1 files changed, 5 insertions, 13 deletions
diff --git a/02-usart/include/core/system.h b/02-usart/include/core/system.h
index c836edc..a636729 100644
--- a/02-usart/include/core/system.h
+++ b/02-usart/include/core/system.h
@@ -9,20 +9,12 @@ typedef __IO struct {
 
   uint32_t reserved0;
 
-  union {
-    uint32_t stcs_r; /* SysTick Control and Status Register */
-    struct {
-      bits_t enable:1;
-      bits_t tickint:1;
-      bits_t clksource:1;
+#define scb_enable    (1 << 0)
+#define scb_tickint   (1 << 1)
+#define scb_clksource (1 << 2)
+#define scb_countflag (1 << 16)
+  uint32_t stcs_r; /* SysTick Control and Status Register */
 
-      bits_t reserved0:13;
-
-      bits_t countflag:1;
-
-      bits_t reserved1:15;
-    } stcs_bf;
-  };
   uint32_t strv_r; /* SysTick Reload Value Register */
   uint32_t stcv_r; /* SysTick Current Value Register */
   uint32_t stc_r;  /* SysTick Calibration Value Register */