cpu.c
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/*
* Copyright (C) 2013, Freie Universitaet Berlin (FUB). All rights reserved.
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup lpc2387
* @{
*/
#include <stdint.h>
#include "cpu.h"
#include "irq.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)(void), int Priority)
{
VICIntEnClr = 1 << IntNumber; /* Disable Interrupt */
if (IntNumber >= VIC_SIZE) {
return (false);
}
else {
/* find first un-assigned VIC address for the handler */
int *vect_addr = (int *)(VIC_BASE_ADDR + VECT_ADDR_INDEX + IntNumber * 4);
int *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);
}
}
__attribute__((naked,noreturn)) void arm_reset(void)
{
irq_disable();
WDTC = 0x0FFFF;
WDMOD = 0x03;
WDFEED= 0xAA;
WDFEED= 0x55;
while(1) {}
}
/** @} */