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andrewlucas9
andrewlucas9
Associate II
May 9, 2013
Question

STM32 flash download demo issues with connecting

  • May 9, 2013
  • 2 replies
  • 998 views
Posted on May 09, 2013 at 16:53

Attached are two logic analyzer traces.  You can download the software to view them from here:

http://www.saleae.com/downloads

What you see is that when I use the flash loader demonstrator tool, the connection fails.  It fails for the following reason.  The bootloader is not correctly determining the baud-rate.  The bootloader is sending 0x7F at 115200 bps, but the bootloader configures itself as approximately 11000 bps.

When I use my own flash loader you can see that the bootloader correctly configures itself as 115200bps.

The particular processor I am targetting is the STM32F205ZC

From what I can tell the only difference is that for the ST-tool the TX line goes high only 600us before the 0x7f is sent.  In my case the TX line goes high long before the 0x7f is sent.

Is there a fix for this from ST?

I am using version 2.6.0 of the flash loader demonstrator from Nov 2012.

Note: in my traces the boot0 and reset lines are inverted polarity from the data sheet.

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    2 replies

    Tesla DeLorean
    Tesla DeLorean
    Guru
    May 9, 2013
    Posted on May 09, 2013 at 19:11

    Is there a fix for this from ST?

    It's in ROM, it is what it is.

    It tests for the auto-baud data pattern once after reset.

    Make sure you're using 8-bit Even parity. For an STM32 this would require 9-bit mode.

    Export your plots in PDF, JPG or PNG, something web friendly.
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    andrewlucas9
    andrewlucas9Author
    Associate II
    May 9, 2013
    Posted on May 09, 2013 at 19:38

    Here are pictures if that helps.

    I realize the bootloader is in ROM, but it is the same bootloader in both cases. The only difference that I can surmise that accounts for the different behavior is the way the host drives the TX line.

    ________________

    Attachments :

    Flash_Downloader_Tool_Failure_to_Connect.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0wC&d=%2Fa%2F0X0000000bfq%2FqdsB7FHvHvAVM8izMDjRanWpJWUrqKxZKcOcgBa_cKA&asPdf=false

    Personal_Downloader_Tool_Success_to_Connect.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0w7&d=%2Fa%2F0X0000000bfr%2FCQfbYATCdVBgFg04URaLj4zw5BQ.3W6qWcqrP5au2Dw&asPdf=false
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