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OV5642 camera PLL settings problem (on sabdresd board)

Question asked by Omar Pighi on Jan 25, 2013
Latest reply on May 16, 2016 by Raana

WE are using a module(made by us) with the ov5642 sensor (supported in the sabdr SD board bsp).

starting it with it's default values (initila_values table in the ov5642.c) it works fine with VGA resolution and 30 fps (PCLK is 48Mhz from 24Mhz mclk derived from the MX6Q).

But when we try to change capture mode to any other , the PLL seem to fail.

I mean the driver load a new register table where there are new pll register settings, and what we have is a very very very unstable PCLK with a wrong value (maybe 5- 10 Mhz) and of course fps is wrong , image is crappy.... etc etc etc...

WE made some test and the problem is in the tables (we tested almost all mode present in the driver).

We tried to reload always the initial_values table, and it works fine. We made this test to understand if the problem was in the operation to change mode or

in the table values then the problem is in the table value that set the pll in a bad status.

It could be the values or the sequence used to set the values .....

On the ov5642 data sheet i didn't find a lot about pll usage and precaution to change its values, i found just the register meanig (and not so clearley explined)...

So i don't know if there is any special sequence to change its settings...

 

Thanks

Omar

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