gistfile1.txt

bool setClock(ClockScheme clock) {
	switch (clock) {
		case Internal2Mhz : {
			OSC.CTRL |= b00001;  								// Bit 0 – RC2MEN: 2MHz Internal Oscillator Enable
			while((OSC.STATUS & b00001) == 0) { }				// Wait oscillator to stabilize

			uint8_t psctrl = b00000 << 2 | b00 << 0;			// No System Clock prescalers, protected by CCP! 
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.PSCTRL = psctrl;
			if (CLK.PSCTRL != psctrl) return false;				// Failed?

			uint8_t ctrl = b000;								// Select 2MHz internal oscillator to System Clock			 	
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.CTRL = ctrl;
			if (CLK.CTRL != ctrl) return false;					// Failed?
		
		} break;
		
		case Internal32Mhz : {
			OSC.CTRL |= b00010;  								// Bit 1 – RC32MEN: 32MHz Internal Oscillator Enable
			while((OSC.STATUS & b00010) == 0) { }				// Wait oscillator to stabilize

			uint8_t psctrl = b00000 << 2 | b00 << 0;			// No System Clock prescalers, protected by CCP! 
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.PSCTRL = psctrl;
			if (CLK.PSCTRL != psctrl) return false;				// Failed?
	
			uint8_t ctrl = b001;								// Select 32MHz internal oscillator to System Clock
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.CTRL = ctrl;
			if (CLK.CTRL != ctrl) return false;					// Failed?
		
		} break;

		case Internal32768hz : {
			OSC.CTRL |= b00100;  								// Bit 2 – RC32KEN: 32.768kHz Internal Oscillator Enable
			while((OSC.STATUS & b00100) == 0) { }				// Wait oscillator to stabilize

			uint8_t psctrl = b00000 << 2 | b00 << 0;			// No System Clock prescalers, protected by CCP! 
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.PSCTRL = psctrl;
			if (CLK.PSCTRL != psctrl) return false;				// Failed?
	
			uint8_t ctrl = b010;								// Select 32.768kHz internal oscillator to System Clock
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.CTRL = ctrl;
			if (CLK.CTRL != ctrl) return false;					// Failed?

		
		} break;
	
		case External32768hz : {
			OSC.XOSCCTRL = b00 << 6 | b1 << 5 | b0010;  		// Enable 32768Hz TOSC in Low Power Mode with 16K CLK start-up time

			OSC.CTRL |= b01000;  								// Enable External Oscillator
			while((OSC.STATUS & b01000) == 0) { }				// Wait External Oscillator to stabilize

			uint8_t psctrl = b00000 << 2 | b00 << 0;			// No System Clock prescalers, protected by CCP! 
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.PSCTRL = psctrl;
			if (CLK.PSCTRL != psctrl) return false;				// Failed?
	
			uint8_t ctrl = b011;								// Select external oscillator to System Clock			
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.CTRL = ctrl;
			if (CLK.CTRL != ctrl) return false;					// Failed?
			
		} break;

		case External16x2Mhz : {
			OSC.XOSCCTRL = b11 << 6 | b1011;  					// Enable 16MHz XTAL with 16K CLK start-up time
	
			OSC.CTRL |= b01000;  								// Enable External Oscillator
			while((OSC.STATUS & b01000) == 0) { }				// Wait External Oscillator to stabilize

			OSC.PLLCTRL = b11 << 6 | b00010;  					// Select External clock source with 2x PLL
			OSC.CTRL |= b10000;    								// Enable PLL
			while((OSC.STATUS & b10000) == 0) { }				// Wait PLL to stabilize

			uint8_t psctrl = b00000 << 2 | b00 << 0;			// No System Clock prescalers, protected by CCP! 
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.PSCTRL = psctrl;
			if (CLK.PSCTRL != psctrl) return false;				// Failed?
	
			uint8_t ctrl = b100;								// Select PLL to System Clock
			CCP = 0xD8; 										// Unlock Configuration Change Protection
			CLK.CTRL = ctrl;
			if (CLK.CTRL != ctrl) return false;					// Failed?
			
		} break;
		
	}
	
	return true;
}