XIO2001: Pull-up strength on JTAG_TRST signal

JosefMieslinger

Part Number: XIO2001

Dear TI Team,

we are using XIO2001 in our design and we experience some issue with the JTAG Interface. We expect it is some issue with JTAG_TRST signal.

Can you please provide us some information about the strengh of integrated pull-up resistor for this signal?

Thanks and best regards,

Joe

over 5 years ago

0 Davor Glisic over 5 years ago

TI__Expert 8165 points

Hello Joe,

I don't have an exact value at the moment, but based on the IOZP spec for the 3.3V I/Os, I’m estimating it is in the 50kohm to 100kohm range. Would this range be helpful or a more precise value is needed?

Regards,

Davor

0 JosefMieslinger over 5 years ago in reply to Davor Glisic

TI__Intellectual 2170 points

Hi Davor,

thanks for the quick respone. We want to pull down the signal to disable the TAP controller during normal product operation, but still be able to access the JTAG with a tool. So if we pull-down JTAG_TRST with a resistor <50k, the TAP controller should be safely disabled, correct?

Thanks!

Joe

0 Davor Glisic over 5 years ago in reply to JosefMieslinger

TI__Expert 8165 points

Hello Joe,

With the IOZP max spec of 100 uA, a <10k pulldown resistor is needed to ensure TAP controller is disabled.

Regards,

Davor

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XIO2001: Pull-up strength on JTAG_TRST signal