Subj.
"Some cores have JTAG debug port, like Triscend, Cygnal (Silicon Laboratories), so you should have several JTAG debug adapters." Because JTAG works in a chain, it should be possible to use only 1 debug adaptor ... in theory, at least. Especially with Triscend, which allows you to debug remotely over your LAN. I have enough Triscend boards knocking around - I keep thinking I should try this one day...