4DSP Support Forum

Products => FMC Products => FMC112, FMC116 => Topic started by: chetan.patil on February 25, 2015, 06:48 AM

Title: ML605_FMC112 Firmware: ADC Digital output code format
Post by: chetan.patil on February 25, 2015, 06:48 AM: Dear Sir,

Waiting for your reply.
Pls. do it ASAP.

Dear Sir,

As per LTC2175 ADC datasheet, two types of digital output codes for given analog input are possible, which are as given below

1. Offset binary (default)
2. 2's complement form (can be selected using serial programming mode control register A1)

I want to know, which type of digital output code is used in ML605_FMC112 reference firmware design.
ASAP.

Thanks & regards,
Chetan Patil.
Title: Re: ML605_FMC112 Firmware: ADC Digital output code format
Post by: rzandvliet on February 26, 2015, 10:41 AM: Dear sir,

The digital output of the LTC2175 ADCs are set to 2’s complement.

Please let me know if you have further questions.

Best regards,
Rémon Zandvliet
Title: Re: ML605_FMC112 Firmware: ADC Digital output code format
Post by: chetan.patil on February 27, 2015, 04:31 AM: Dear Sir,

Thanks for your reply.

Now our understanding is, ADC samples are using 2's complement code of 14 bit length which are left justified to 16 bit ("14 bit sample value" concatenated with "00") in 4DSP fmc112 reference firmware is it correct ? Pls. confirm.

Our requirement is to find out maximum sample value out of the in-coming ADC samples so we are doing signed value comparison of incoming sample values. Pls. confirm whether this logic is correct or not ?

Thanks & regards,
Chetan Patil.
Title: Re: ML605_FMC112 Firmware: ADC Digital output code format
Post by: rzandvliet on March 02, 2015, 10:14 AM: Dear Sir,

Yes, the ADC samples are 14 bit 2’s complement values and are left adjusted. Comparing the value of the incoming ADC samples with the highest value that has already been found is a method to determine the highest sample value.

Best regards,
Remon Zandvliet
Title: Re: ML605_FMC112 Firmware: ADC Digital output code format
Post by: chetan.patil on March 03, 2015, 02:14 AM: Dear Sir,

Thanks for your reply.

Regards,
Chetan Patil.
Title: Re: ML605_FMC112 Firmware: ADC Digital output code format
Post by: arnaudNL on March 03, 2015, 07:59 AM: This topic is being closed because the issue is considered as resolved by 4DSP. Feel free to create a new topic for any further inquiries.