CC1125: cc1070 migration

I don't think we have a migration guide here. CC1070 gives out a bit stream but in CC1125 the received data can be read out from the FIFO.

Does the protocol you are using now use preamble + sync word? Knowing the protocol would help to guide you to what you can do. 

Thanks.

I don't have any details yet.

I suspect the idea will be to change as little as possible (initially, at least) - so can the CC1125 still give the same bit stream output ?

Yes, CC1125 can give bit stream out, see transparent mode in the User Guide. Note that this bit stream has some jitter and need to be oversampled.

But to get the best performance I would recommend using the FIFO if possible. 

Any more details you/ I can provide here? 

I've not had any more details yet.

But, doing some background reading, the CC1070 is transmit only - no receiver.

So  the CC1070 is receiving the bitstream from the Host MCU - rather than "giving it out".

I guess that will remain the same.

Part of the reason for the update is to give the possibility to add receiving.

So is it possible to receive via the FIFO while still using the bitstream to transmit?

It's not a high speed nor high data volume system.

For TX it should be fairly straight forward. I highly recommend using the FIFO in TX since the effort of implement it is low. Basically yoo need to write the packet you want ot the FIFO and send the STX strobe.

Since you don't have a RX code today I would recommend using the FIFO also here. On the CC1125 product page you can find some software examples to get you started.

The protocol is POCSAG.

The idea, at least to start, is to make as little change as possible; ie have the CC1125 as just a "drop-in" replacement for Tx only.

For that, it looks like the Synchronous Serial Mode would be the way to go - yes?

Elsewhere, it is said that the CC1070 is the Tx half of the CC1020:

https://e2e.ti.com/support/wireless-connectivity/other-wireless/f/667/t/73823?tisearch=e2e-sitesearch&keymatch=cc1070

The "CC1020 MCU Interfacing" link there is broken, but google finds this:

http://application-notes.digchip.com/001/1-2153.pdf

and this seems to be an update:

http://www.farnell.com/datasheets/1675037.pdf

EDIT

Those documents make reference to associated code files - where are they now ?

I get the impression that you don't know the CC1070 implementation well? 

Yes, you should be able to use "Synchronous Serial Mode" for this. 

And yes, the datarate is given differently on CC1020/ CC1070 compared to every generation after, including CC1125.

What files(s) do you need for the CC1070? Are you planning to change some code on the CC1070 side? I assume that the SPI interface is different on the CC1070 and CC1125 and you have to set the registers meaning that you have to write some new code to access the CC1125.  

TER said:

I get the impression that you don't know the CC1070 implementation well? 

Indeed.

TER said:

And yes, the datarate is given differently on CC1020/ CC1070 compared to every generation after, including CC1125.

how does it differ?

TER said:

Are you planning to change some code on the CC1070 side?

The plan is that the CC1070 will be replaced by a CC1125 - so code will need to be changed to accommodate this.

TER said:

I assume that the SPI interface is different on the CC1070 and CC1125 and you have to set the registers meaning that you have to write some new code to access the CC1125.  

Indeed.

Since you are not familiar with these devices is to use SmartRF Studio to check that you have found the correct settings for CC1125 in TX. 

And since you need to re-write the software anyway, I would recommend you to look into using the FIFO in TX since you basically want to use this in RX later. 

TER said:

And since you need to re-write the software anyway, I would recommend you to look into using the FIFO in TX since you basically want to use this in RX later.

The brief from the client is to change as little as possible. But I guess this is a discussion to have...

Presumably, the RX could still be done over the Synchronous serial interface - as for a CC1020 ?

TER said:

What files(s) do you need for the CC1070?

were you referring to:

I said:

Those documents make reference to associated code files - where are they now ?

In which case that was more about the CC1020 - for the RX side.

TER said:

using the FIFO in TX since you basically want to use this in RX later.

It seems I have over-stated the requirement.

The requirement is just to do listen-before-transmit - not actually receive any data.

Sorry about that.