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TMS320F28335: How to program a board from a distance of 100m from PC

Part Number: TMS320F28335

HI,

i need to debug/program the microcontroller which will be at a 100m from the PC. I thought of Ethernet programmer but, in that case i need to place a Emulator in my unit. Is there any option to extend the JTAG cable for a distance of 100m.

thanks and regards,

Arun Gopalakrishnan

  • JTAG cable must be short or capacitance kills the high frequency of the clock and data.

    Usually not more than a few inches, 1-2 feet maximum.  Depends on the clock speed and JTAG wiggler.

    If you must debug remotely, will need a local WIFI connected PC with the JTAG to your board  and control that PC remotely from another PC using any one of many virtual dersktop apps that are available.

  • Agree with Mark, the physical run of wires from the emulator probe to the device is what needs to be kept short as possible with a max of what he mentioned(in my experience anything more than a few inches becomes tricky to prevent noise coupling).

    With that said there could be a longer run for the connection from the debug probe to the PC, i.e. the USB cable.  However, a quick search on this reveals that for USB 2.x the max length allowed is 5m/16ft.

    I think what Mark suggested as the final soln is what is going to be the most dependable, i.e. a local PC with a short JTAG connection at the target, and remote into this with your local terminal.

    Best,

    Matthew

  • Thanks Mark...

    But the PCB is in remote location(100m) and i cannot place and connect emulator in the moudule. The PCB is in an enclosure which is not accessible easily.  Wifi cannot be used. The PCB is used for an telemetry application and only serial communication is available through cable.

    Can i use any SERDES in JTAG cable, anyone tried?

    Can i program the flash from another DSC?

    Thanks,

    Arun Gopalakrishnan

  • Hi Arun,

    I know of no way to run JTAG from 100m .

    You will need to build in some debugging capability on your serial link.  Ability to remotely request values of variables or events is usually sufficient but sometimes tedious.

    If you want to single step and set breakpoints and such, from 100m, there is no easy way.

    Best you could do is bring the remote unit to your desk and pretend it is 100m away.  Then you can debug from your PC directly.

    As far as remote Flashing, you would need to write your own apps for PC and target device.  This is done often, I havwe done this many times, but it is a lot of work.

    Mark

  • Hi Mark,

    There is an option for serial flash programming available in c2000 Controllers.

    Does it work in TMS320f28335 DSC?

    Given below is the signal flow path,

    PC<---> serial to 485 <----- 100m -------> 485 to Serial <--> DSC flash

    Regards,

    Arun Gopalakrishnan

  • Arun,

    Yes, serial flash programming is possible on the F2833x device.  We have two documents that will be useful for getting started:

    1)Serial programming guide, this is general C2000 document but talks about implementing a kernel (with examples) for different boot modes:http://www.ti.com/lit/sprabv4 

    2)F28335 Boot ROM User Guide: This is specific for this device, but goes through all the support boot modes, pins etc: http://www.ti.com/lit/spru963 

    The only thing left to consider is the signal integrity of the 100m run, which would be a function of the 485 transceivers and their datasheets.

    Best,

    Matthew

    All techinal documents for this device can be found here: http://www.ti.com/product/TMS320F28335/technicaldocuments

  • hi.

    thanks for the help...

    i am going for serial flash programming...

    Arun