PLL not working on 10M16DCU324 FPGA_Quartus toll - PLL not working on 10M16DCU324 FPGA_Quartus toll Hi, I have designed board with 0M16DCU324 having 25MHz eternal clock source. I am trying to test PLL by toggling LED with PLL generated clock but i am not able to toggle the LED. Once i revived schematic i found that 2 out of 4 VCCD_PLL pins on my board are not connected. earlier design i was using 10M02DCU324 here my PLL was working as this device is having only 2 PLL. Does PLL to function need to connect all VCCD_PLL to 1.2V? is there any way to configure specific PLL blocks which has VCCD_PLL pins connected to 1.2V? I have VCCD_PLL1 and VCCD_PLL2 connected to 1.2V and remaining two are floating. I am suspecting that as all of my VCCD_PLL are not connected to 1.2V that's why my PLL is not working, is this understanding correct? Thank you Replies: Re: PLL not working on 10M16DCU324 FPGA_Quartus toll Hello Thanks for sharing IO pin details, i have verified it and all the GND, VCC, VCCA, VCCD_PLL and VCCIO pins for 10M16DCU324 are connected as per shared details. Actually i have migrated from 10M08DCU324 to 10M16DCU324 so here both the devices have similar pins for GND, VCC, VCCA, VCCIO, only difference is VCCD_PLL2 and VCCD_PLL3 are additional pins in 10M16DCU324. Replies: Re: PLL not working on 10M16DCU324 FPGA_Quartus toll Hi, As mentioned by FvM, according to the Pin Connection Guideline, you must connect all the VCCD_PLL pins 1.2V power supply. So I think your understanding is correct: you have to connect all the VCCD_PLL pins to power supply to make sure the PLL works normally on 10M16DCU324. By the way, it seems you were trying to migrate the 10M02 board to 10M16. By comparing the Pin-out of 10M02DCU324 and 10M16DCU324, you can see there are multiple different pins, including GND, VCC, VCCA, VCCD_PLL and some VCCIO. Please also check if these pins are correctly connected for 10M16 as well. 10M02DC: Pin Information for the MAX® 10 10M02DC Device - XLSX Format (Alt. Format PDF) 10M16DC: Pin Information for the MAX® 10 10M16DC Device - XLSX Format (Alt. Format PDF) MAX 10 PCG: MAX® 10 FPGA Device Family Pin Connection Guidelines Best Regards, Xiaoyan Replies: Re: PLL not working on 10M16DCU324 FPGA_Quartus toll I tried with my 10M08 FPGA device and it is working there, where only VCCD_PLL1 and VCCD_PLL2 is connected to 1.2V. It might be working as there are only 2 PLL modules for 10M08 keeping NC for PLL3 and PLL4. I tried with my 10M16 FPGA device and it is not working there, where only VCCD_PLL1 and VCCD_PLL2 is connected to 1.2V. It might not be working as there are 4 PLL modules for 10M16 and i made NC for PLL3 and PLL4 VCC pins. Is my understanding correct? Replies: Re: PLL not working on 10M16DCU324 FPGA_Quartus toll Hi, you are starting 3 threads where you should start one. MAX10 pin connection guidelines are clear about necessity of connecting all PLL supply pins. "Connect VCCD_PLL[1..4] pins to 1.2-V power supply even if the PLL is not used." They don't tell if partial functionality can be achieved without it. You may try if any PLL is still working.