NTAG5 Link ED pin behaviour

[komal18apr]

Hi,

I am in process of developing a project with Ntag5 link where EEPROM memory Read Write is done successfully with ED pin configured simply as Field detect with ED_CONFIG_REG value 0001b. Now, I want to use SRAM transfer with pass through mode. Procedure followed as per document of NFC AN12364 on both side, i.e. firmware and app. No communication happened. I have noticed that when ED pin is cleared by microcontroller by writing 1b to ED_PIN_CLEAR register do not work, pin remains low. What may be the possible reasons? Can you suggest any method to debug this? As this pin remains low, microcontroller do not get to know about SRAM is written or not. Will you please suggest any tool where I can debug microntroller firmware without my app but with the tool/app to be used for pass through mode.

[jimmychan]

Please check:

• Ensure the SRAM_ENABLE bit is set in the configuration register.
• SRAM is only available when VCC_SUPPLY_OK = 1b.
• The ED pin must be configured for SRAM write detection, not just field detection.
• Check that ED_CONFIG_REG is set to 0010b or 0011b for SRAM-related events

[komal18apr]

Thank You for the reply Jimmychan,

SRAM_ENABLED bit is set already and we are checking when VCC_Supply is Ok. Now, as per datasheet, SRAM related operations are valid whenED_CONFIG_REG is set to 0100b or 0011band not ED_CONFIG_REG is set to 0010b or 0011b.

Kindly confirm the values.

[jimmychan]

Are you trying to implement like the Figure 2. at page 11 in AN12364? 

Also, for your reference. It show some examples may useful for you.

03-Webinar-slides-How-to-develop-with-NTAG-5.pdf

[komal18apr]

Hi Jimmychan,

Can you please reply on the query related to flags asked in my previous reply.

I have solved my problem with the help of document you provided for pass-through mode by using flag bits value as 02, and it is not supporting 12 value actually, so I need some more details related to flag bits used in commands of NTAG5.

Waiting for your reply.

[jimmychan · Accepted solution]

The flags are defined in table3,4,5 in ISO15693-3 standard.

[komal18apr]

Thank You so much Jimmychan.. This helped a lot.

[komal18apr]

Hi Jimmychan,

I want to implement like figure on page 9 first, then implement like the Figure 2. at page 11 also to complete the pass-through mode.

Thanks for sharing another pdf for example understanding. It helped a lot in understanding many things. And I hope, I am nearer to the solution as well.

I want the explanation of flags byte, which is always the first byte to be sent in any request instruction just like given in that example pdf on page 41, attaching screenshot here, highlighted in red block.

If there is any specific document explaining about those flags in every condition of operation with NFC tag, please share.

Have a good day.