Why do I unexpectedly observe intermittent DDM Errors?
Description Beginning January 10, 2026, executing commands in the terminal or GUI of Quartus® Prime Pro Edition software, Quartus Embedded Edition software or select standalone tools may cause the software or tool to crash with an error similar to the crash signature shown below. This error affects: Quartus Prime Pro Software versions v23.3 through v25.3.1 Standalone Quartus Prime Pro Programmer v23.3 through v25.3.1 Standalone Quartus Prime Pro Embedded Edition v25.3 and v25.3.1 Standalone Quartus Prime Pro Power Thermal Analyzer v25.3 through v25.3.1 This issue is not observed in Quartus Prime Pro Edition versions 23.2 or prior or Quartus Prime Standard Edition. Crash Signature: Error (22912): Unhandled exception: Fatal Error: Assertion failed tools/cpp/ddm/ddm_assessor.cpp:53: DDM_T::verify_token(token) : Cannot identify the client from function assertion_error in tools/cpp/ddm_report/ddm_report_msg.cpp@465 *** Fatal Error: Program termination requested *** *** Below is the stack trace at the time the error occurred. *** The lines beginning "Err Handler" represent frames relating *** to generating this report. *** The point at which the error occurred is somewhere after these lines. *** There may be a few frames representing standard/library code *** before the Quartus frames begin. *** The search for the error should begin with the Quartus frames. *** Unwinder: libunwind *** Stack depth: 15 Quartus 0x24e67: err_terminator() + 0x1bc (ccl_err) Quartus 0xb036a: __cxxabiv1::__terminate(void (*)()) + 0xa (stdc++) Quartus 0xb03d5: (stdc++) Quartus 0xb0628: (stdc++) Quartus 0x1680d: void ddm_throw<DDM_RUNTIME_ERROR>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) + 0x26d (ddm_report) Quartus 0x13fae: DDM_REPORT::DDM_ASSERTION_HANDLER::assertion_error(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) const + 0xde (ddm_report) Quartus 0x12a52: DDM_REPORT::ASSERTION_HANDLER::error(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) + 0x72 (ddm_report) Quartus 0x13e64: DDM_REPORT::detail::assert_at_line(char const*, char const*, int, char const*, ...) + 0x1b4 (ddm_report) Quartus 0x205fb0: ddm_set_lassessor(DDM_T_ASSESSOR*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) + 0x60 (ddm) Quartus 0xf4445: DMS_MANAGER::DMS_MANAGER() + 0x5c5 (dni_dms) Quartus 0xf45b2: DMS_MANAGER::get() + 0x7a (dni_dms) Quartus 0xf6db4: _GLOBAL__sub_I_dms_manager.cpp + 0x58 (dni_dms) Quartus 0x647e: (ld-linux-x86-64) Quartus 0x6568: (ld-linux-x86-64) Quartus 0x202ca: (ld-linux-x86-64) Resolution To work around this problem: For Windows machines Download and unzip the Quartus Prime Pro version zip file that matches your Quartus Prime Pro version from this KDB. Double click on the executable ending in “windows.exe”. When the GUI pops up, press Next. Note that the GUI may look slightly different depending on the version of Quartus you are using. Accept the license agreement Specify the directory where the patch needs to be applied which may be a different location than Quartus install if you have standalone tools in a different directory from your Quartus Prime Pro software installation. Keep “Allow Patch to be uninstalled” selected. Select the software in which to install the patch: The patch will install in the directory of the software or tool you have selected. You will see an uninstall directory for the patch in your software or tool folder where patch is installed; it will contain an executable to uninstall the patch if required for any reason. To confirm patch is installed, you can run quartus_sh -v or corresponding version command for your tool via command line. Alternatively, you can Open Quartus in the GUI and select Help → About Quartus Prime in the main menu. If you are opening up a standalone tool you will navigate to Help-> About <tool_name>. For the Command Line Implementation of the patch in Windows, use the following command: <patch_filename.exe> --mode unattended --installdir <your_install_directory> --accept_eula 1 --patch_to [quartus|qprogrammer|qemb|pta] # An example to patch Quartus Prime Pro Edition Software v25.3: quartus-25.3-0.27-windows.exe --mode unattended --installdir /tmp/altera_pro/25.3 --accept_eula 1 # An example to patch the Standalone Programmer for Quartus Prime Pro Software v25.3: quartus-25.3-0.27-windows.exe --mode unattended --installdir /tmp/altera_pro/25.3 --accept_eula 1 --patch_to qprogrammer For Linux machines: Download and unzip the Quartus Prime Pro version zip file that matches your Quartus Prime Pro version from this KDB. Ensure you run chmod +x on the file ending with linux.run. Run in the command line: ./<installation_patch_run_file>. When GUI pops up, press Next. Note that the GUI may look slightly different depending on the version of Quartus you are using. Accept the license agreement Specify the directory where the patch needs to be applied which may be a different location than Quartus install if you have standalone tools in a different directory from your Quartus Prime Pro software installation. Keep “Allow Patch to be uninstalled” selected. Select the software in which to install the patch: The patch will install in the directory of the software or tool you have selected. You will see an uninstall directory for the patch in your software or tool folder where patch installed; it will contain an executable to uninstall the patch if required for any reason. To confirm patch is installed, you can run ./quartus_sh -v or corresponding version command for your tool via command line. Alternatively, you can Open Quartus in the GUI and select Help → About Quartus Prime in the main menu. If you are opening up a standalone tool you will navigate to Help-> About <tool_name>. For the Command Line Implementation of the patch in Linux, use the following command: ./<patch_filename.run> --mode unattended --installdir <your_install_directory> --accept_eula 1 --patch_to [quartus|qprogrammer|qemb|pta] # An example to patch Quartus Prime Pro Edition v25.3: ./quartus-25.3-0.27-linux.run --mode unattended --installdir /tmp/altera_pro/25.3 --accept_eula 1 # An example to patch the Standalone Programmer for Quartus Prime Pro Software v25.3: ./quartus-25.3-0.27-linux.run --mode unattended --installdir /tmp/altera_pro/25.3 --accept_eula 1 --patch_to qprogrammer This problem has been fixed in Quartus® Prime Pro Edition Software version 26.1. The below table lists the patches that are available and the associated patch number. The patch zip files are attached to the KDB below: Quartus Prime Pro Edition Version Patch Number 23.3 0.52 23.4 0.70 23.4.1 1.01 24.1 0.52 24.2 0.64 24.3 0.35 24.3.1 1.29 25.1 0.36 25.1.1 1.31 25.3 0.27 25.3.1 1.02Why does my Quartus® Prime Installation fail with certificate error: SSL certificate problem: unable to get local issuer certificate (curlcode 60)?
Description Due to a problem in the Quartus® Prime Installer Software, you might see the error message shown below when you click Download & Install. This happens because the certificate bundled with the Quartus® Prime Installer Software is no longer accepted by the Altera® Content Delivery Network (CDN). As a result, secure downloads initiated during the installation process cannot be verified using the outdated certificate. The issue impacts the Installer for the following versions of Quartus software: Operating System Quartus Prime Pro Installer Version(s) Quartus Std/Lite Installer Version(s) Microsoft Windows* 23.3 to 25.3.1 23.1std to 25.1std Linux* 23.3 to 23.4 23.1std The KDB workaround provided below applies to the following versions of Quartus software: Quartus Prime Pro Installer Version(s) Quartus Std/Lite Installer Version(s) KDB workaround applies to 24.3 to 25.3.1 24.1std to 25.1std Note that for all other affected versions not covered by the KDB, you cannot use the installer workaround and must download Quartus software package files individually without using the installer. Separate packages can be found in the Individual Files tab of the Quartus Software Download pages. Resolution To work around this problem, follow these steps: 1. Download and unzip the cacert.zip, which contains the cacert.pem certificate file. 2. Specify the new certificate using one of the following methods: i) Command Line Interface (CLI): Open a command prompt or terminal and run the installer with the--cacert option, pointing to the new certificate file. Windows*: qinst_<version>.exe -sp"--cacert <full path to cacert.pem>" Linux*: qinst_<version>.run -- --cacert <full path to cacert.pem> ii) Graphical User Interface (GUI): - Open the Quartus® Prime Installer, navigate to Settings, locate the CA Certificate Path, and specify the full path to the cacert.pem certificate file. - Then, click Apply > OK. This problem is scheduled to be resolved in a future release of the Quartus® Prime Installer Software.
Why don’t I get a programming file when I compile with the Quartus® Prime Pro Edition software version 25.1.1?
Description Beginning with version 25.1.1 of the Quartus® Prime Pro Edition software, pin location assignments and I/O standard assignments are required for a programming file to be generated. If these required assignments are missing, no programming file is generated. You must add the required assignments and recompile your design to generate a programming file. If you do not want to generate a programming file, you may ignore this behavior change. To determine whether your design is missing pin location or I/O standard assignments, review your compilation messages. If either of the following messages was generated during your compile, your design is missing pin location or I/O standard assignments that are required to generate a programming file: Critical Warning: Some pins have incomplete I/O assignments. Refer to the I/O Assignment Warnings report for details Critical Warning: No exact pin location assignment(s) for <number> pins of <number> total pins. For the list of pins, please refer to the I/O Assignment Warnings table in the fitter report Resolution Review the I/O Assignment Warnings report, found in the Place sub-section of the Fitter section of the compilation report. Alternately, review the <revision>.fit.plan.rpt report file. For any pins in the I/O Assignment Warnings report that are reported as “Missing location assignment” or “Missing I/O standard,” add the appropriate location or I/O standard assignment. For help making these assignments, refer to Assigning I/O Pins After adding any required assignments, recompile the design to generate a programming file. This change applies to all device families supported by the Quartus® Prime Pro Edition software, beginning in version 25.1.1. Missing pin location or I/O standard assignments are reported as a critical warning, not an error. If you script the compilation of projects, the exit code of the compilation process still indicates success even if pin location or I/O standard assignments are missing, because missing pin location or I/O assignments are reported as a critical warning, not an error.How do I constrain my clock domain crossing?
Description It is essential to apply timing constraints to your multibit clock domain crossing. If this bus has a set_false_path constraint, then the skew across the bus can be more than 1 clock period, which can cause functional errors. The first requirement is that you do not have a set_false_path constraint between the two clock domains. If you don't want paths between them to be analyzed for setup and hold, then you can use set_clock_groups, which has a lower precedence. Next, constrain the paths with set_net_delay to make them as short as possible and with set_max_skew. set_max_skew does not constrain the fitter, but you can analyse against this constraint in the Timing Analyzer. Resolution The constraints for a clock domain crossing between data_a in clock domain clk_a and data_b in clock domain clk_b might look like this. create_clock -name clk_a -period 4.000 [get_ports {clk_a}] create_clock -name clk_b -period 4.500 [get_ports {clk_b}] set_clock_groups -asynchronous -group [get_clocks {clk_a}] -group [get_clocks {clk_b}] set_net_delay -from [get_registers {data_a[*]}] -to [get_registers {data_b[*]}] -max -get_value_from_clock_period dst_clock_period -value_multiplier 0.8 set_max_skew -from [get_keepers {data_a[*]}] -to [get_keepers {data_b[*]}] -get_skew_value_from_clock_period min_clock_period -skew_value_multiplier 0.8 The skew requirements will depend on your design and how you handled the clock domain crossing. Finally, check the timing of your clock domain crossing by running Report Max Skew Summary and Report Net Delay Summary in the Timing Analyzer.What timing constraints do I need to apply to the automatically generated altera_reserved_* JTAG pins in my design?
Description Many in-system debugging tools, such as the Signal Tap Logic Analyzer, the In-System Sources and Probes, or the Nios® II debugger, use the JTAG interface in Altera® FPGAs. The Quartus® Prime Software automatically generates the altera_reserved_tck, altera_reserved_tms, altera_reserved_tdi, and altera_reserved_tdo pins for a design that uses a JTAG accessible module. Because of this, the Timing Analyzer flags these signals as unconstrained when an unconstrained path report is generated. Resolution You can constrain the JTAG signals by applying the SDC commands of the JTAG Signal Constraints template. In the Quartus® Prime GUI, go to File > New > Synopsys Design Constraints File. Then, in the Text Editor, click on Insert Template and then select Timing Analyzer > SDC Cookbook > JTAG Signal Constraints. Customize the constraints in the template as needed, where indicated. Save the new SDC file, add it to your project, and compile.Why does the Nios® V processor that applies fast JTAG UART driver stop (stuck in a loop) when the JTAG UART terminal is not active?
Description Due to a problem in the Board Support Package Editor of Quartus ® Prime software, the JTAG UART driver for fast implementation might get stuck in a loop for any Nios ® V processor designs, when JTAG UART terminal is not active. This problem has been present since: Quartus ® Prime Pro Edition software version 21.3 Quartus ® Prime Standard Edition software version 22.1 It is because the JTAG UART IP is initialized before the Nios ® V processor initialization in alt_sys_init.c. For example: void alt_sys_init( void ) { ALTERA_AVALON_JTAG_UART_INIT (JTAG_UART, jtag_uart); INTEL_NIOSV_M_INIT (NIOS, nios); } Resolution To work around this problem, update the alt_sys_init.c to initialize the Nios ® V processor first. void alt_sys_init( void ) { INTEL_NIOSV_M_INIT (NIOS, nios); ALTERA_AVALON_JTAG_UART_INIT (JTAG_UART, jtag_uart); } This problem is currently scheduled to be resolved in a future release of the Quartus ® Prime software. Additional Information Refer to Embedded Peripherals IP User Guide [titled as JTAG UART Core - Driver Options: Fast vs. Small Implementations] for more information about the JTAG UART driver for fast (non-blocking) and slow (blocking) implementation. Related Article NIOSV firmware stuck when juart-terminal is not open for the print messages.Why does the ASMI Parallel II IP or the Generic Quad SPI Controller II IP fail to access a QSPI flash memory device?
Description Due to a problem in multiple Quartus® Prime Pro Edition and Standard Edition software versions, the ASMI Parallel II IP or the Generic Quad SPI Controller II IP fails to access a Quad SPI flash memory device. The affected software versions are: Quartus® Prime Pro Edition software versions from 22.1 to 25.3 Quartus® Prime Standard Edition software versions from 22.1 to 24.1 Chronologically, Prior to version 22.1, the initial state of DATA[3:2] was high. For the affected software versions, the initial state of DATA[3:2] was incorrectly changed to Hi-Z. For reader’s information, some quad SPI flash memory devices support RESET or HOLD function on DATA[3] and WRITE_PROTECT function on DATA[2]. DATA pins can be known as DATA, DQ, IO, or SIO across different QSPI flash memory device vendors. This modification to Hi-Z is recognized as low, thus the active-low RESET, HOLD and WRITE_PROTECT functions are enabled. With these, they prevent the flash controller IP from gaining access to flash devices. Resolution DATA[3:2] must be kept high as the initial state. If the targeted flash device is the Active Serial configuration flash memory, this problem is fixed starting from, Quartus® Prime Pro Edition software version 25.3.1, and Quartus® Prime Standard Edition software version 25.1. Otherwise (i.e. generic-purpose flash memory or affected software version), please refer to the workarounds below. For affected software versions, Targeted Flash Device Workarounds Active Serial configuration flash memory Differentiated with: DATA[3:2] pins are assigned to dedicated AS_DATA[3:2] pins Disable dedicated Active Serial interface option is turned off The initial state of DATA[3:2] is Hi-Z. Add external pull-up registers to the I/O VCC voltage on DATA[3:2]. Internal weak pull-up resistor option is unavailable for dedicated AS_DATA pins. Generic-purpose flash memory Differentiated with: DATA[3:2] pins are assigned to generic I/O pins Disable dedicated Active Serial interface option is turned on The initial state of DATA[3:2] is Hi-Z. Add external pull-up registers to the I/O VCC voltage on DATA[3:2], or Enable internal weak pull-up resistor on DATA[3:2] pins in Quartus® design project After Quartus® Prime Pro Edition software version 25.3.1 and Quartus® Prime Standard Edition software version 25.1, Targeted Flash Device Workarounds Active Serial configuration flash memory Differentiated with: DATA[3:2] pins are assigned to dedicated AS_DATA[3:2] pins Disable dedicated Active Serial interface option is turned off The initial state of DATA[3:2] is reverted to high. No workaround is needed. Generic-purpose flash memory Differentiated with: DATA[3:2] pins are assigned to generic I/O pins Disable dedicated Active Serial interface option is turned on The initial state of DATA[3:2] is Hi-Z. Add external pull-up registers to the I/O VCC voltage on DATA[3:2], or Enable internal weak pull-up resistor on DATA[3:2] pins in Quartus® design project Related IP Cores ASMI Parallel II IP, Generic Quad SPI Controller II IPWhy doesn't the Triple-Speed Ethernet (TSE) FPGA IP for all devices always maintain a negative running disparity during idle cycles as per the IEEE 802.3 standard?
Description Due to a problem in the Quartus® Prime Pro Edition software, when using the Triple-Speed Ethernet (TSE) FPGA IP across supported device families, the transmitter may not maintain a negative running disparity during idle cycles as defined in the IEEE 802.3 standard. Specifically, the first IDLE sequence after a packet or configuration set is not always generated as /I1/, which is required to restore the running disparity to negative. Resolution A patch is available to fix this problem for the Quartus® Prime Pro Edition software version 24.1 for Agilex™ 7 FPGA F-Series E-Tile devices. Download version 24.1 patch 0.47 for Windows and Linux below This patch ensures the transmitter maintains negative running disparity for Agilex™ 7 FPGA F-Series E-Tile devices by inserting the first idle sequence (/I1/) whenever required, followed by all subsequent idle sequences (/I2/), maintaining compliance with the IEEE 802.3 standard. Please contact your local Sales representative or submit a request through the Support page for further support. This problem is scheduled to be fixed in a future release of the Quartus Prime Pro Edition software.Why does niosv-stack-report return error during Nios® V build flow in RiscFree* IDE for Intel® FPGAs?
Description Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 22.2, this problem may be seen in RiscFree* IDE for Intel® FPGAs when building the Nios® V processor software. The error descriptions are shown as followed make: *** [Makefile:91: all] Error 2 make[1]: *** [CMakeFiles/Makefile2:156: CMakeFiles/niosv-stack-report.dir/all] Error 2 make[1]: *** Waiting for unfinished jobs.... make[2]: *** [CMakeFiles/niosv-stack-report.dir/build.make:73: app.elf.stack_report] Error 127 The niosv-stack-report utility is only present in Intel® Quartus® Prime Pro Edition Software. The error message above would occur when building the application if, RiscFree* IDE for Intel® FPGAs is installed as a standalone development tool with the Intel® Quartus® Prime Programmer RiscFree* IDE for Intel® FPGAs is not launched from the Nios® V Command Shell Resolution To work around this problem in the Intel® Quartus® Prime Pro Edition Software version 22.2, do these in any order: You may ignore this error and proceed as usual. The necessary software build files (such as .elf file and .objcopy file) will be created and are not affected by this error Launch the RiscFree* IDE for Intel® FPGAs from the Nios® V Command Shell This problem is fixed starting with the Intel® Quartus® Prime Pro Edition Software version 22.3.Why does the RTL Viewer shows 'The RTL netlist is not available. Run Analysis and Elaboration to view RTL netlist'?
Description When choosing the Aggressive Compile Time optimization mode in the Quartus® Prime Pro Edition Software version 19.1 or later, this message may be seen when opening the RTL Viewer after a successful compilation process. When selecting the Aggressive Compile Time optimization mode, the Quartus® Prime Pro Edition Software does not generate a full synthesis netlist to reduce the compilation time. Without a full synthesis netlist, the RTL Viewer cannot elaborate a browsable RTL diagram. Resolution To work around this problem, select a different optimization mode in the Quartus® Prime Pro Edition Software and recompile the design.
