AM2434: Sinus Cosing resolver with AM243 ADC

Hello Jan,

I have assigned this thread to an Hw expert to provide inputs on this requirement, and I am also notified in this thread. If there are any software related queries I will provide a reply.

Regards,

Anil.

Hello Jan,

Please refer additional input i added based on my discussion with the device expert:

The ADC implemented in AM243x is a single channel SAR ADC with a multi-input analog multiplexer inserted on the input path.  Therefore, it is not possible for the ADC to sample two inputs simultaneously.

Regards,

Sreenivasa

Hello Kallikuppa, 

yes this has been already clear to the customer. And if we understood correctly also an external ADC like ADS9234R does not work on the QSPI interface (maybe you can confirm that finally). So the only option would be either  ADS9234R via PRU (this is not possible here because the PRU will be in use) or the decision that the customer made to use an ADS7253 or ADS7251.

Thank you 

Jan 

Hello Jan,

Here is the list of ADCs that have been interfaced,

Jan Bock said:

And if we understood correctly also an external ADC like ADS9234R does not work on the QSPI interface (maybe you can confirm that finally). So the only option would be either  ADS9234R via PRU (this is not possible here because the PRU will be in use)

QSPI i am not sure. PRU - understand.

Jan Bock said:

ADS7253 or ADS7251

refer section Terminal Descriptions of ADC data sheet. Any thoughts how customer plans to interface to Am243x?

Regards,

Sreenivasa

Hello Kallikuppa, 

Kallikuppa Sreenivasa said:

QSPI i am not sure

The documentation of the  AM243 says that QSPI is only for memory interface. ADS9234R has a dual SDO line, so there for normal SPI does not work. 

Kallikuppa Sreenivasa said:

refer section Terminal Descriptions of ADC data sheet. Any thoughts how customer plans to interface to Am243x?

For me it looks like through standard spi interface. Do you have any concerns here?

Thanks 

Jan

Hello Jan,

Thank you.

Jan Bock said:

Kallikuppa Sreenivasa said:

refer section Terminal Descriptions of ADC data sheet. Any thoughts how customer plans to interface to Am243x?

For me it looks like through standard spi interface. Do you have any concerns here?

As i understand, these ADCs also seem to have dual SDO output.

Regards,

Sreenivasa

Hello Kallikuppa, 

Kallikuppa Sreenivasa said:

As i understand, these ADCs also seem to have dual SDO output.

The ADS7253 has a Single-SDO mode:

whereas ADS9234R has not such a mode. 

Regards

Jan

Hello Jan,

Thank you for the inputs.

Regards,

Sreenivasa

Hello Kallikuppa, 

can you also clarify the contraints of the QSPI interface and why it is just declared as an memory interface?

Thanks 

Jan

Hello Jan,

Thank you.

TIs current implementations and software enablement has been around the OSPI/QSPI memory.

Regards,

Sreenivasa

Kallikuppa Sreenivasa said:

TIs current implementations and software enablement has been around the OSPI/QSPI memory.

So this means that it is a software and not a hardware constraint, correct? 

Hello Jan,

Thank you.

Jan Bock said:

TIs current implementations and software enablement has been around the OSPI/QSPI memory.

So this means that it is a software and not a hardware constraint, correct? 

I do not have a way to confirm the query.

This may require a detailed analysis.

Regards,

Sreenivasa