Clock Domains and Clock Domain Crossing (CDC)
The FPGA design uses two clock domains: 100 MHz and 40 MHz. Clock domain crossing (CDC) between these domains is handled as follows: Data transfer (100 MHz → 40 MHz): A FIFO is used to provide reliable synchronization and maintain data integrity during transfers from the faster to the slower clock domain. Control signals (100 MHz ↔ 40 MHz): Shift-register synchronizers are used to safely transfer control signals in both directions between the two domains. The CDC implementation follows the recommendations outlined in the Altera Clock Domain Crossing tutorial. The main question concerns how timing constraints are applied: 1-Do the set_max_skew and set_data_delay constraints have any impact after defining the following asynchronous clock-group constraint? set_clock_groups -asynchronous -group {clkA} -group {clkB} 2-Additionally, how should the multiplier values (e.g., 0.8 or 0.9) used in set_max_skew and set_data_delay be determined or selected? Thanks.
USB blaster not detected in Quartus 24.1
Hi, Recently updated from windows 10 to windows 11. Previously was using Quartus 19.1 and after upgrade USB blaster driver got corrupted. Below are the steps I did to debug the issue: Update driver via enforce driver disable in windows. Load usb blaster driver of quartus 24.1 Uninstall quartus 19.1 and USB blaster drivers. Installed Quartus 24.1 and USB blaster driver that came with it. Even after step 3, same issue. How can I solve it? Even though Quartus 24.1 USB blaster is supported in windows 11. Device Manager Error reporting when USB blaster is connected. Signal Tap doesn't recognize any hardware connected.
Problem ALTPLL MegaWizzard in 25.1
Hello to all, today, I upgraded Quartus to version 25.1 (Lite Edition). Afterwards, I tried to upgrade the IP components. When starting MegaWizard ALTPLL, a confused dialog box appears. (see attached screenshot) It's not possible to use it at all. When I start MegaWizard for the second time, the error message “Failed to launch MegaWizard Plug-In Manager: ALTPLL” appears. My environment: - Quartus Prime version 25.1std.0 Build 1129 10/21/2025 SC Lite Edition - Windows 11 Pro version 25H2 Is there a way to fix this? Thank you in advance. Helmut
How to upgrade IP from Quartus 24.1 and add it to a Quartus 25.1 Project?
Hello ALTERA Quarts Experts, I have created and configured an ALT_PLL IP in Quartus Standard edition 24.1. Now i need to add that IP to a Quartus 25.1 Standard Edition project. I have tried this so far: added the IPs output files to my 25.1 project: readout_pll.qip, readout_pll.v, readout_pll_bb.v There is also a file called: readout_pll.ppf which appears to be an xml file. Not exactly sure what this is meant to do or if i also needed to add that? I then see the message from Quartus 25.1 asking me to do an auto IP upgrade, which id did and it was successful according to Quartus. But then i don't see the IP appear in the projects IP Catalogue even after i do an IP library refresh. Can anybody please tell me what else i need to do in order to be able to use the IP in my 25.1 Project ? I am having to do all this because the ALT_PLL symbol is all messed up and is unusable in Quartus Standard Edition 25.1. For That problem i have already created another post recently and have been assured this will be fixed. But for now until its fixed i need to do this IP upgrade. Thanks, Barry
Quartus Pro 25.3 Not showing HPS IO in Pin Planner
Hello, I have an Agilex-5 SoC design where the HPS IO pins I’ve assigned (UART, I2C, SD/MMC, etc.) are not appearing in the All Pins view in the Pin Planner, even with the filter set to “Pins: All.” Is this expected behavior, or is there another filter or setting I should adjust to view the HPS IO pins in the Pin Planner? Thank you, Dan
Quartus GUI License Error
Hi, I have been getting the below licence error when simulating / opening Quartus. I have checked my license, it's set up on my HP laptop in the environmental conditions, License set up in Questa and re-generated a license but I can't seem to find a route cause or a solution. Is anyone able to help?
