• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 54 subscribers
  • Views 772 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

Problem with CC112X Manchester together with existing CC1020 devices

Knud Tangsgaard
Prodigy 70 points
Other Parts Discussed in Thread: CC1125, CC1020, CC1175

Hello...

 

I am working on new wireless project using the CC1125 chip, which must be compatible with existing units unit CC1020 + Manchester coding.

Existing units use 0xAA as preamble and D391 for sync. word.

 

The CC112X/CC1175 User guide page 24, says that CC1125 packet handling can be used for systems which use Manchester coded preamble + sync. Word, by manual encode Sync word and using preamble mode 10b or 11b.

 

But I think there is problem with the available pre amble modes:

  Mode 10b = 0x33

  Mode 11b = 0xAA

 

 

The existing system send 0xAA as preamble, wich also are Manchester coded – so, 0xAA must send out 0x99 0x99.

 

But 0x99 is not available as pre amble mode?

 

How to setup CC1125 for Manchester coding compatible with CC1020?

 

Regards

Knud Tangsgard

  • 0
    TI__Mastermind 39860 points
    CC1125 does not MC encode preamble and sync.

    One alternative:
    On the TX side you can do the MC encoding in SW. Switch off automatic insertion of preamble and sync word and write the preamble + sync directly to the TX FIFO. Suggest you also do the CRC calculation on the data payload (not including preamble and sync) in SW and write this to the TX FIFO. Switch off automatic CRC calculation.

    On the RX side write the MC encoded sync word into registers SYNC3,2,1,0. You can enable automatic CRC check
  • 0 in reply to Sverre
    Prodigy 70 points

    Thanks for fast and very usefull reply!

    I did not think of the possibilty to switch off both preamble and sync. word - think this should - I'm going for this solution.

    Best regards

    Knud