DDR2 connection BF607

hi !

I'm not sure if we need to use series damping terminators as shown in the ADSP-BF609 EvalBoard.

We are very close to the DSP(BF607) - similar as shown in the eval board - and therefore I don't see the recommendation

to use Rs(series resistors). Also the eval board use 0Ohm resistor arrays ?????

So I know the topic but want to reduce the board size and the partlist.

Is this an option to eliminate the resistors??

And does the usage of the ODT-feature avoid this problem ???



  • 0
    •  Analog Employees 
    on Mar 24, 2015 8:43 AM over 5 years ago

    Hi Chris,

    I am not a board design expert, but as per my understanding, the best way to decide whether you would need the series termination resistors or not is to perform the simulations for the signal integrity and check how the signals look like. Yes, ODT may help you to reduce/avoid the need of these resistors, but in case the ODT options available aren't enough, you may need to still use the series resistors. As long as possible, it is safe to keep the provision for these resistors just like in the EZ-Kit. However, in case you have the size constraints, you may need to make a decision based on your simulation results.

    Additionally, we also have two programmable drive strength settings (full and half drive) which can do job similar to adding the series termination resistors. Having said this, again, I would insist that you do the board design simulations with different ODT/drive strength settings and then take a decision on whether you still need series termination resistors.



  • Hi !

    Thanks for reply - I know that it should be the best to simulate the signals, but currently we don't have

    the tools to do this. So I try to find a solution. Is there any known tool which is no to expensive.

    I searched to find any openSource tools but currently I don't find anything.

    kind regards