Why can't I pack two independent 18x18 multipliers into single Arria® V DSP block? - Why can't I pack two independent 18x18 multipliers into single Arria® V DSP block? Description Under certain conditions, the Quartus® II software may not be able to pack two independent 18x18 multipliers into the same Arria® V DSP Block. Resolution To work around this issue, add the following line into your quartus.ini file under the project directory: fsac_ff_enable_mac_scan_chain_packing=OFF If you do not already have a quartus.ini file, use the text editor and create this file in your project directory, then add the above line. This problem is fixed in Quartus® 13.1. Custom Fields values: ['novalue'] Troubleshooting 2205801022 True ['DSP Builder for Pro Edition IPT-DSPBUILDER'] ['FPGA Dev Tools Quartus II Software'] 13.1 12.0 ['Arria® V GT FPGA', 'Arria® V GX FPGA', 'Arria® V GZ FPGA', 'Arria® V ST FPGA', 'Arria® V SX FPGA', 'Stratix® V E FPGA', 'Stratix® V GS FPGA', 'Stratix® V GT FPGA', 'Stratix® V GX FPGA'] ['novalue'] ['novalue'] ['novalue']