TRF7970A: Mode 0 code for TRF7970A EVM

Hello Debojyoti,

The only Direct Mode 0 code we offer is: www.ti.com/.../TRF796X_TRF7970X_MIFARE_12_2013

Note that while we offer this code, we do not actively support DM0 applications, so you will need to take what is given and apply it on your own.

Thank you Ralph for providing the link. I have requested TI to share the files. Hope the request will be approved.

Just to give you little detailed background :-

I am representing a small software service company based in Kolkata, India.  I am working for our client with their innovation center at Silicon valley. Our client manufacture proprietary NFC tags (subset of ISO/IEC 14443) using their printed technology. Currently these tags are only working in tag talk first mode and you can only read them (no write). Now they are developing writable tag with proprietary standard.

Earlier we have bought  multiple TI TRF7970A EVM boards and developed the client tag reader firmware for our client successfully using DM1. Obviously I have taken help from example base codes from TI document

There were no transmission of read request from TRF7970A as the above tags will spontaneously transmit if they get power from reader.

Now we have new requirement of writable tag. We need to send proprietary read, write, enable, disable etc commands using Modified Miller code at 106 kbps. The printed IC resource is very limited. So we decided to issue very small size commands like  4 bit and 1 bit command / data. Example :-

0 (Sof), 0000 (data), no eof  

0 (Sof), 1111 (data), no eof  

0 (Sof), 0 (data), no eof  

0 (Sof), 1 (data), no eof  

I am using SDM mode. But I am unable to eliminate the eof bit (which is always 0) . 

So, I am not sure this can be done using SDM (I have already tried few days).

And now thinking to use DM0 for transmitting the very short commands.

BR,

Debojyoti

Images_ModifiedMillerCode_4bit_12Nov2018.zipJust to be more accurate :-

Sof is not start of frame - it is start of communication => Sequence Z

eof is end of communication

Hello Debojyoti,

This sounds like a proprietary RFID technology so it is outside of the range of our support offerings with our devices. We are focused on the NFC market which has well-defined standards and promotes high interoperability. The only proprietary RFID technlogy we support is MIFARE Classic as it is the largest such technology and still very popular. Beyond that, we will not support other non-NFC applications. The resources provided are all we will offer for this application.

Awaiting approval from TI for downloading www.ti.com/.../TRF796X_TRF7970X_MIFARE_12_2013

If not approved, we are going to use NXP or other chip for reader.

Thanks in Advance,
Debojyoti

Dear Ralph ,

Just for your information, I am working on behalf of a company called Thin Film Electronics for their tags.

BR,
Debojyoti

Hello Debojyoti,

It should have no issue being approved but the process can be a bit slow. On our teams end the request hasn't made it to us yet, but there is another approval step between your submission and us getting the request. If you still don't have approval by this time tomorrow let me know.

Hello Ralph,

Actually I was using my gmail account to login in this forum. TI said they are not going to share the code in personal account. So, I changed my login info to my company email address and again requested for TRF7070A Mode 0 code. Hope TI will approve that !

BTW, have you got chance to look into my screen shots attached in earlier post ? Just I was wondering my task can be done using SDM. Things are nearly done in SDM, only I have to remove the end of communication (Z followed by Y sequence). Otherwise I can send 4 bit or 1 bit commands already using SDM.

Now, I am trying DM0 for few days but unable to modulate the 13.56 MHz carrier. The signals in MOD pin is as per my choice. Also ASK/OOK pin is fine. Let me wait for TI code for Mode 0 !

BR,
Debojyoti

Hello Debojyoti,

I have not and will not review those screenshots, as stated your application is outside of what we will support. We are not going to investigate if SDM can work for your application, but you are free to try using it by following our app note on how to use it for Mifare Classic: http://www.ti.com/lit/pdf/sloa214

The gmail vs company email makes sense, again if you don't get the files within a couple business days then please let me know.

Yes. I have got the code yesterday. Many thanks. Definitely I shall look into it. 

However before getting the code I have successfully configured DM0 transmission in slow mode using MOD pin and OOK. I was missing the point that Slave Select to be put low during entire transmission time.  Now I have to look into timing as per our client spec.

Many thanks again for helping.

Best Regards,

Debojyoti