Article ID: 000077690 Content Type: Troubleshooting Last Reviewed: 09/11/2012

Are there any known errors in the Stratix and Cyclone Configuration chapters with reference to the external pull-down resistor value recommended for the JTAG TCK signal?

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Description Yes. The JTAG TCK pull-down resistor value is incorrectly specified as 10k-ohms in the Stratix® and Cyclone® devices Configuration chapters. The correct external pull-down resistor value is 1k-ohm. This stronger resistor ensures that the TCK signal is biased at a logic low level despite the weak internal pull-up on this pin. The internal pull-up ranges from 20k-ohms to 40k-ohms across process, voltage and temperature.

Future versions of the Stratix and Cyclone Handbooks will be updated accordingly.

Related Products

This article applies to 2 products

Stratix® FPGAs
Cyclone® FPGAs