AMC7812 ADC Continuous mode not working (SPI)

Roxana Ponce

Other Parts Discussed in Thread: AMC7812, AMC7812EVM-PDK

[Problem:
We are using the AMC7812EVM Rev2, we are trying to use the continuous mode of ADC and it is not working, we need to retrigger in order to read new values using the SPI interface]

[Steps Needed to Recreate Problem:

6B7FFe    ;== ADC, DACs and reference on

4C3400    ;== AMC Config Reg0 Continuous mode and internal reference

                           ;== enable

0A0000    ;== Temperature disable

506DFF     ;== Single ended channels configuration

4C3400    ;== ADC trigger

330400    ;== DAC write

A30000 ;To read channel 0

A30000 ;To read channel 0

A30000 ;To read channel 0

]

over 13 years ago

0 Tom Hendrick over 13 years ago

TI__Guru**** 181351 points

Hi Roxana,

Can you provide more detail on how you have the AMC7812 connected? Are you using the AMC7812EVM-PDK or do you have your own processor and software running the EVM?

0 Roxana Ponce over 13 years ago in reply to Tom Hendrick

Prodigy 30 points

Hi,

I'm using the AMC7812EVM, and i'm sending the configuration through the SPI port, with a microprocessor that follows the steps I posted. The problem I'm having, is that I need to retrigger the AMC, in order to read the new value found in the ADC, it doesnt updates its value itself.

0 Ruben over 13 years ago in reply to Roxana Ponce

TI__Intellectual 1395 points

Hi Roxana,

Do you have access to the DAV pin on the AMC7812? If so I would start by making sure there is a constant 1us pulse (low) indicating that the ADC is properly set up in auto-mode and continuously converting.

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AMC7812 ADC Continuous mode not working (SPI)