Hello.
Ive got a problem with simple interrupt from interval timer in uC/OS-II
System frequency is 75Mhz. There are PIO and timer. It makes strobe. Duration 10 ms. Here it is:
Timers description from system.h
I debugged this code and it works perfectly.
My project became more complicated and I had to use uC/OS-II.
This part of code is very simple and has no changes but it works very strange. Duration of strobe became about 30 ms!
After some manipulation with code I found out that functions of setting timer on are very slow.
I put line A between lines C and D. It makes duration of strobe about 16 ms.
Why simple registers writing become slow? What should I do to make it working faster?
Ive got a problem with simple interrupt from interval timer in uC/OS-II
System frequency is 75Mhz. There are PIO and timer. It makes strobe. Duration 10 ms. Here it is:
Code:
// global variablesint err;
// handler
static void handle_timer(void* context)
{
IOWR_ALTERA_AVALON_TIMER_CONTROL(timer_base, ALTERA_AVALON_TIMER_CONTROL_STOP_MSK); //disable interrupt
IOWR_ALTERA_AVALON_TIMER_STATUS(timer_base, 0); //clear flag
IOWR_ALTERA_AVALON_PIO_DATA(PIO_BASE, 1);
timer_exit();
err = 1;
return;
}
// set handler
void timer_init(alt_u32 _base, alt_u32 _interrupt, alt_u32 _irq)
{
timer_base = _base;
timer_interrupt = _interrupt;
timer_irq = _irq;
alt_ic_irq_disable (timer_interrupt, timer_irq);//disable interrupt
alt_ic_isr_register(timer_interrupt, timer_irq, handle_timer, NULL, NULL); break;
return;
}
// reset / set timeout
void timer_set_period(alt_u32 timer_period)
{
timer_period = HIGHT_RES_TIMER_LOAD_VALUE * timer_period;
IOWR_ALTERA_AVALON_TIMER_PERIODL(timer_base, timer_period&ALTERA_AVALON_TIMER_PERIODL_MSK); //write timer period l
IOWR_ALTERA_AVALON_TIMER_PERIODH(timer_base, (timer_period>>16)&ALTERA_AVALON_TIMER_PERIODH_MSK); //write timer period h
return;
}
// start counting
void timer_start(void)
{
IOWR_ALTERA_AVALON_TIMER_CONTROL(timer_base, ALTERA_AVALON_TIMER_CONTROL_STOP_MSK); //stop timer, disable interrupt
IOWR_ALTERA_AVALON_TIMER_STATUS(timer_base, 0); //clear flag
IOWR_ALTERA_AVALON_TIMER_CONTROL(timer_base, ( ALTERA_AVALON_TIMER_CONTROL_ITO_MSK |
ALTERA_AVALON_TIMER_CONTROL_START_MSK)); //start timer, enable interrupt
return;
}
// pause counting
void timer_stop(void)
{
IOWR_ALTERA_AVALON_TIMER_CONTROL(timer_base, ALTERA_AVALON_TIMER_CONTROL_STOP_MSK); //stop timer, disable interrupt
IOWR_ALTERA_AVALON_TIMER_STATUS(timer_base, 0); //clear flag
return;
}
// timer deactivation
void timer_exit(void)
{
IOWR_ALTERA_AVALON_TIMER_CONTROL(timer_base, ALTERA_AVALON_TIMER_CONTROL_STOP_MSK); //stop timer, disable interrupt
IOWR_ALTERA_AVALON_TIMER_STATUS(timer_base, 0); //clear flag
alt_ic_irq_disable (timer_interrupt, timer_irq);//disable interrupt
return;
}
// timer usage
int foo(void)
{
int nop;
err = 0;
/*A*/ IOWR_ALTERA_AVALON_PIO_DATA(PIO_BASE, 0); //set PIO
/*B*/ timer_init(HIGHT_RES_TIMER_BASE, HIGHT_RES_TIMER_IRQ_INTERRUPT_CONTROLLER_ID, HIGHT_RES_TIMER_IRQ);
/*C*/ timer_set_period(10);
/*D*/ timer_start();
while(err == 0)
{nop=0;} //waiting for timer
timer_exit();
return 1;
}Code:
/*
* hight_res_timer configuration
*
*/
#define ALT_MODULE_CLASS_hight_res_timer altera_avalon_timer
#define HIGHT_RES_TIMER_ALWAYS_RUN 0
#define HIGHT_RES_TIMER_BASE 0x1003520
#define HIGHT_RES_TIMER_COUNTER_SIZE 32
#define HIGHT_RES_TIMER_FIXED_PERIOD 0
#define HIGHT_RES_TIMER_FREQ 75000000u
#define HIGHT_RES_TIMER_IRQ 1
#define HIGHT_RES_TIMER_IRQ_INTERRUPT_CONTROLLER_ID 0
#define HIGHT_RES_TIMER_LOAD_VALUE 74ull
#define HIGHT_RES_TIMER_MULT 1.0E-6
#define HIGHT_RES_TIMER_NAME "/dev/hight_res_timer"
#define HIGHT_RES_TIMER_PERIOD 1.0
#define HIGHT_RES_TIMER_PERIOD_UNITS "us"
#define HIGHT_RES_TIMER_RESET_OUTPUT 0
#define HIGHT_RES_TIMER_SNAPSHOT 1
#define HIGHT_RES_TIMER_SPAN 32
#define HIGHT_RES_TIMER_TICKS_PER_SEC 1000000u
#define HIGHT_RES_TIMER_TIMEOUT_PULSE_OUTPUT 0My project became more complicated and I had to use uC/OS-II.
This part of code is very simple and has no changes but it works very strange. Duration of strobe became about 30 ms!
After some manipulation with code I found out that functions of setting timer on are very slow.
I put line A between lines C and D. It makes duration of strobe about 16 ms.
Why simple registers writing become slow? What should I do to make it working faster?