What inexpensive or free tools could you recommend to view and control pin states via JTAG boundary-scan?
I'm aware of full-featured boundary-scan products that cost tens of thousands of dollars and used in manufacturing houses mainly. I want a simple inexpensive tool to occasionally check few suspected pins if they are soldered correctly; to light LEDs on a board without writing any firmware for MCU/CPLD/FPGA; to see if pressing a button on a board changes the appropriate pin state, etc.
Take a look at TopJTAG Probe -- http://www.topjtag.com. It seems intended to what you've described. A good news it works with several popular JTAG pods so you probably don't need to buy additional JTAG pod but use yours existing.
Another option might be the free Buzz utility offered at Jtag Live That also works with Xilinx and Alter cables and possibly FTDI chip based cables.
It allows you to 'watch'a signal using SAMPLE mode and buzz out mutiple connection between JTAG devices - pretty neat really.
Another option would be NEBULA. We're using it not just for pins but for fpga user defined registers. It's free. Uses Xilinx and Intel/Altera USB cables. Uses 1149.1-2013 JTAG Tcl scripting language Intellitech NEBULA for iJTAG 1149.1-2013
