t0.c

基于8515的lcd显示控制程序

//
//	File Name:		t0.c
//
//	Title:			Internal timer 0 implementation
//
//	Description:	
//
//	Creation Date:	2/6/00 5:31:06 PM
//
//	By:				A.C. Verbeck
//
//	This file is subject to the terms and conditions of the GNU General Public
//	License.  See the file COPYING in the main directory of this archive
//	for more details.
//

#include <io8515v.h>
#include <stdio.h>
#include <macros.h>

#include "Basetype.h"
#include "t0.h"

#pragma interrupt_handler	t0_isr:8;

//
//	Local defines
//
#define		MAX_CT		0xFF		//	Max count that can be assigned
#define		_1MS		0x3f		//	1.008mS delay time
#define		_2MS		0x7D		//	2mS delay time (exact)
#define		_4MS		0xFA		//	4mS delay time (exact)

//
//	Local data
//
UInt16	timer_ct	= 0;			//	Current timer count
UInt16	timer_set	= 0;			//	Timer time out value

//
//	Local functions
//
static void t0_isr(void);

//
//	Function Name:
//		T0_init
//
//	Description:
//		Initialize internal timer 0.
//		- set divider to ck/64
//		- set count to 63
//		- this gives a 1.008mS interrupt interval (992Hz)
//
//	Parameters:
//		(none)
//
//	Returns:
//		(nothing)
//
void T0_init(void)
{
	CLI();									//	Interrupts OFF
	TCCR0 = 0x03;							//	Set divider to ck/64
	TCNT0 = (MAX_CT-_1MS);					//	Set the time out
	TIMSK |= 0x02;							//	Enable the interrupt

	timer_ct = 0;							//	Init the soft timer
	SEI();									//	Interrupts ON
} 

void T0_clear(void)
{
	timer_ct = 0;
}


//
//	Function Name:
//		T0_set
//
//	Description:
//		Set the next timeout for the internal timer 0.
//		Note that this code works even if the timer
//		"rolls over".
//
//	Parameters:
//		UInt16	time_out - the wakeup time
//
//	Returns:
//		(nothing)
//
void T0_set(UInt16 time_out)
{
	CLI();									//	Interrupts OFF
	timer_ct  = 0;							//	Clear the timer count to 0
	timer_set = time_out;					//	Set the new timeout
	SEI();									//	Interrupts ON
}
UInt16 T0_get(void)
{
	return timer_ct;
}


void T0_enable(void)
{
	TIMSK |= 0x02;							//	Enable the interrupt
}
void T0_disable(void)
{
	TIMSK &= ~0x02;							//	Disable the interrupt
}

void T0_sleep(UInt16 time_out)
{
	CLI();									//	Interrupts OFF
	timer_ct  = 0;							//	Clear the timer count to 0
	timer_set = time_out;					//	Set the new timeout
	SEI();									//	Interrupts ON
	while (timer_ct != timer_set);			//	Just wait here
}

static void t0_isr(void)
{
	++timer_ct;								//	Boost the software timer
	TCNT0 = (MAX_CT-_1MS);					//	Set the time out
}

//
//	End of: t0.c
//