some query about VLYNQ

VLYNQ relies on 8b/10b block coding to minimize the number of serial pins and allows for in-band packet delineation and control.  For more information, refer to the VLYNQ User Guide for the platform you are working with.

VLYNQ being serial protocol it will have reduced numbers of pisn.. thats right ..

But how this 8b/10b coding bloack helps in reducing number of pins ?

VLIYNQ being serial protocol wil have reduced number of pins-- thats right..

But how 8b/10b coding help in reducing number of pins ?

As you probrably know, when you map 8-bit symbol (256 possible combinations) into 10-bit symbols (1024 possible combinations), you will have many of the potential 1024 combinations left over for other uses.  For instance you can use some of the 1024 combinations for control signals that would otherwise require other pins to implement.  In VLYNQ, some of these extra 10-bit codes are used for in-band packet delineation and control codes, which avoid the need to have extra pins for these features.  I hope this helps clear things up. 

hi..

I guess its clear now..

thanks..

by the way can you guide me, where can I find example code for VLYNQ interface ?

I am interfacing DM6467 with FPGA- xilinx-Virtex-4.  Initially I would be running VLYNQ interface using CCS and not in linux based system. So linux based drivers those are currently available-- I can not use them as it is.

I just need some start point to run VLYNQ interface using CCS.

The only ccs-based vlynq example I am aware of is a vlynq loopback test spectrum digital provides.  See the "DaVinci HD Test Code" section at the following link

http://support.spectrumdigital.com/boards/evmdm6467/revf/

hi

have you sucessfully used the VLYNQ code at spectrum provided at spectrum digital site i am using it with DM6446 and m having problem.

Regard's

Rohan Tabish

I have not tried the VLYNQ test in particular (I believe this may require some hardware mods to connect RX and TX pins), but based on other tests I have tried, I should mention that you should use the GEL files provided with the test suite to run the tests.  I have ran into situations where the tests did not run properly unless I used the GEL files which came with these tests.

The vlynq test example uses cpu to move data trough vlynq. Is there some edma example? The vlynq user guide says:"The VLYNQ module uses a 16-word deep FIFO to buffer the burst writes. Since the EDMA3 controller is much faster compared to the serial VLYNQ interface, a data back-up can occur. Therefore, configuring EDMA3 for optimal transfer size, etc. is essential." And how to configure the transfer size? When the transfer size is muchu larger than 16word,what happens?Could u explain in detail!