[components][cputime]to be able trace before use DWT.|使用 DWT 之前必须先使能跟踪系统.

2018-06-04 14:54:07 +08:00 · 2018-06-04 14:54:07 +08:00 · e2c89ec0f5
parent 7d6b7dc3f0
commit e2c89ec0f5
1 changed files with 3 additions and 0 deletions
--- a/components/drivers/cputime/cputime_cortexm.c
+++ b/components/drivers/cputime/cputime_cortexm.c
@ -54,6 +54,9 @@ int cortexm_cputime_init(void)
    /* check support bit */
    if ((DWT->CTRL & (1UL << DWT_CTRL_NOCYCCNT_Pos)) == 0) 
    {
+        /* enable trace*/
+        CoreDebug->DEMCR |= (1UL << CoreDebug_DEMCR_TRCENA_Pos);
+        
        /* whether cycle counter not enabled */
        if ((DWT->CTRL & (1UL << DWT_CTRL_CYCCNTENA_Pos)) == 0) 
        {