VADC on VF6xx

[antonioboi]

Hello,
I'm trying to use the module VADC of Vybrid intending to capture some video PAL frames.

Here are the test conditions:
- I used the Vybrid Reference Manual Rev. 5, 07/2013 to configure all the registers
- Toradex Module VF61 with a MVF61NS151CMK50 chip
- 4 Input VADC discoupled with 47nF e 75ohm to ground signal
- A standard PAL signal on each input channel originated from a SONY videocamera

Modules configuration:

- PLL6 configured to 1064 MHz according to the 9-3 RM table
- PLL6 divided by 2 through the CCM_CACRR[PLL6_DIV_CLOCK] register
- PLL6 configured as a source of the VADC through the CCM_CSCMR1[VADC_CLK_SEL]register
- Clock of the VADC divided by 4 through the CCM_CSCDR1[VADC_DIV] register to obtain 133MHz
- Chosen VCAFE_VIN_0 through the AFE_INPFLT[mux_enlf] register
- Set pull-down VCAFE_VIN_1, VCAFE_VIN_2, VCAFE_VIN_3 through the AFE_OFFDRV[input_pulldown_en] register
- Enabled the clock to VADC through the CCM_CSCDR1[VADC_EN] register
- Introduced a 500ms delay

Reading the  VDEC_VIDMOD[PAL detected] register I always obtain a 0 value: unrecognized PAL .
Furthermore I read the VDEC_VIDMOD[m625] register always active, with or without input signal.

So, why is the VDEC_VIDMOD[PAL detected] register always null, nevertheless I connected a signal?
Is it necessary to configure some other register (AFE or VDEC) so that the VADC system could recognize the PAL standard?

Greetings
Antonio Boi

[naoumgitnik · Accepted solution]

Dear Antonio,

Please, take a look at the attached simplified test code pieces - most likely they contain all the settings you are looking for.

I am not a SW person, but below is a comment of how to use the attached code (again, not sure how relevant it i but still...):

“I placed your code into my project, but it could not build. However, I removed Boot directly and changed build option to "Debug". Then I could build without errors.

I will download this project and run it.”

Regards, Naoum Gitnik.

[antonioboi]

Thanks a lot Naoum,

I will try to use the code that you shared as a starting point to test the module VADC.

Regards, Antonio Boi

[naoumgitnik]

Dear timesyssupport,

May you refer Antonio to the code used on the Vybrid Automotive board - the one that also has 4 video inputs, please?

Sincerely, Naoum Gitnik.

[timesyssupport]

Hello,

Unfortunately, we do not have code for the Vybrid Automotive or the Toradex board for a VADC driver in Linux. I also checked MQX, and found related code at mqx/source/io/lwadc/, but I am not sure if this is what you are looking for.

Thanks,

Timesys Support