Can NTAG I2C plus inform the updated address of EEPROM to MCU

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Can NTAG I2C plus inform the updated address of EEPROM to MCU

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andy_kim
Contributor IV

Hello.

User would write to a certain address wherever they want on EEPROM by NFC Interface in normal mode.

Then, MCU is gong to read EEPROM by I2C interface.

 

What I want to know is below

MCU can know only the updated address on EEPROM and read only the information of the updated address on EEPROM via I2C interface? if so, How it works?

 

As long as I know, FD is just trigger to signal to MCU for some events.

 

If you need more information, please let me know.

 

Thanks,

Andy

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688 Views
Kan_Li
NXP TechSupport
NXP TechSupport

Hi @andy_kim ,

 

Actually this function is more like an implementation on application level, both the RF and NFC side should know the space used for exchanging data, and MCU may monitor this space periodically or on the event of FD line.

 

Hope that makes sense,

 

Have a great day,
Kan


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681 Views
andy_kim
Contributor IV

Hi, Kan
Thank you for your comment.

Let me ask you further question.

When NFC writes something to EEPROM of NTAG I2C plus,

MCU can detect the writing operation by FD line.

But I don't know how NTAG I2C plus can inform the right updated address to MCU via I2C without scanning all of address of EEPROM.

Is it available for NTAG I2C plus to send only the updated address of EEPROM on I2C Data line to MCU?
I'd like to know what mechanism can make the function work.


Thank you,
Andy

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675 Views
Kan_Li
NXP TechSupport
NXP TechSupport

Hi @andy_kim ,

 

I am sorry, but maybe there is some misunderstanding. The FD pin event can be either of the following:

NTAG i2c FD events.png

but none of them inform the write operation. the only way can be both the I2C and NFC side knows the address they use for communication, and I2C side polls the address when FD event happens.

 

Hope that makes sense,

 

Have a great day,
Kan


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andy_kim
Contributor IV

Dear Kan,

 

Let me make it sure.

 

There is no way to inform only the updated address to MCU via I2C after writing EEPROM by NFC interface.

MCU have to poll all of EEPROM address to find the updated address. right?

 

Thanks,

Andy

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663 Views
Kan_Li
NXP TechSupport
NXP TechSupport

Hi @andy_kim ,

 

The device can not tell the MCU the exact updated address, but there is still some trick available to implement it in the application layer.

Last NDEF block.png

if this register is updated, that means there is write operation happened. From NFC application side, it may read the last page of this I2C block after writing to trigger a FD event to MCU side.

 

Hope that helps,

 

Have a great day,
Kan


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