ADS131M08: Can you let me know which address I can get the sampled data.

Bryan-san,

Thank you for the answer.

I understand that, after the DRDY to transition from high to low ADS131M08 output sampled data

while the SPI host is sending any 10 wards.

However, I still have one question.

Pease allow me asking one more question.

If the host send, say NULL command,  ADS131M08 may output status instead of sampled data.

How ADS131M08 switch the status and sampled data?

Mita

Hi Mita,

Bryan is travelling. Let me support you for your question.

Below is the timing of a typical communication frame between ADS131M08 and a microcontroller. The frame starts when the /CS signal becomes low and ends when the /CS is changed from low to high. The /CS signal is sent and controlled by the microcontroller.

If a command is sent to the ADC on DIN, the ADC will respond the command on the first word in the next (2nd) frame according to the table 8-11 in the datasheet. The rest of words in the 2nd frame include the conversion data of all channels and the CRC word.

When you are sending NULL (no operation) command to the ADC, the response on the first word in the 2nd frame will be the data of STATUS register. See the table 8-11 in ADS131M08 datasheet.

BR,

Dale

Dale-san,

Thank you for your reply.

I understand that the SPI frame includes most of case ten wards, and words includes
Command and its parameters.
The response of the Command comes out from DOUT on the next frame.

ADS131 outputs the Commad response. Meanwhile it also outputs sampled data as well.

My question is how does ADS131 switchs Command response and Sampled data.

In other words, what procedure can I follow to read out the sampled data?

For example, while /READY is low, will the sampled data be output from DOUT no matter what is input to DIN?

If so, will the data be output without waiting for the next SPI frame?

Mita

Hi Mita,

I have explained but it seems like you were still confused. There is no procedure in order to read the converted data (or sampled data).

The ADC's response depends the command you send to the ADC. If you are sending NOP (all '0's) commands, the conversion data of all 8 channels will be seen from the 2nd word to 9th word. 

-Dale

Dale-san,

Thank you for your answer.

So the sample data is output following the command response.

Let me confirm my understanding just to be sure.

Here is an example.

First, send a NULL command followed by 10 words of data.

Next, send some other command, for example, another NULL command followed by 10 words of data.

When you send the second NULL command, DOUT will output one word of response to the first NULL command,

followed by 8 words of sample data, correct?

Mita

Dale-san,

Thank you for your asnwer.

I got it.

Mita