occs.c

来自「MC56F802BLDC 可以使用的算法 就是电机启动有点慢」· C语言 代码 · 共 98 行

/*******************************************************************************
*
*  Motorola Inc.
*  (c) Copyright 2000 Motorola Inc.
*  ALL RIGHTS RESERVED.
*
********************************************************************************
*
*
*  File Name:   occs.c
*
*  Description: Source file for On-chip Clock Synthesis (OCCS) driver.
*
*
*  Modules Included:
*
*  Notes:
*
*
*******************************************************************************/
#include "appconfig.h"
#include "types.h"
#include "periph.h"
#include "arch.h"
#include "occs.h"


#ifdef __cplusplus
extern "C" {
#endif



void occsInit(void)
{
	#ifdef OCCS_CLKO_SELECT_REG
		/* Set CLKO Select Register */
		periphMemWrite(OCCS_CLKO_SELECT_REG, &ArchIO.Pll.SelectReg);
	#endif
	#ifdef OCCS_CONTROL_REG
		/* Enable Lock Detector, Set ZCLOCK Source to Prescaler, 
		   Let bit PRECS (Prescaler Clock Select) be as is */
		if ((OCCS_CONTROL_REG & 0x0003) == OCCS_ZCLOCK_POSTSCALER)
		{
			periphMemWrite((OCCS_CONTROL_REG & OCCS_PRESCALER_CLOCK_SELECT) | 
							OCCS_LOCK_DETECTOR_BIT | OCCS_ZCLOCK_PRESCALER,
						   &ArchIO.Pll.ControlReg);
		}
	#endif
	#ifdef OCCS_INTERNAL_OSC_REG
		/* Set Internal Oscillator Control Register. Only for 801. */
		 periphMemWrite(OCCS_INTERNAL_OSC_REG, &ArchIO.Pll.InternalOscReg);
	#endif
	#ifdef OCCS_DIVIDE_BY_REG
		/* Set Divide-by register */
		periphMemWrite(OCCS_DIVIDE_BY_REG, &ArchIO.Pll.DivideReg);
	#endif
	#ifdef OCCS_CONTROL_REG
		if ((OCCS_CONTROL_REG & 0x0003) == OCCS_ZCLOCK_POSTSCALER)
		{
			/* Wait until PLL is locked */
			while (!periphBitTest(OCCS_STATUS_LOCK_1, &ArchIO.Pll.StatusReg))
				;
		}
		/* ZCLOCK Source to Postscaler */
		periphMemWrite(OCCS_CONTROL_REG, &ArchIO.Pll.ControlReg);
	#endif
}



UInt32 occsGetIPBusFreq(UInt32 OscFreq)
{
	UWord16 DivBy,
			Prescaler,
	        Postscaler;

	DivBy = periphMemRead(&ArchIO.Pll.DivideReg);
	Prescaler = DivBy>>8;
	Postscaler = Prescaler>>2;
	DivBy &= 0x007F;
	Prescaler &= 0x0003;
	Postscaler &= 0x0003;
	if (periphBitTest(0x0001, &ArchIO.Pll.ControlReg))
	{ /* Prescaler Output */
		return (OscFreq>>++Prescaler);
	}
	if (periphBitTest(0x0002, &ArchIO.Pll.ControlReg))
	{ /* Postscaler Output */
		return ((OscFreq * ++DivBy)>>(++Prescaler + ++Postscaler));
	}
}



#ifdef __cplusplus
}
#endif