def METHOD_NAME(self, fragment):
    AlteraPlatform.METHOD_NAME(self, fragment)
    self.add_period_constraint(self.lookup_request("clk12", loose=True), 1e9/12e6)
    # Generate PLL clock in STA
    self.toolchain.additional_sdc_commands.append("derive_pll_clocks")
    # Calculates clock uncertainties
    self.toolchain.additional_sdc_commands.append("derive_clock_uncertainty")