Honored ContributorIC is getting heated if i change the signals from output of lpm_add and d flip flop.
The output of lpm_add goes to dff and so the IC gets heated but if i change the signals IC is not heated. Whats coudl be the problem?
Honored ContributorCould be a damaged IC (maybe from static). I have found that many times with some of my circuits with a signal prone to ESD.
To test: Change the I/O pins to other unused pins (if possible), recompile and configure. If it still gets hot then I don't know. If not then something is wrong at the I/O drivers. In some of my boards my UART's Rx pin got damaged. Whenever I use the pin the chip gets red hot. If I move the function to the pin just next to it the chip cools down. Very disheartening to think you have an expensive chip in your board with something similar to spinal cord damage connected to a healthy brain :-) The nice thing about an FPGA is the ability to re-route the pins. Since I found this problem on a 1C6 design I provide breakout pads from unused pins. If my customer breaks a I/O pin (which is quite possible in the environment it is used) I just recompile the design, cut the track and solder it to the breakout pad/pin. Note that Quartus will rarely compile something that will result in such a horrible condition. Last thing. Also check to what your I/O reference is set to (1.5V or 3.3V). Could also cause funny things to happen. Victor http://www.zerksus.com (http://www.zerksus.com)
