irq.c

LPC2102的keil vendor code

/*****************************************************************************
 *   irq.c: Interrupt handler C file for Philips LPC214x Family Microprocessors
 *
 *   Copyright(C) 2006, Philips Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2005.10.01  ver 1.00    Prelimnary version, first Release
 *
******************************************************************************/
#include "LPC210x.h"			/* LPC23XX Peripheral Registers	*/
#include "type.h"
#include "irq.h"

/******************************************************************************
** Function name:	DefaultVICHandler
** Descriptions:	Default VIC interrupt handler.
**					This handler is set to deal with spurious interrupt.
**					If the IRQ service routine reads the VIC address register, 
**					and no IRQ slot responses as described above, this address
**					is returned.
** Parameters:		None
** Returned value:	None
******************************************************************************/
void DefaultVICHandler (void) __irq
{
    /* if the IRQ is not installed into the VIC, and interrupt occurs, the
    default interrupt VIC address will be used. This could happen in a race 
    condition. For debugging, use this endless loop to trace back. */
    /* For more details, see Philips appnote AN10414 */
    VICVectAddr = 0;		/* Acknowledge Interrupt */ 
    while ( 1 );
}

/* Initialize the interrupt controller */
/******************************************************************************
** Function name:	init_VIC
** Descriptions:	Initialize VIC interrupt controller.
** Parameters:		None
** Returned value:	None
******************************************************************************/
void init_VIC(void) 
{
    DWORD i = 0;
    DWORD *vect_addr, *vect_cntl;
   	
    /* initialize VIC*/
    VICIntEnClr = 0xffffffff;
    VICVectAddr = 0;
    VICIntSelect = 0;

    /* set all the vector and vector control register to 0 */
    for ( i = 0; i < VIC_SIZE; i++ )
    {
		vect_addr = (DWORD *)(VIC_BASE_ADDR + VECT_ADDR_INDEX + i*4);
		vect_cntl = (DWORD *)(VIC_BASE_ADDR + VECT_CNTL_INDEX + i*4);
		*vect_addr = 0;	
		*vect_cntl = 0;
    }

    /* Install the default VIC handler here */
    VICDefVectAddr = (DWORD)DefaultVICHandler;   
    return;
}

/******************************************************************************
** Function name:	install_irq
** Descriptions:	Install interrupt handler
**					The max VIC size is 16, but, there are 32 interrupt
**					request inputs. Not all of them can be installed into
**					VIC table at the same time.
**					The order of the interrupt request installation is
**					first come first serve.
** Parameters:		Interrupt number and interrupt handler address
** Returned value:	true or false, when the table is full, return false
******************************************************************************/
DWORD install_irq( DWORD IntNumber, void *HandlerAddr )
{
    DWORD i;
    DWORD *vect_addr;
    DWORD *vect_cntl;
      
    VICIntEnClr = 1 << IntNumber;	/* Disable Interrupt */
    
    for ( i = 0; i < VIC_SIZE; i++ )
    {
		/* find first un-assigned VIC address for the handler */
	
		vect_addr = (DWORD *)(VIC_BASE_ADDR + VECT_ADDR_INDEX + i*4);
		vect_cntl = (DWORD *)(VIC_BASE_ADDR + VECT_CNTL_INDEX + i*4);

		if ( *vect_addr == (DWORD)NULL )
		{
		    *vect_addr = (DWORD)HandlerAddr;	/* set interrupt vector */
		    *vect_cntl = (DWORD)(IRQ_SLOT_EN | IntNumber);
		    break;
		}
    }

    if ( i == VIC_SIZE )
    {
		return( FALSE );		/* fatal error, can't find empty vector slot */
    }

    VICIntEnable = 1 << IntNumber;	/* Enable Interrupt */
	
    return( TRUE );
}

/******************************************************************************
** Function name:	uninstall_irq
** Descriptions:	Uninstall interrupt handler
**					Find the interrupt handler installed in the VIC
**					based on the interrupt number, set the location
**					back to NULL to uninstall it.
** Parameters:		Interrupt number
** Returned value:	true or false, when the interrupt number is not found, 
**					return false
******************************************************************************/
DWORD uninstall_irq( DWORD IntNumber )
{
    DWORD i;
    DWORD *vect_addr;
    DWORD *vect_cntl;
      
    VICIntEnClr = 1 << IntNumber;	/* Disable Interrupt */
    
    for ( i = 0; i < VIC_SIZE; i++ )
    {
	/* find first un-assigned VIC address for the handler */
	vect_addr = (DWORD *)(VIC_BASE_ADDR + VECT_ADDR_INDEX + i*4);
	vect_cntl = (DWORD *)(VIC_BASE_ADDR + VECT_CNTL_INDEX + i*4);
	if ( (*vect_cntl & ~IRQ_SLOT_EN ) == IntNumber )
	{
	    *vect_addr = (DWORD)NULL;	/* clear the VIC entry in the VIC table */
	    *vect_cntl &= ~IRQ_SLOT_EN;	/* disable SLOT_EN bit */	
	    break;
	}
    }
    if ( i == VIC_SIZE )
    {
	return( FALSE );		/* fatal error, can't find interrupt number 
					in vector slot */
    }
    VICIntEnable = 1 << IntNumber;	/* Enable Interrupt */
    return( TRUE );
}

/******************************************************************************
**                            End Of File
******************************************************************************/