NS16C2752: Communication problems with the SD card

shuhei hayashi

Part Number: NS16C2752

Hi-All,

An abnormal behavior has occurred with the SOUT1 terminal of the NS16C2752TVS.
Specifically, a problem occurred where communication with the SD card was not possible immediately after the NS16C2752TVS was started up.
Please see the dollowing questions an waveform.

1)A problem occurred where communication with the SD card was not possible immediately after the application was launched.
Is it possiblity for SOUT1 to spontaneously go low even if no register access is performed after POR startup?
Also, is it possiblity for the TX line (SOUT1) to change between High-Low-High during register initialization?
Please see the enlarged waveform.

2)Are there other instances where the TX line(SOUT1)toggles once after a certain period of time has passed since powering on, without changing the register settings during initialization?
For example, is there a way to prevent this toggle phenomenon by adjusting the register settings?

Best regards
Shuhei Hayashi

6 days ago

0 BOBBY 5 days ago

TI__Guru* 80301 points

Shuhei,

I'm not aware of a condition where SOUT would toggle without any sort of write to the THR.

Do you have a schematic I could review?

Is there anything else connected to the SOUT net?

If you put a weak 47k pull up resistor on Sout, do you still see the Sout toggle?

-Bobby

0 shuhei hayashi 4 days ago in reply to BOBBY

Prodigy 200 points

Hi- BOBBY,

Thank you for your answer.
I have a customer's circuit diagram.
Since I cannot publicly share the customer's circuit diagram, please kindly contact me via my private email.
I will share the circuit diagram with you.

Best regards,
Shuhei Hayashi

0 BOBBY 4 days ago in reply to shuhei hayashi

TI__Guru* 80301 points

You can email it to me at duynguyen@ti.com
-Bobby

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NS16C2752: Communication problems with the SD card