main.c

mpc55**系列芯片的例程 包括SCI,SPI,TIMER,FIT,EDMA等几乎所有功能的实现

/* main.c - INTC in Hardware vector mode using C ISRs */
/* Copyright Freescale Semiconductor, Inc. 2007. All Rights Reserved */
/* Rev 0.1 Oct 1 2004 Steve Mihalik */
/* Rev 1.0 May 19,2006 S.M.- renamed SWirq7Ctr to SWirq4Ctr for consistency */
/* Rev 1.1 Aug 12 1006 SM - Made  i volatile (to get fewer Nexus msgs in loop)*/
/* Jul 17 2007 SM - Passed IVPR value from link file, used relevant names */
/*                  for MPC551x bit fields & registers, invoked SW interrupt*/ 
/*                  on even count eMIOS Ch 0 ISRs, changed timeout to 1 msec*/
/*                  and changed EMIOS_MCR[PRE] & EMIOS Chan 0 A Register values */                                                   
/* Notes:  */
/*  1. MMU not initialized; must be done by debug scripts or BAM */
/*  2. SRAM not initialized; must be done by debug scripts or in a crt0 type file */
/*  3. Cache is not used */

#include "mpc563m.h" /* Use proper include file such as mpc5510.h or mpc5554.h */

extern uint32_t __IVPR_VALUE; /* Interrupt Vector Prefix value from link file*/

  int emiosCh0Ctr = 0;  /* Counter for eMIOS channel 0 interrupts */
  int SWirq4Ctr = 0;    /* Counter for software interrupt 4 */
  
asm void initIrqVectors(void) {
  lis		r3, __IVPR_VALUE@h	   /* IVPR  value is passed from link file */ 
  ori       r3, r3, __IVPR_VALUE@l /* Note: IVPR lower bits are unused in MPC555x */
  mtivpr	r3									 
}

void initINTC(void) {	
/* Use one the following two lines */
/*INTC.MCR.B.HVEN_PRC0 = 1;*//* MPC551x: initialize Proc'r 0 for HW vector mosde */
  INTC.MCR.B.HVEN = 1;       /* MPC555x: initialize Proc'r 0 for HW vector mosde */
}

void initEMIOS(void) {
  EMIOS.MCR.B.GPRE= 11;		/* Divide sysclk by (11+1) for eMIOS clock */
  EMIOS.MCR.B.GPREN = 1;	/* Enable eMIOS clock */
  EMIOS.MCR.B.GTBE = 1;		/* Enable global time base */
  EMIOS.MCR.B.FRZ = 1;		/* Enable stopping channels when in debug mode */
/* Following for MPC551x only: */
/*EMIOS.UCDIS.R = 0;  */    /* Ensure all channels are enabled */
/* Use one of the following two lines: */
/*INTC.PSR[58].R = 1;  */          /* MPC551x: Raise eMIOS chan 0 IRQ priority = 1 */
  INTC.PSR[51].R = 1;              /* MPC555x: Raise eMIOS chan 0 IRQ priority = 1 */
  EMIOS.CH[0].CADR.R = 999;        /* Period will be 999+1=1000 channel clocks */
/* Use one of the next two lines:  MCB mode is not in all MPC555x devices */
  EMIOS.CH[0].CCR.B.MODE = 0x50;   /*  MPC551x or MPC563x: Mod. Counter Buffered (MCB) */
/*EMIOS.CH[0].CCR.B.MODE = 0x10;*/ /* MPC555x: Modulus Counter (MC), internal clock */
  EMIOS.CH[0].CCR.B.BSL = 0x3;	   /* Use internal counter */
  EMIOS.CH[0].CCR.B.UCPREN = 1;    /* Enable prescaler; uses default divide by 1 */
  EMIOS.CH[0].CCR.B.FREN = 1; 	   /* Stop (freeze) channel registers when in debug mode */
  EMIOS.CH[0].CCR.B.FEN=1;         /* Flag enables interrupt */
}

void initSwIrq4(void) {
  INTC.PSR[4].R = 2;		/* Software interrupt 4 IRQ priority = 2 */
}

void enableIrq(void) {
/* Use one of the following two lines to lower the INTC current priority */
/*INTC.CPR_PRC0.B.PRI = 0; */  /* MPC551x: Lower INTC's current priority */
  INTC.CPR.B.PRI = 0;	       /* MPC555x: Lower INTC's current priority */
   asm(" wrteei 1");           /* Enable external interrupts */
}

void main (void) {	
  vuint32_t i = 0;    /* Dummy idle counter */
  
  initIrqVectors();   /* Initialize exceptions: only need to load IVPR */
  initINTC();         /* Initialize INTC for hardware vector mode */
  initEMIOS();        /* Initialize eMIOS channel 0 for 1KHz IRQ, priority 2 */
  initSwIrq4();       /* Initialize software interrupt 4 */
  enableIrq();		  /* Ensure INTC current prority=0 & enable IRQ */

  while (1) { 
  	i++;
  }	
}

void emiosCh0ISR(void) {
  emiosCh0Ctr++;              /* Increment interrupt counter */
  if ((emiosCh0Ctr & 1)==0) { /* If emiosCh0Ctr is even*/
    INTC.SSCIR[4].R = 2;      /*  then nvoke software interrupt 4 */
  }
  EMIOS.CH[0].CSR.B.FLAG=1;   /* Clear channel's flag */ 
}

void SwIrq4ISR(void) {
  SWirq4Ctr++;              /* Increment interrupt counter */
  INTC.SSCIR[4].R = 1;      /* Clear channel's flag */  
}