RIOT/cpu/lpc2387/cpu.c

/******************************************************************************
Copyright (C) 2013, Freie Universitaet Berlin (FUB). All rights reserved.

These sources were developed at the Freie Universitaet Berlin, Computer Systems
and Telematics group (http://cst.mi.fu-berlin.de).
-------------------------------------------------------------------------------
This file is part of RIOT.

This file subject to the terms and conditions of the GNU Lesser General Public
License. See the file LICENSE in the top level directory for more details.
*******************************************************************************/

/**
 * @ingroup		lpc2387
 * @{
 */

#include "cpu.h"
#include <stdint.h>
#include "VIC.h"

void lpc2387_pclk_scale(uint32_t source, uint32_t target, uint32_t *pclksel, uint32_t *prescale)
{
    uint32_t pclkdiv;
    *prescale = source / target;

    if ((*prescale % 16) == 0) {
        *pclksel = 3;
        pclkdiv = 8;
    }
    else if ((*prescale % 8) == 0) {
        *pclksel = 0;
        pclkdiv = 4;
    }
    else if ((*prescale % 4) == 0) {
        *pclksel = 2;
        pclkdiv = 2;
    }
    else {
        *pclksel = 1;
        pclkdiv = 1;
    }

    *prescale /= pclkdiv;

    if (*prescale % 2) {
        (*prescale)++;
    }
}

void cpu_clock_scale(uint32_t source, uint32_t target, uint32_t *prescale)
{
    uint32_t pclksel;

    lpc2387_pclk_scale(source, target, &pclksel, prescale);

    PCLKSEL0 = (PCLKSEL0 & ~(BIT2 | BIT3)) | (pclksel << 2); 		// timer 0
    PCLKSEL0 = (PCLKSEL0 & ~(BIT4 | BIT5)) | (pclksel << 4); 		// timer 1
    PCLKSEL1 = (PCLKSEL1 & ~(BIT12 | BIT13)) | (pclksel << 12);	// timer 2
}

/******************************************************************************
** Function name:		install_irq
**
** Descriptions:		Install interrupt handler
** parameters:			Interrupt number, interrupt handler address,
**						interrupt priority
** Returned value:		true or false, return false if IntNum is out of range
**
******************************************************************************/
#define VIC_BASE_ADDR   0xFFFFF000

bool install_irq(int IntNumber, void *HandlerAddr, int Priority)
{
    int *vect_addr;
    int *vect_cntl;

    VICIntEnClr = 1 << IntNumber;	/* Disable Interrupt */

    if (IntNumber >= VIC_SIZE) {
        return (false);
    }
    else {
        /* find first un-assigned VIC address for the handler */
        vect_addr = (int *)(VIC_BASE_ADDR + VECT_ADDR_INDEX + IntNumber * 4);
        vect_cntl = (int *)(VIC_BASE_ADDR + VECT_CNTL_INDEX + IntNumber * 4);
        *vect_addr = (int)HandlerAddr;	/* set interrupt vector */
        *vect_cntl = Priority;
        VICIntEnable = 1 << IntNumber;	/* Enable Interrupt */
        return(true);
    }
}

/** @} */