📄 main.c
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/*************************************************************************
*
* Used with ICCARM and AARM.
*
* (c) Copyright IAR Systems 2007
*
* File name : main.c
* Description : Define main module
*
* History :
* 1. Date : 12, September 2007
* Author : Stanimir Bonev
* Description : Create
*
* This example project shows how to use the IAR Embedded Workbench for ARM
* to develop code for the IAR LPC-2468 board. It shows basic use of the I/O,
* the timer and the interrupt controllers.
* It starts by blinking USB Link LED.
*
* Jumpers:
* J5 - depending of power source
* ISP - unfilled
* nRESET - unfilled
* EINT0 - filled
*
* Note:
* After power-up the controller get clock from internal RC oscillator that
* is unstable and may fail with J-Link auto detect, therefore adaptive clocking
* should always be used. The adaptive clock can be select from menu:
* Project->Options..., section Debugger->J-Link/J-Trace JTAG Speed - Adaptive.
*
* $Revision: 18137 $
**************************************************************************/
#include <intrinsics.h>
#include <stdio.h>
#include <nxp/iolpc2468.h>
#include "board.h"
#define TIMER0_TICK_PER_SEC 10
/*************************************************************************
* Function Name: fiq_handler
* Parameters: none
*
* Return: none
*
* Description: FIQ handler
*
*************************************************************************/
__fiq __arm void FIQ_Handler (void)
{
while(1);
}
/*************************************************************************
* Function Name: irq_handler
* Parameters: none
*
* Return: none
*
* Description: IRQ handler
*
*************************************************************************/
__irq __arm void IRQ_Handler (void)
{
void (*interrupt_function)();
unsigned int vector;
vector = VICADDRESS; // Get interrupt vector.
interrupt_function = (void(*)())vector;
if(interrupt_function != NULL)
{
interrupt_function(); // Call vectored interrupt function.
}
else
{
VICADDRESS = 0; // Clear interrupt in VIC.
}
}
/*************************************************************************
* Function Name: Timer0IntrHandler
* Parameters: none
*
* Return: none
*
* Description: Timer 0 interrupt handler
*
*************************************************************************/
void Timer0IntrHandler (void)
{
// Toggle USB Link LED
USB_LINK_LED1_FIO ^= USB_LINK_LED1_MASK;
// clear interrupt
T0IR_bit.MR0INT = 1;
VICADDRESS = 0;
}
/*************************************************************************
* Function Name: VIC_Init
* Parameters: void
* Return: void
*
* Description: Initialize VIC
*
*************************************************************************/
void VIC_Init(void)
{
volatile unsigned long * pVecAdd, *pVecCntl;
int i;
// Assign all interrupt channels to IRQ
VICINTSELECT = 0;
// Disable all interrupts
VICINTENCLEAR = 0xFFFFFFFF;
// Clear all software interrupts
VICSOFTINTCLEAR = 0xFFFFFFFF;
// VIC registers can be accessed in User or privileged mode
VICPROTECTION = 0;
// Clear interrupt
VICADDRESS = 0;
// Clear address of the Interrupt Service routine (ISR) for vectored IRQs
// and disable all vectored IRQ slots
for(i = 0, pVecCntl = &VICVECTPRIORITY0, pVecAdd = &VICVECTADDR0; i < 32; ++i)
{
*pVecCntl++ = *pVecAdd++ = 0;
}
}
/*************************************************************************
* Function Name: VIC_SetVectoredIRQ
* Parameters: void(*pIRQSub)()
* unsigned int VicIrqSlot
* unsigned int VicIntSouce
*
* Return: void
*
* Description: Init vectored interrupts
*
*************************************************************************/
void VIC_SetVectoredIRQ(void(*pIRQSub)(), unsigned int Priority,
unsigned int VicIntSource)
{
unsigned long volatile *pReg;
// load base address of vectored address registers
pReg = &VICVECTADDR0;
// Set Address of callback function to corresponding Slot
*(pReg+VicIntSource) = (unsigned long)pIRQSub;
// load base address of ctrl registers
pReg = &VICVECTPRIORITY0;
// Set source channel and enable the slot
*(pReg+VicIntSource) = Priority;
// Clear FIQ select bit
VICINTSELECT &= ~(1<<VicIntSource);
}
/*************************************************************************
* Function Name: InitClock
* Parameters: void
* Return: void
*
* Description: Initialize PLL and clocks' dividers. Hclk - 288MHz,
* Cclk- 48MHz, Usbclk - 48MHz
*
*************************************************************************/
void InitClock(void)
{
// 1. Init OSC
SCS_bit.OSCRANGE = 0;
SCS_bit.OSCEN = 1;
// 2. Wait for OSC ready
while(!SCS_bit.OSCSTAT);
// 3. Disconnect PLL
PLLCON_bit.PLLC = 0;
PLLFEED = 0xAA;
PLLFEED = 0x55;
// 4. Disable PLL
PLLCON_bit.PLLE = 0;
PLLFEED = 0xAA;
PLLFEED = 0x55;
// 5. Select source clock for PLL
CLKSRCSEL_bit.CLKSRC = 1; // Selects the main oscillator as a PLL clock source.
// 6. Set PLL settings 288 MHz
PLLCFG_bit.MSEL = 24-1;
PLLCFG_bit.NSEL = 2-1;
PLLFEED = 0xAA;
PLLFEED = 0x55;
// 7. Enable PLL
PLLCON_bit.PLLE = 1;
PLLFEED = 0xAA;
PLLFEED = 0x55;
// 8. Wait for the PLL to achieve lock
while(!PLLSTAT_bit.PLOCK);
// 9. Set clk divider settings
CCLKCFG = 6-1; // 1/6 Fpll - 48 MHz, Regarding Errata Flash.1
USBCLKCFG = 6-1; // 1/6 Fpll - 48 MHz
PCLKSEL0 = PCLKSEL1 = 0; // other peripherals - 12MHz (Fcclk/4)
// 10. Connect the PLL
PLLCON_bit.PLLC = 1;
PLLFEED = 0xAA;
PLLFEED = 0x55;
}
/*************************************************************************
* Function Name: SYS_GetFsclk
* Parameters: none
* Return: Int32U
*
* Description: return Sclk [Hz]
*
*************************************************************************/
Int32U SYS_GetFsclk(void)
{
Int32U Mul = 1, Div = 1, Osc, Fsclk;
if(PLLSTAT_bit.PLLC)
{
// when PLL is connected
Mul = PLLSTAT_bit.MSEL + 1;
Div = PLLSTAT_bit.NSEL + 1;
}
// Find clk source
switch(CLKSRCSEL_bit.CLKSRC)
{
case 0:
Osc = I_RC_OSC_FREQ;
break;
case 1:
Osc = MAIN_OSC_FREQ;
break;
case 2:
Osc = RTC_OSC_FREQ;
break;
default:
Osc = 0;
}
// Calculate system frequency
Fsclk = Osc*Mul*2;
Fsclk /= Div*(CCLKCFG+1);
return(Fsclk);
}
/*************************************************************************
* Function Name: SYS_GetFpclk
* Parameters: Int32U Periphery
* Return: Int32U
*
* Description: return Pclk [Hz]
*
*************************************************************************/
Int32U SYS_GetFpclk(Int32U Periphery)
{
Int32U Fpclk;
pInt32U pReg = (pInt32U)((Periphery < 32)?&PCLKSEL0:&PCLKSEL1);
Periphery &= 0x1F; // %32
Fpclk = SYS_GetFsclk();
// find peripheral appropriate periphery divider
switch((*pReg >> Periphery) & 3)
{
case 0:
Fpclk /= 4;
break;
case 1:
break;
case 2:
Fpclk /= 2;
break;
default:
Fpclk /= 8;
}
return(Fpclk);
}
/*************************************************************************
* Function Name: GpioInit
* Parameters: void
* Return: void
*
* Description: Reset all GPIO pins to default: primary function
*
*************************************************************************/
void GpioInit(void)
{
// Set to inputs
IO0DIR = \
IO1DIR = \
FIO0DIR = \
FIO1DIR = \
FIO2DIR = \
FIO3DIR = \
FIO4DIR = 0;
// Enable Fast GPIO0,1
SCS_bit.GPIOM = 1;
// clear mask registers
FIO0MASK =\
FIO1MASK =\
FIO2MASK =\
FIO3MASK =\
FIO4MASK = 0;
// Reset all GPIO pins to default primary function
PINSEL0 =\
PINSEL1 =\
PINSEL2 =\
PINSEL3 =\
PINSEL4 =\
PINSEL5 =\
PINSEL6 =\
PINSEL7 =\
PINSEL8 =\
PINSEL9 =\
PINSEL10= 0;
}
/*************************************************************************
* Function Name: main
* Parameters: none
*
* Return: none
*
* Description: main
*
*************************************************************************/
int main(void)
{
// MAM init
MAMCR_bit.MODECTRL = 0;
MAMTIM_bit.CYCLES = 3; // FCLK > 40 MHz
MAMCR_bit.MODECTRL = 2; // MAM functions fully enabled
// Init clock
InitClock();
// Init GPIO
GpioInit();
// Init VIC
VIC_Init();
// Init USB Link LED
USB_LINK_LED1_FDIR = USB_LINK_LED1_MASK;
USB_LINK_LED1_FSET = USB_LINK_LED1_MASK;
// Enable TIM0 clocks
PCONP_bit.PCTIM0 = 1; // enable clock
// Init Time0
T0TCR_bit.CE = 0; // counting disable
T0TCR_bit.CR = 1; // set reset
T0TCR_bit.CR = 0; // release reset
T0CTCR_bit.CTM = 0; // Timer Mode: every rising PCLK edge
T0MCR_bit.MR0I = 1; // Enable Interrupt on MR0
T0MCR_bit.MR0R = 1; // Enable reset on MR0
T0MCR_bit.MR0S = 0; // Disable stop on MR0
// set timer 0 period
T0PR = 0;
T0MR0 = SYS_GetFpclk(TIMER0_PCLK_OFFSET)/(TIMER0_TICK_PER_SEC);
// init timer 0 interrupt
T0IR_bit.MR0INT = 1; // clear pending interrupt
VIC_SetVectoredIRQ(Timer0IntrHandler,0,VIC_TIMER0);
VICINTENABLE |= 1UL << VIC_TIMER0;
T0TCR_bit.CE = 1; // counting Enable
__enable_interrupt();
while(1)
{
}
}
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