pit.h.svn-base

德国Erlangen大学教学操作系统源码。

#ifndef __PIT_include__
#define __PIT_include__

#include "machine/io_port.h"


class PIT
{
public:

	struct PIT_ports
	{
		enum
		{
			data10 = 0x40,
			data11 = 0x41,
			data12 = 0x42,
			cmd1 = 0x43,
			data20 = 0x48,
			data21 = 0x49,
			data22 = 0x4a,
			cmd2 = 0x4b
		};
	};

	struct PIT_Attrib
	{
		enum
		{
			timer0 = 0x0,
			timer1 = 0x40,
			timer2 = 0x80,

			latch = 0x0,
			low = 0x10,
			high = 0x20,
			low_high = 0x30,

			mode0 = 0x0,
			mode1 = 0x2,
			mode2 = 0x4,
			mode3 = 0x6,
			mode4 = 0x8,
			mode5 = 0xa,

			bin = 0x0,
			bcd = 0x1,
			
			freqence = 1193181,

			max_counter = 0xffff,
			max_interval = 54925
		};
	};


	PIT();
	PIT(int us);
	PIT(PIT &pit);
	virtual ~PIT();

	void interval(int us);
	int interval();
	int convert(int us) const;
	
private:
	IO_Port cmd_port;
	IO_Port data_port;
	int _interval;
};

#endif