How to use parallel interface of ADS62P42.

Hello,

Typically, the high speed ADC such as the ADS62p42 are used to interface with FPGAs or TI's GC digital up/down converter solution. I am not sure the proper setup and connection of the ADC to the C28346. I will move the forum to the C2000 forum for the team to comment.

-KH

for high speed data acquisition, like in ur case, more than 1Mbps then u need use XINTF with DMA channel. in ur case, if ur data rate is 25MSPS, c2000 is not designed for such high bandwidth signal. 300MHz/25MHz, each data would just have 1.2 cycles?  what r u gonna do with this ADC? image processing?

Well my only option is to use C28346..

Yu Cai said:

what r u gonna do with this ADC?

I want to detect coincidental impulses and send their amplitudes to a PC. 

Yu Cai said:

300MHz/25MHz, each data would just have 1.2 cycles? 

Why?

Janek Olszak said:

300MHz/25MHz, each data would just have 1.2 cycles? 

Why?

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That 1.2 looks like a typo.  It should be 12.  What Yu is trying to say is that you will have 12 cycles per sample to dothe processing required if you are running at 25MSPS.  This is going to limit your processing/maximum throughput. 

Note that CPU overheads such as interrupts can eat up cycles (an interrupt can take between 25 and 50 cycles without any user code) but using DMA will help, allowing you to process data block by block (reducing interrupt count).  This will leave you with less than 12 cycles per sample.  This will mean that you cant do much signal processing and it is likely that you will have to write some assembly code.

Overall, it is likely that your maximum throughput will be governed by processor speed rather than interface speed.

Tim

 

Tim King said:

This will leave you with less than 12 cycles per sample.

I think I'll fit, for this is not a real realtime device. The only realtime computation is detecting impulses ( checking if the amplitude is greater than the threshold) . After detection I've got more than 3us to process them. (input are signals from radiation detectors with dead time of about 4us ).

Tim King said:

Note that CPU overheads such as interrupts can eat up cycles (an interrupt can take between 25 and 50 cycles without any user code) but using DMA will help, allowing you to process data block by block (reducing interrupt count)

Instead of using DATA VALID signal from ADC as an interrupt can I connect it  to XREADY input? DMA would operate continuously and latched data would always be valid. 

This could significantly reduce the interrupt overhead.

thanks,

Janek