cpu.c
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/*
* Copyright (C) 2015 Rakendra Thapa <rakendrathapa@gmail.com
*
* 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 cpu_lm4f120
* @{
*
* @file cpu.c
* @brief Implementation of the CPU initialization
*
* @author Rakendra Thapa <rakendrathapa@gmail.com>
* @}
*/
#include "cpu.h"
#include "irq.h"
#include "sched.h"
#include "thread.h"
#include "arch/thread_arch.h"
#include "arch/irq_arch.h"
/**
* @brief Initialize the CPU, set IRQ priorities
*/
void cpu_init(void)
{
/* initializes the Cortex-M core */
cortexm_init();
/* initialize the clock system */
cpu_clock_init(CLOCK_SOURCE);
}
void setup_fpu(void)
{
ROM_FPUEnable();
ROM_FPULazyStackingEnable();
}
void cpu_clock_init(int clk)
{
setup_fpu();
switch(clk){
case CLK80:
ROM_SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);
break;
case CLK50:
ROM_SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);
break;
case CLK40:
ROM_SysCtlClockSet(SYSCTL_SYSDIV_5 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);
break;
case CLK16:
ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);
break;
case CLK1:
ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_PLL | SYSCTL_XTAL_1MHZ | SYSCTL_OSC_MAIN);
break;
default:
ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);
break;
}
}