sd2snes/src/bootldr/timer.c

61 lines
1.3 KiB
C

/* ___INGO___ */
#include <arm/NXP/LPC17xx/LPC17xx.h>
#include "bits.h"
#include "config.h"
#include "timer.h"
#include "clock.h"
#include "uart.h"
#include "sdnative.h"
/* bit definitions */
#define RITINT 0
#define RITEN 3
#define PCRIT 16
extern volatile int sd_changed;
volatile tick_t ticks;
volatile int wokefromrit;
void timer_init( void )
{
/* turn on power to RIT */
BITBANG( LPC_SC->PCONP, PCRIT ) = 1;
/* clear RIT mask */
LPC_RIT->RIMASK = 0; /*xffffffff;*/
/* PCLK = CCLK */
BITBANG( LPC_SC->PCLKSEL1, 26 ) = 1;
BITBANG( LPC_SC->PCLKSEL1, PCLK_TIMER3 ) = 1;
}
void delay_us( unsigned int time )
{
/* Prepare RIT */
LPC_RIT->RICOUNTER = 0;
LPC_RIT->RICOMPVAL = ( CONFIG_CPU_FREQUENCY / 1000000 ) * time;
LPC_RIT->RICTRL = BV( RITEN ) | BV( RITINT );
/* Wait until RIT signals an interrupt */
while ( !( BITBANG( LPC_RIT->RICTRL, RITINT ) ) ) ;
/* Disable RIT */
LPC_RIT->RICTRL = 0;
}
void delay_ms( unsigned int time )
{
/* Prepare RIT */
LPC_RIT->RICOUNTER = 0;
LPC_RIT->RICOMPVAL = ( CONFIG_CPU_FREQUENCY / 1000 ) * time;
LPC_RIT->RICTRL = BV( RITEN ) | BV( RITINT );
/* Wait until RIT signals an interrupt */
while ( !( BITBANG( LPC_RIT->RICTRL, RITINT ) ) ) ;
/* Disable RIT */
LPC_RIT->RICTRL = 0;
}