IWR6843AOP: UART Flash Programming : No answer to break command

Nicolas Delmas

Part Number: IWR6843AOP

Hi,

I'm currently debugging a custom board that implements the IWR6843AOP sensor that uses the xWR6843AOPEVM board as reference.

The current state of the solution is :

NRESET comes up after all power rails are stable (Using a big RC filter)

VBGAP Comes up

WARMRESET goes down for 8 mS

I can see some activity on the CS pin of the QSPI Flash memory

SOP0 is tied to 3V3

SOP1 is tied to GND

SOP2 is controled by a DIP switch, currently tied to 3V3

When sending a low baudrate 0x00 (Break command) on ball V16, the TX channel (Ball U16) doesn't react at all, while it should send back the ACK response.

Is there anything I am missing ?

Thanks,

Nicolas Delmas

Edit :

When SOP2 is tied to GND, the chip echoes back what I send it over UART.

over 3 years ago

0 E. Shareef over 3 years ago

TI__Genius 16310 points

Hello,

Thank you for reaching out to Texas instruments. A team member will assist you with your query shortly.

-Shareef

0 Abhed Misra over 3 years ago

TI__Genius 13805 points

Hi,

Can you please again confirm the state of the SOP pins on your board?

Regards

+1 Nicolas Delmas over 3 years ago in reply to Abhed Misra

Prodigy 10 points

Thank you for your answer,

I actually found the issue this morning after reading this post : https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1035317/iwr6843aop-can-not-use-external-xds110-flash-iwr6843aop-with-uart

It seems like the PCB house made a mistake and put 33.2kOhms resistors on the SPI lines of the flash instead of the specified 33.2 Ohms, I changed the resistors and everything works correctly, I was able to get the sensor programmed and it returns coherent values !

Thank you again for your help.

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IWR6843AOP: UART Flash Programming : No answer to break command