two methods to be used.  (1) we configure the UART to work on the loopback mode, and find that the receive register(RBR) can get the chars we have sent(the chars changes every sending), and the statement "GIO_read or GIO_submit" used to read returns the error "timeout"; (2) we run the "evmPost" programs to test the evmDM648 bord, when connectting the rx pin to the tx pin, the result of tesing show that the uart is good, and we can find the sending data on the tx pins.

and the pspdriver vision is pspdriver_1_10_00_09(supplied by LYRTECH or TI). And both interrupt and polled,both fifo enable and fifo unable, both loopback and not loopback we have tried(2*2*2=8 conditions), the problems is descripted above in each condition.

what causes this problem and how to solve that, I hope somebody can help me, thank you !

 Best regards!

M.Y. Wu

  • Hi maoyang wu,

    Please refer the PSP_Release_Notes.pdf placed in the top level docs folder of the pspdrivers package for details regarding UART and necessary settings required before using the UART example(sample application). In the release notes, under section - "Notes to user on sample application" mentions that -

    "Some peripherals like SPI and UART need the EVM configuration switch (SW2 and SW3) settings to be proper. Please refer to EVM documentation from the EVM manufacturer" 

    Hope you have taken care of  these steps before using the sample application.

    Also, Please refer the "Installation and Usage Procedure" section of the Userguide.

    Hope this helps..

    It looks like you have another similar post in - http://e2e.ti.com/support/embedded/bios/f/355/t/165512.aspx#603126

    You can simply reply to this post, and post your further queries. Lets continue our conversation in this post itself.. :)

    Thanks & regards,

    Raghavendra

  • Hi,Raghavendra:

    I'm very glad to receive your reply and thank you for your help. Have done as youe advice, the problem has been solved. Thank you!

    Best regards

    M. Y. Wu