RT1176 JTAG_MOD pin

[karaca]

Hi,

We designed a custom board with IMXRT1176. We connected to board all JTAG pins. But JTAG_MOD pin is float. We can not make JTAG connection. What can you suggested us?

[karaca]

Hi Omar,

Thanks for your information. JTAG_MOD is float in our hardware. Can we change JTAG_MOD pin to float with software? We can use USB and UART communications but we need JTAG.

Thanks.

[Omar_Anguiano]

Unfortunately, JTAG_MOD needs to be externally connected to GND so JTAG works correctly. 

If you have more questions do not hesitate to ask me.
Best regards,
Omar

[karaca]

Hi Omar,

We connected JTAG_MOD pin to GND with rework. But we still can not connect JTAG. Our connection in below.

Do you have any suggestion? 

Thanks. Regards.

[Omar_Anguiano]

It is important that you´ve followed the recommendations from the Hardware Development Guide. External resistors can be used with all JTAG signals except for JTAG_TDO, but they are not required.
Did you burn any fuse?

If you have more questions do not hesitate to ask me.
Best regards,
Omar

[Omar_Anguiano]

Hello
Hope you are well.

When JTAG_MOD is low, the JTAG interface is configured for a common software debug, adding all the system TAPs to the chain.
When JTAG_MOD is high, the JTAG interface is configured to a mode compliant with the IEEE 1149.1 standard.
JTAG_MOD shall be externally connected to GND for normal operation in a system. The termination to GND through an external pull-down resistor is allowed using a 4.7-kΩ resistor.

If you have more questions do not hesitate to ask me.
Best regards,
Omar