[hpsdr] Blackfin

[J.D. Bakker]

At 11:13 -0400 12-07-2007, Frank Brickle wrote:
>***** High Performance Software Defined Radio Discussion List *****
>
>Chris Albertson wrote:
>
>>  Think of it as putting a second PC inside the front end
>>  and then letting the two PCs (the one inside and the one
>>  one your desk) "talk" over a normal medium bandwidth
>>  connection, likely 100BaseT.
>
>Maybe the question is, then, why not simply make it a mini-ITX?

Noise and bandwidth.

With a DSP or other embedded processor it is often quite easy to 
position the clock noise such that it has the least impact (i.e.: 
RFI) on sensitive analog signals (driving the DSP's PLL off the 
converter master clock is an obvious first step). This is pretty much 
impossible on a mini-ITX board, even if you were lucky/persistent 
enough to get its schematics and data sheets for all components.

The Blackfin (and many other DSPs) have direct interfaces for high 
speed low latency data converters, which is harder to achieve with 
PC-standard interfaces such as USB or PCI.

Sure, any DSP or special-purpose processor can go obsolete and/or 
EOL, but the same goes for the FPGAs that are already on 
Janus/Ozy/Mercury.

JDB.
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