Where is the Signaltap JTAG usb driver documentation ?

[Altera_Forum]

Hello, 

 For some reasons I would like to integrate some signaltap functions in my own application. Some basic functions such as setting a trigger on a signal and receiving the signals' values. This will be very useful for my automatic tests and/or comparing several boards (by calling several USB devices in a single program)  May I be able to see it and use it without Signaltap ? Where ?  Thank you very much,

[Altera_Forum]

There's no documentation about Signaltap JTAG interface. You find some documentation about the debugging infrastructure in Virtual JTAG IP user guide. https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/ug/ug_virtualjtag.pdf 

 You can also search the forumfor threads about "virtual JTAG".

[Altera_Forum]

Thank you for your answer FvM but I'd like something more high level such as calls to the usb driver (usbmon). Altera usb driver is already supposed to manager the JTAG protocol. 

To be precise, I'd like to replace Signaltap by my own program. Anyway looks like there is no such documentation.

[Altera_Forum]

Virtual JTAG is what you'd use to "replace Signaltap". This gives you access to the JTAG interface so you can create your own debugging logic that can be accessed via JTAG. USB is not JTAG. If you're referring to building your own USB-Blaster (JTAG to USB converter), you can look at recent Altera dev kits that have the USB Blaster hardware on the board (instead of a separate "pod" that attaches to the FPGAs 10 pin JTAG connection).

[Altera_Forum]

Virtual JTAG is one of many source level debugging node types. It's a generic type intended as interface to user specific debugging functions, and the only fully documented SLD node type. 

 Each SLD node type has it's own set of ir_shift and dr_shift commands to operate it.  As discussed in this previous thread http://www.alteraforum.com/forum/showthread.php?t=2199, the regular access to the Quartus JTAG stack is provided by dlls that can be basically called in user applications if you understand the interface.