Nios® II Embedded Design Suite (EDS)
Support for Embedded Development Tools, Processors (SoCs and Nios® II processor), Embedded Development Suites (EDSs), Boot and Configuration, Operating Systems, C and C++
Intel Support hours are Monday-Fridays, 8am-5pm PST, except Holidays. Thanks to our community members who provide support during our down time or before we get to your questions. We appreciate you!

Need Forum Guidance? Click here
Search our FPGA Knowledge Articles here.
12453 Discussions

How to check if ALTERA USB-Blaster is connected

Honored Contributor II

Hi all, 


I am looking for a way to programmatically determine if the Application is starting on its own or if it gets started with a connected ALTERA USB-Blaster (JTAG). 


Until now I had two separate Project configurations in the IDE containing the defines _DEBUG and NDEBUG. 



project details: 

- Nios2/f 

- ACDS 13.0sp1 

- FreeRTOS 


Thanks for your suggestions!
0 Kudos
2 Replies
Honored Contributor II

I've always used a GPIO with the built-in pull up enabled. It's connected to an external switch that grounded it. Grounded indicating debug mode, open is non-debug mode. The software could read that switch at startup to determine if you were running in debug mode or not. 


If this isn't available, you might try a different scheme. I've not used this but it's easy to see if it works or not. Write some characters to the JTAG uart. If the transmit buffer never empties, no JTAG is connected. Don't write more than the FIFO holds or the software will hang waiting for the data to go out (which it never will).
Honored Contributor II

Thank you for your response! I'll try that as soon as possible.