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DM8148 DSP Access to Serial and USB

DerekG
Intellectual 985 points

Hi

Based on the below diagram and the DSP/EDMA, it looks like the DSP has access to the Serial Ports and USB. But it is not entirely clear that this is the case.

Can you confirm whether or not  the DSP can access the serial ports and the USB through the EDMA MMU.

  • 0
    TI__Intellectual 1790 points

    Hi Derek,

    More information about the interconnect operation on the device is available in Chapter 5 of the datasheet. Table 5-1 (Page 171) indicates the connection via the L3 bus (for USB connectivity) and Table 5-2 (Page 172) indicates this for the L4 bus (for Serial connectivity). For these peripehals connections exsits between:

    USB - C674x SDMA, C674x CFG
    UART - DSP/EDMA MMU (DEMMU), C674x CFG

  • 0 in reply to Michael Brooks
    Intellectual 320 points

    Hi Derek,Michael,

    I take care of  the connection between device and c674x also.The datasheet said we can control the extern device by DSP/EDMA MMU (DEMMU).But i cann't found any source code or succed project about the DEMMU. Can you give me some examples which run in c674x ?It's very import for our design!

    Best Regards & Thanks !

    CheneyLiu

  • 0 in reply to cheney liu
    TI__Intellectual 1790 points

    Hi Cheney,

    I'm still looking for a code example for the DEMMU, but the best place to start is the System MMU chapter (chapter 1.4) of the TRM (http://www.ti.com/litv/pdf/sprugz8):

    The method for setting up the MMU can be found in section 1.4.4, "MMU Low-Level Programming Models". The fastest way to enable the MMU is to setup a static TLB (the process gets more complicate if you enable  table walking in the MMU), as described in Table 1-49, "MMU Writing TLB Entries Statically". Following this process will enable you to map the appropriate memory to contral external devices via the DSP.

    I'll provide an update if I can find a code example (I assume you want a high level Linux implementation), but the static implementation from the TRM will certainly work.