Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 1673 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TLC3578 Mode 00

Stephen Miller
Prodigy 90 points
Other Parts Discussed in Thread: TLC3578

I am trying to code up an FPGA to communicate with the TLC3578 via Mode 00 or one-shot mode.   Here is my problem, I write out the SPI code to select an analog input channel and wait for the conversion to complete.  Now to actually get back the analog measurement, I have to do another SPI transaction.  The problem is finding a "good" dummy command to get this data back.   If I issue the same select analog inpu channel command, then I waste time doing another conversion.  It seems what is needed is a NOP instruction that just allows access to the previous command output data.  However, I do not see anything like this in the Command Set.  What an I overlooking?

Thanks.

 

  • 0
    TI__Guru**** 174166 points

    Hi Stephen,

    Assuming you are going by figures 11 or 12, you are not overlooking anything.  That is simply the way these devices were designed to work if /CS or FS initiates the conversion.  If you can use the CSTART pin to initiate the conversion as in Figure 13, the 'select channel' command will give you the conversion results without initiating a new conversion.  The command you send will setup the MUX for the channel you wish to convert the next time you actually pulse CSTART.