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Cyclone MAX BDM Shift Frequency
Gregor A. Jan 30, 2017 at 07:48 AM (07:48 hours)
Staff: Takao Y.

  • Hello, 
    for the Cyclone MAX, Kinetis MKV10Z32 microcontroller, the lowest BDM shift frequency I can select in Image Creation Utility (v5.77.10.00) is 746 KHz.
    Is there any possibility to use even lower frequency?

    We found out that when connection between the programmer and circuit is too long, lowering the frequency helped. But in some cases, even 746KHz seems to be too high.


  • Greetings,

    Your cable must be a kilometer long! At such a lower frequency, it will take forever to flash program!

    When you add length to the cable, you are introducing noise. So by lowering the frequency this reduces the noise but never gets rid of it completely. What you should do is shield your cable. Just as a test, try wrapping tin foil around the cable and you will see that communication will improve. Then you can start using faster communication speed and complete your programming in a shorter time. You can then play around with even longer cables if you want as long as you shield the cable properly.

    Tin foil should only be a temporary solution since it can accidentally short any exposed pins and metal surfaces. If you want, you could repurpose a long USB or Ethernet cable by clipping off the heads of each side and using some of the wires inside. The shielding already on these cables are perfectly made for fast and reliable communication.

    Takao Yamada

    • Actually we had problem with less than 50cm flat cable between cyclone Max and the pcb with the microcontroller, where we had to use the lowest speed. We are programming in circuit.
      We also wanted to put a relay in between the programmer and the circuit (for programmer protection during testing of the pcb) and anything longer than 10 cm + signal relay, we get error #7 from the programmer. Even when we used shielded cable.

  • Greetings,

    You should do an analysis of the signals, using an oscilloscope, going from the cyclone to the relay. And then another analysis from the relay to the target. See where the problem occurs. You are looking for where the noise is occurring. If you see no noise, then the next thing to check is delay in rise times. If the problem is after the relay, then that is outside of the control of the cyclone to prevent this problem. You will need to implement a better relay with added capacitors to GND to reduce noise or pull-ups to help with rise times.

    Takao Yamada

  • Thank you for your answer. 
    If we find out something useful for others, I will post it here.

    Best regards,

  • If it is any use to others: we have solved the problem by putting a 680pF ceramic capacitor between CLK and GND lines on the module side.

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