Type: Answers

Area: Component



Why does the TCK frequency setting of the USB-Blaster II download cable revert to the default value of 24 MHz after being changed?

Description

Even if the TCK frequency setting of the USB-Blaster™ II download cable is changed using the jtagconfig command, as described in the related solution, the frequency setting may revert to the default value of 24MHz in the following cases:

  • A jtagconfig command is executed when the USB-Blaster II download cable is removed from your PC.
  • A jtagconfig command fails to recognize the USB-Blaster II download cable and shows an error.
  • A JTAG operation like Hardware Setup is executed from the Quartus® II software when the USB-Blaster II download cable is removed from your PC.

Workaround/Fix

You can obtain the TCK frequency setting in the USB-Blaster II download cable using the following command:

jtagconfig --getparam <cable> JtagClock

<cable> is the USB-Blaster II download cable to be modified.

If the frequency is not your desired value, set it again.