Why can't I use the VHDL Unsigned data type in Qsys? - Why can't I use the VHDL Unsigned data type in Qsys? Description You cannot use VHDL Unsigned data type, because it is an unsupported data type in Qsys. Resolution Use only the Qsys VHDL data types described in "Parameters" section of the Component Interface Tcl Reference (pdf) manual. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['novalue'] novalue novalue ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']