[hpsdr] Atlas bus lines C29 and C31

[Scott Cowling]

Thanks, Bill for your concise explanation.

I encourage everyone to look at the Atlas schematic here:

http://openhpsdr.org/support/Atlas/atlas_1_REVA_BW_schematic.pdf

You can see that on each connector page the pins that Bill indicated 
form a daisy-chain from slot to slot and are not bused as are A2 - 
A25 and C2 - C25.

Sure made it interesting when it was time to build the loop-back test 
fixture. :-)

73,
Scotty WA2DFI


At 11:44 PM 3/20/2011 -0500, Bill Tracey wrote:
>***** High Performance Software Defined Radio Discussion List *****
>
>A27, A29, A31, C27. C29, and C31 are not paralleled as the other 
>Atlas lines are - they're cross connected so you can get a chain 
>from slot to slot to slot.   A27 and A29 are used for the JTAG chain 
>and at the time Atlas was done it was thought to be a good idea to 
>have a few more setup that way.     You're not the first to get 
>caught by this one!
>
>Cheers,
>
>Bill (kd5tfd)
>
>
>At 05:56 PM 3/20/2011, Joe Martin K5SO wrote:
>>***** High Performance Software Defined Radio Discussion List *****
>>
>>
>>All,
>>
>>Relax.  As Joe K1RQG points out to me, from the Atlas documentation 
>>it seems that C29 and C31 have been made intentionally different 
>>from most bus lines, for some reason.
>>
>>However, this mean that the communications specification that we 
>>currently have for comm lines between Ozy/Magister/Metis and 
>>Mercury is invalid, as C29 and C31 fall in the middle of the 8-line 
>>comm spec that exists for that specification.
>>
>>In Metis v1.1 and Ozy 6.3 I avoided use of the C29 and C31 lines 
>>and used A6 and A4 instead for those two sets of firmware.
>>
>>It occurs to me that the two "missing" data lines (C29 and C31) of 
>>the 8-line comm spec could easily be the reason were earlier were 
>>plagued with strange audio "popping" phenomena.  Lately many of the 
>>apps run using only a single NWire communication between the boards 
>>so the "missing" lines weren't important, until you try to use one 
>>of them for the NWire comm, hihi.
>>
>>Sorry to put out a general alert but it sure looked like one was 
>>warranted to me at the time.
>>
>>73,  Joe K5SO
>
>_______________________________________________
>HPSDR Discussion List
>To post msg: hpsdr at openhpsdr.org
>Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
>HPSDR web page: http://openhpsdr.org
>Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/



 1300687255.0