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 - Software vector mode program using C isr */
/* Jan 15, 2004 S.Mihalik -- Copyright Freescale, 2004. All Rights Reserved */
/* Feb 9, 2004 S.M. - removed unused cache init & enabled eMIOS FREEZE */
/* Mar 4, 2004 S.M. - added software interrupt 7 code */
/* May 19,2006 S.M.- renamed SWirq7Ctr to SWirq4Ctr for consistency */
/* Aug 12 2006 S.M. - made i volatile (to get fewer Nexus messages 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 */                                       
/* Copyright Freescale Semiconductor, In.c 2007 All rights reserved. */
/* 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 like mpc5510.h or mpc5554.h */

extern IVOR4Handler();
extern uint32_t __IVPR_VALUE; /* Interrupt Vector Prefix value from link file*/
extern const vuint32_t IntcIsrVectorTable[];

  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 
  mtivpr   r3									 
/* The following two lines are required for MPC555x, and are not used for MPC551x*/
  li	  	r3, IVOR4Handler@l 	/* IVOR4 = lower half of handler address */							
  mtivor4	r3	 					
}

void initINTC(void) {	
/* Use the first 3 or next 3 lines for MPC551x or MPC555x: */
/* INTC.MCR.B.HVEN_PRC0 = 0;*/   /* MPC551x Proc'r 0: initialize for SW vector mode */
/* INTC.MCR.B.VTES_PRC0 = 0;  */ /* MPC551x Proc'r 0: default vector table 4B offsets */
/* INTC.IACKR_PRC0.R = (uint32_t) &IntcIsrVectorTable[0]; */   /* MPC551x: ISR table base */
  INTC.MCR.B.HVEN = 0;           /* MPC555x: initialize for SW vector mode */
  INTC.MCR.B.VTES = 0;           /* MPC555x: Use default vector table 4B offsets */
  INTC.IACKR.R = (uint32_t) &IntcIsrVectorTable[0]; /* MPC555x: INTC ISR table base */
}

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 Proc'r 0: 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 software 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 */  
}