PFD1_CLKGATE
reg |= PFD0_CLKGATE | PFD1_CLKGATE;
reg |= PFD0_CLKGATE | PFD1_CLKGATE | PFD2_CLKGATE;
reg |= PFD0_CLKGATE | PFD1_CLKGATE | PFD2_CLKGATE | PFD3_CLKGATE;