单独调试定时器时，中断ok，

单独调试timestamp，ok，

结合在一起，两者都不正常工作了。

思路：timer中断换成系统计时器中断，问题来了，

中断进入了，可是不是我要的1ms中断一次啊

我的代码如下：

static alt_u16 led_cnt =0; //led 0.5s闪烁 alt_u32 my_alarm_callback (void* context)

{

led_cnt = (led_cnt <500) ? (led_cnt+1) : 0; if(led_cnt==500)

IOWR_ALTERA_AVALON_PIO_DATA(LED_BASE,0xf0);

else IOWR_ALTERA_AVALON_PIO_DATA(LED_BASE,0x0f); return SYSTICK;

}

void Myalarm_Init() //系统定时器初始化

{

alt_alarm alarm; if(alt_alarm_start(&alarm,SYSTICK,my_alarm_callback,NULL) < 0)

{

printf("Error: No system clock available\n");

} else

{

printf("Success: System clock available\n"); //printf("alt_ticks_per_second : %ld \n",alt_ticks_per_second()); }

}

led死活只有一个状态啊！！！！！！！！！！！！！！！！！

于是查看nios handbook，测试代码如下

#include

#include "system.h" //#include "sys/alt_timestamp.h" #include "sys/alt_irq.h" #include "sys/alt_alarm.h" alt_u8 alarm_rang=0;

alt_u32 my_alarm_callback (void* context)

{ /* This function is called once per second */ alarm_rang = 1; return alt_ticks_per_second(); // return value is the time when the next alarm will occur

}

int main()

{

static alt_alarm alarm;

int seconds_passed=0;

printf("Timer Example code\n"); // start the alarm to go off once per second if (alt_alarm_start (&alarm, alt_ticks_per_second(), my_alarm_callback, NULL) < 0)

{

printf ("No system clock available\n");

} while(1) if(alarm_rang==1)

{

printf("%d ",++seconds_passed);

alarm_rang=0;

} return 0;

}

运行：恍然大悟！！！！！！！！alarm是1s中断一次啊！！！！！！！！！！

难怪我led只有一个状态！！！！！！！！！！！！！！！！！！！

于是思路来了，我能不能修改alarm的时间呢。

打开alarm.h，其中有非常重要的一个注解

/*

* alt_alarm_start() can be called by an application/driver in order to register

* a function for periodic callback at the system clock frequency. Be aware that

* this callback is likely to occur in interrupt context.

*/

于是，继续查看，有一个结构体

typedef struct alt_alarm_s alt_alarm;

好家伙！没猜错的话，结构体里面应该可以修改相关参数，继续往下看

struct alt_alarm_s

{

alt_llist llist; /* linked list */

alt_u32 time; /* time in system ticks of the callback */

alt_u32 (*callback) (void* context); /* callback function. The return

* value is the period for the next callback; where

* zero indicates that the alarm should be removed

* from the list.

*/

alt_u8 rollover; /* set when desired alarm time + current time causes

overflow, to prevent premature alarm */

void* context; /* Argument for the callback */

};

终于出现了！

alt_u32 time; /* time in system ticks of the callback */

这个可以初始化呀。。。

于是。。。。。在主函数里面添加了这么一句

alarm.time = 100000;

编译运行，没有效果啊！是不是打开的方式不对？？？

再查看有什么纰漏

问题还真被我发现了，handbook提供的例程，是1s

(alt_alarm_start (&alarm, alt_ticks_per_second(), my_alarm_callback, NULL)

其中

alt_ticks_per_second()，printf查看数据

我的个亲娘，1000啊！也就是1s啊！！！这下知道怎么修改了

#define SYSTICK 51 (alt_alarm_start (&alarm,SYSTICK, my_alarm_callback, NULL)

这个好了，标准的1ms