Intel® Quartus® Prime Standard Edition User Guide: Debug Tools

ID 683552
Date 9/24/2018
Public
Document Table of Contents

5.3.2.5. Signals Unavailable for Signal Tap Debugging

Not all the post-fitting signals in your design are available in the Signal Tap: post-fitting filter in the Node Finder dialog box.

You cannot tap any of the following signal types:

  • Post-fit output pins—You cannot tap a post-fit output pin directly. To make an output signal visible, tap the register or buffer that drives the output pin. This includes pins defined as bidirectional.
  • Signals that are part of a carry chain—You cannot tap the carry out (cout0 or cout1) signal of a logic element. Due to architectural restrictions, the carry out signal can only feed the carry in of another LE.
  • JTAG Signals—You cannot tap the JTAG control (TCK, TDI, TDO, and TMS) signals.
  • ALTGXB IP core—You cannot directly tap any ports of an ALTGXB instantiation.
  • LVDS—You cannot tap the data output from a serializer/deserializer (SERDES) block.
  • DQ, DQS Signals—You cannot directly tap the DQ or DQS signals in a DDR/DDRII design.