• Resolved

TMS320C5517: Disable UART and SPI while UHPI works

Part Number: TMS320C5517


I am looking at this DSP for a new design. I checked the EVM manual by Spectrum Digital.

On the C5517 EVM, the UHPI bus is used in order to download software from the MSP430 to the C5517.

On the literature of that EVM they write:

 HPI_ON = ON => HPI mode disabled
        HPI control and data lines not connected
        SDRAM CS enabled
        SPI(Flash)/I2S2/SPI(LCD) MUX (U23 & U29) enabled
        UART (U21) and Expansion SPI (U10) lines enabled

    HPI_ON = OFF => HPI mode enabled
        HPI control and data lines ar enabled
        SDRAM OE is disabled
        SPI Flash/I2S2/SPI LCD MUX disabled
        UART plus additional lines (U21 and U10) disabled


I wonder why do they disable the UART and the SPI and the SDRAM when the HPI is off?
On my project, I need 2 SPI's + 1 UART + HPI interface (connected to external FPGA) which works simultaneously.
The HPI would download parallel data from Xilinx FPGA using DMA, One SPI will control a display and another SPI will control the FPGA + UART sending and receiving commands from an external device.
Is it possible to implement that architecture using this DSP?
If I will disable the MSP430 part of the EVM, would I be able to use all of those inmterfaces simultaneously?
  • Hi,

    I've notified the sw team. They will post their feedback directly here.

    Best Regards,


     Please make sure you read the forum guidelines first.

  • Aronii,

    Fundamentally, the C5517 chip has several interfaces muxed among themselves. For example, signal P12 is muxed between UHPI and SPI.

    So, I would suggest taking a closer look at the datasheet to see if the interfaces that you desire for your application are present. Also, you mentioned that you need 2 SPI interfaces. The C5517 has only 1 SPI.


  • In reply to Lalindra Jayatilleke:

    Thanks, Lali,

    I have already noticed that and because of that I moved to the C6748 where al of those interfaces present all the time without any multiplexing.