Intel® MAX® 10 FPGA Design Guidelines

ID 683196
Date 10/19/2020
Public
Document Table of Contents

1.5.3.4. Verify the JTAG pin connections to the download cable header

A device operating in JTAG mode uses the required TDI, TDO, TMS, and TCK pins. The TCK pin does not support internal weak pull-down.

Connect the TCK pin to an external 1-kΩ to 10-kΩ pull-down resistor. The TDI and TMS pins have weak internal pull-up resistors. The JTAG output pin (TDO) and all JTAG input pins are powered by VCCIO. The voltage range is 1.5 V to 3.3 V.

The download cable must be powered at 2.5 V when VCCIO of the JTAG pins are powered at 2.5 V to 3.3 V to prevent voltage overshoot because JTAG pins do not have internal PCI* clamping diodes. The TCK pin must be pulled to ground. If the VCCIO of the JTAG pins are powered at 1.5 V or 1.8 V, the download cable should be powered by the same VCCIO.