Re: [time-nuts] BeagleBone Black DDMTD update

2014-10-30 Thread Iain Young
Hi Simon, On 29/10/14 20:15, Simon Marsh wrote: This is a fairly long post, at the top is a bit of description of of changes since my last posts and then around the middle is some description of the data thats attached. The data raises a few questions, and I'll put those in a separate post.

Re: [time-nuts] BeagleBone Black DDMTD update

2014-10-30 Thread Simon Marsh
On 30/10/2014 07:12, Iain Young wrote: Hi Simon, On 29/10/14 20:15, Simon Marsh wrote: This is a fairly long post, at the top is a bit of description of of changes since my last posts and then around the middle is some description of the data thats attached. The data raises a few questions,

[time-nuts] BeagleBone Black DDMTD Update

2014-10-29 Thread Simon Marsh
original post had a lot of attachments, these have been uploaded here for viewing: https://drive.google.com/folderview?id=0BzvFGRfj4aFkMFBtNWFSZVBKWkkusp=sharing --- This is a fairly long post, at the top is a bit of description of of changes since my last posts and then around the middle is

Re: [time-nuts] BeagleBone Black DDMTD update

2014-10-29 Thread Bob Camp
Hi It is not at all unusual for signals to be re-clocked when going into a micro. Often the documentation on this process is somewhere between vague and non-exsistant. Bob On Oct 29, 2014, at 4:15 PM, Simon Marsh subscripti...@burble.com wrote: This is a fairly long post, at the top is a

Re: [time-nuts] BeagleBone Black DDMTD update

2014-10-29 Thread Simon Marsh
On 29/10/2014 22:22, Bob Camp wrote: Hi It is not at all unusual for signals to be re-clocked when going into a micro. Often the documentation on this process is somewhere between vague and non-exsistant. Bob Yes, luckily the Sitra TRM has a nice clear diagram for the mechanism I use and

Re: [time-nuts] BeagleBone Black DDMTD update

2014-10-29 Thread Bob Camp
Hi In the case of a 1 ps aperture on the flip flop, and a 100 fs delta between samples, there are two simple things that might happen: 1) You get random garbage for 10 counts. 2) The flip flop “hangs up” for 10 counts. To know which one you are going to get, you would need a pretty good

Re: [time-nuts] BeagleBone Black DDMTD update

2014-10-29 Thread Hal Murray
kb...@n1k.org said: It is not at all unusual for signals to be re-clocked when going into a micro. Often the documentation on this process is somewhere between vague and non-exsistant. Reclocking is almost required if you want to avoid metastability issues. There is often some