• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 53 subscribers
  • Views 513 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.

Update time of Channel Filter Data Valid bit

Abdulhussain Songerwala
Prodigy 110 points
Other Parts Discussed in Thread: CC1120

Hello,

          I am using CC1120 transceiver in my application and need to read its temperature(digital readout). I have updated the code according to Rev. C(swra415c) for the same. According to the User Guide the CHFILT_STARTUP_VALID bit updates after 16 channel samples. I wanted to know how to calculate the time taken by this bit to update as I do not want the code to wait infinitely for the bit to set. Hence I can set a timeout value accordingly.

  • 0
    TI__Guru**** 317180 points
    I have found a couple of different numbers on the delay.

    The delay is deterministic and the bit will always be updated. If you want an exact number I would recommend measuring the delay with your settings to ensure that the timeout is set correctly.
  • 0 in reply to TER
    Prodigy 110 points
    First of all thank you for your reply. I plan to use a counter to check the number of times the value had to be read before the bit set. Does that sound fine?
    Also, theoretically is it ever possible that the bit does not set? For example if something has gone wrong with the internal temperature sensor. In which cases would this happen?
  • 0 in reply to Abdulhussain Songerwala
    TI__Guru**** 317180 points
    To make a failsafe code it makes sense to have some sort of check to ensure that the code doesn't hang. But for me it sounds better to just have a timer or similar that gives a timeout if the temperature readout takes much longer than expected. What did you plan to use as the tick for the counter? The samples are internal to the radio so you would not get any triggers from the CC1120 to use as an input to the counter.
  • 0 in reply to TER
    Prodigy 110 points

    Referring to Rev C of the CC Temperature Sensor application note, I plan to increment a counter everytime I remain in the do-while loop. Finally I will check the value of this variable to get some idea. Of course the value will be checked multiple times before finalizing one final value. Does this sound ok?