AHDL Function Prototype (port name and order also apply to Verilog HDL)
The following AHDL function prototype is located in the AHDL Include File (.inc) Definitionaltufm_osc.inc in the <Quartus® Prime installation directory>\libraries\megafunctions directory.
FUNCTION altufm_osc ( oscena ) WITH ( OSC_FREQUENCY ) RETURNS ( osc );