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TMS320F28335: External SRAM and using XINTF on F28335 USB Docking Station

Part Number: TMS320F28335
Other Parts Discussed in Thread: TMDSCNCD28335

Hi,

how to add External SRAM on F28335 USB Docking Station (TMS320F28335)?

in this post, I understand both F28335 and SRAM are on the same board. When looking at the docking station, some of the GPIOs are not available on J4 - J7 connectors. The idea is to add external memory to the existing docking station.

In TMS320F2833x  document there is mentioning of external memory interface (XINTF), and pins GPIO14, GPIO15, GPIO34 have XINTF mentioned in their description.

In post is says "F28335 has an XINTF peripheral that is designed to interface with standard asynchronous SRAMs" and that adding the memory is "relatively seamlessly".

Several questions:

  • Are only those three GPIOs (14, 15 and 34) XINTF interface on Docking station with External SRAM?
  • In the example from the first post, there are many signals exchanged... Is there a scheme available somewhere and connection diagram for XINTF connection?
  • If I want to add external memory, what type and model to use. E.g. IS61WV51216BLL-10TLI has several Address Inputs and Data Inputs/Outputs pins and on F28335 are only three XINTF. Does this mean some other memory is needed?
  • When eventually I add the memory, is it automatically recognised or some work is needed? I saw some posts mentioning some Zone 6, Zone 7 configuration/change. I use MATLAB Simulink for coding. The setting possibilities are less compared with Code Composer Studio.

Thank you in advance.

  • mike buba said:
    how to add External SRAM on F28335 USB Docking Station (TMS320F28335)?

    Can you clarify what you mean by F28335 USB Docking Station?  If you are referring to orderable hardware, please include the part number or product name.

    The TMDSCNCD28335 controlCARD + docking station is not designed to directly support XINTF memories.  There is an eZdspF28335 board that does include an on-board SRAM.

    mike buba said:
    in this post, I understand both F28335 and SRAM are on the same board. When looking at the docking station, some of the GPIOs are not available on J4 - J7 connectors. The idea is to add external memory to the existing docking station.

    From what I understand, this user was using a custom-built board.

    mike buba said:
    In TMS320F2833x  document there is mentioning of external memory interface (XINTF), and pins GPIO14, GPIO15, GPIO34 have XINTF mentioned in their description.

    In post is says "F28335 has an XINTF peripheral that is designed to interface with standard asynchronous SRAMs" and that adding the memory is "relatively seamlessly".

    Yes, the XINTF is compatible with the industry standard protocol for interfacing with asynchronous SRAMs. This parallel interface uses many XINTF pins -- typically 20+ signals depending on the specific components. These memories are typically soldered onto the board for proper signal integrity. You can find high-level descriptions and waveform diagrams in the datasheet that you have linked, and further details in the TRM.

    mike buba said:
    Are only those three GPIOs (14, 15 and 34) XINTF interface on Docking station with External SRAM?

    The XINTF signals needed depend on the required data bus and address bus sizes. Please refer to the XINTF documentation to see which signals you require and whether they are available.

    mike buba said:
    In the example from the first post, there are many signals exchanged... Is there a scheme available somewhere and connection diagram for XINTF connection?

    This can be found in the TRM and the eZdspF28335 schematic.

    mike buba said:
    If I want to add external memory, what type and model to use. E.g. IS61WV51216BLL-10TLI has several Address Inputs and Data Inputs/Outputs pins and on F28335 are only three XINTF. Does this mean some other memory is needed?

    Please see the XINTF documentation.

    mike buba said:
    When eventually I add the memory, is it automatically recognised or some work is needed? I saw some posts mentioning some Zone 6, Zone 7 configuration/change. I use MATLAB Simulink for coding. The setting possibilities are less compared with Code Composer Studio.

    The XINTF needs to be configured through software to match the characteristics of your selected memory.

  • Hi tlee,

    thank you very much for the reply.

    I am also looking into creating a custom-build design for strictly academic and research purposes, but using some of the existing TI solutions, e.g. TMS320F28335 controlCARD and standard 100-Pin DIMM Interface. Something similar to this.

    tlee said:
    The TMDSCNCD28335 controlCARD + docking station is not designed to directly support XINTF memories

    Before doing any work I wanted to know if the TMS320F28335 controlCARD can use external SRAM. If I understood the reply correctly, this is not possible with TMS320F28335 controlCARD.

  • Mike,

    Right, the sensing and control signals were prioritized for the 100-pin connector, which did not leave room for a usable XINTF interface.

    -Tommy