• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 98 subscribers
  • Views 484 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Is boundary-scan working, if the EMU1 pin of a TI ARM chip is held low?

Christoph Zimmermann
Prodigy 50 points
Other Parts Discussed in Thread: TMS320C28346, OMAP3515, OMAP-L138, AM3359, AM3357, OMAP3530

Our company is using a large range of DSPs from TI for our products. Now for a new product we are planing to use also an ARM processor from TI so there are questions coming up about programming and testing during manufacturing.

We would like to daisy-chain the JTAG interface of the ARM processor with an FPGA. We do this already successfully with the DSPs.

In the documentation for the DSPs (ex. TMS320c28346) there is noted that to use boundary-scan, the pin EMU1 has to be low (default is 1). In our production we have custom designed adapters to reflect this behavour during test and FPGA programming.

In the ARM documentation I haven't found any usable note if boundary-scan works if the EMU1 pin on a ARM is low. In fact, the datasheets and TRMs (OMAP3515, OMAP-L138, AM3359) are completely missing information about boundary-scan.

The documentation about the ICEPICK tap router lacks also such information (http://processors.wiki.ti.com/index.php/ICEPICK).

Is boundary-scan working, if the EMU1 pin of a TI ARM chip is held low?

  • 0
    TI__Guru**** 170625 points

    Hi Christoph,

    Please check these links for OMAP35x and boundary-scan:

    http://processors.wiki.ti.com/index.php/Boundary_Scan_on_OMAP35x

    http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/29620.aspx

    http://e2e.ti.com/support/dsp/omap_applications_processors/f/447/t/35977.aspx

    Regards,

    Pavel

  • 0 in reply to Pavel Botev
    Prodigy 50 points

    Hi Pavel

    Thanks for your fast reply.

    Pavel Botev said:

    Please check these links for OMAP35x and boundary-scan:

    http://processors.wiki.ti.com/index.php/Boundary_Scan_on_OMAP35x

    http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/29620.aspx

    I already read this two sources. The OMAP35x seems very special compared to other TI processors.

    Pavel Botev said:

    http://e2e.ti.com/support/dsp/omap_applications_processors/f/447/t/35977.aspx

    That is a well picked example, a long thread of questions and just a few answers. Does also not help.

    I posted this to the OMAP forum because they should be known better, and hopefully I get an answers.

    In our case we are desigining with the AM3357, I found the work "boundary-scan" in the features list but nowhere else (Datasheet, TRM).

    As it seems, all of this processors use the ICEPICK Tap router (also very sparely documented in the TRMs), so it would be helpfull for all ARM users to have an documentation about the boot modes of it.

  • 0 in reply to Christoph Zimmermann
    TI__Guru**** 170625 points

    Hi Christoph,

    Traditionally on C6x devices the EMU0 and EMU1 pins would be pulled high for normal operation for debugging, and would be pulled low for boundary scan mode, however for the OMAP3 it seems that one should have these pins pulled high at all times: EMU0=EMU1=1

    http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/30112.aspx

    http://elinux.org/OMAP3530_ICEPICK - here you will find a presentation describing the functionality of the ICEPick TAP Router.

    I hope this would be in help.

    Regards,

    Pavel

  • 0 in reply to Pavel Botev
    Prodigy 50 points

    Pavel Botev said:

    Traditionally on C6x devices the EMU0 and EMU1 pins would be pulled high for normal operation for debugging, and would be pulled low for boundary scan mode, however for the OMAP3 it seems that one should have these pins pulled high at all times: EMU0=EMU1=1

    [...]

    http://elinux.org/OMAP3530_ICEPICK - here you will find a presentation describing the functionality of the ICEPick TAP Router.

    Thanks for mentioning this link. This information is not comming from TI, can you confirm that the information they provide is correct?

    http://elinux.org/OMAP3530_ICEPICK said:
    EMU0 EMU1
    0    0    ICEPick + default TAP(s)
0    1    ICEPick Reserved
1    0    ICEPick Wait-in-reset
1    1    ICEPick Default condition

    NOTES: ICEPick is always in the scan chain

    The OMAP3xx has NO default TAP (ARM or ETB taps) which means that the configuration of EMU0-L/EMU1-L doesn't add ARM to scan chain.

    A table like that was what I was looking for in the datasheets or the TRMs.

    Still missing is the information about the "default TAP(s)" for a OMAP-138L and the AM3359 and in which modes boundary-scan is available (as it seems, it is available at least in mode 1 1 "Default condition").