CC1200: CC1200 link rate mismatch

Alex Strelbytskyy

Expert 1900 points

Part Number: CC1200

Hello,

If transceiver is supposed to receive data form sources that have slightly different link rates, The User's Guide recommends to adjust TOC_LIMIT field in the TOC_CFG register (page 98).

It is not clear what threshold should be used for the settings 01 and 11. Why units for thresholds are in % ppm? What are the thresholds in Hz for the link rate e.g. 200kHz ? Do you have any recommendations for the selection of TOC_PRE_SYNC_BLOCKEN and TOC_POST_SYNC_BLOCKEN when TOC_LIMIT is not 0?

Thanks,

Alex

over 2 years ago

0 TER over 2 years ago

TI__Guru**** 317180 points

The recommended settings will be dependent on the datarate error.

Could you cover in more detail what the data rate error is in your setup?

0 Alex Strelbytskyy over 2 years ago in reply to TER

Expert 1900 points

hello TER,

CC1200 transceiver that has link rate 172.800 kbps should receive from two sources that have link rates 172.800 kbps and 173.076 kbps.

Thanks,

Alex

0 TER over 2 years ago in reply to Alex Strelbytskyy

TI__Guru**** 317180 points

From the UserGuide:

Based on the numbers given you should be able to receive with nominal setting.

0 Alex Strelbytskyy over 2 years ago in reply to TER

Expert 1900 points

in real system CC1200 drops packets when packet size is greater 50 bytes for the default TOC_LIMIT=00 if link mismatch 0.16%. I have to use TOC_LIMIT=01. In this case there is no packet drops for for the source clock with error 0.16%, but there are dropped packets for the source with clock error 0 %.

What settings for TOC_PRE_SYNC_BLOCKEN and TOC_POST_SYNC_BLOCKEN could you recommend?

0 TER over 2 years ago in reply to Alex Strelbytskyy

TI__Guru**** 317180 points

I'm used to the "replay" button is to the left but sometimes it's the "thinks resolved", hence a wrong press.

I see that for phys with 1 % datarate tolerance we have used TOC_CFG = 0x4E

Sub-1 GHz

Sub-1 GHz forum

CC1200: CC1200 link rate mismatch