1 files changed, 59 insertions, 3 deletions

diff --git a/app/abs.c b/app/abs.c
index 2ed8dd4..7a6b5d5 100644
--- a/app/abs.c
+++ b/app/abs.c
@@ -3,11 +3,14 @@
 
 static uint32_t high_tick;
 
+#if HW_CLOCK_LEN == 32
+
 #define QUARTER (1UL << 29)
 #define HALF (1UL << 30)
 #define THREE_QUARTERS (HALF+QUARTER)
 #define ONE (~(uint32_t)0)
 
+
 uint64_t abs_extend (uint32_t now)
 {
   static int m;
@@ -25,9 +28,7 @@ uint64_t abs_extend (uint32_t now)
       m = 1;
     }
 
-
   } else {
-
     if (now < HALF) {
       ret = high_tick;
       ret <<= 32;
@@ -44,6 +45,61 @@ uint64_t abs_extend (uint32_t now)
 
   return ret;
 }
+#elif HW_CLOCK_LEN == 31
+
+#define QUARTER (1UL << 28)
+#define HALF (1UL << 29)
+#define THREE_QUARTERS (HALF+QUARTER)
+#define ONE (0x7fffffff)
+
+
+uint64_t abs_extend (uint32_t now)
+{
+  static int m;
+  uint64_t ret;
+
+
+  if (!m) {
+    ret = high_tick;
+    ret <<= 31;
+    ret |= now;
+
+    if ((now > THREE_QUARTERS) && (now <= ONE)) {
+      high_tick++;
+      m = 1;
+    }
+
+  } else {
+    if (now < HALF) {
+      ret = high_tick;
+      ret <<= 31;
+      ret |= now;
+    } else {
+      ret = high_tick - 1;
+      ret <<= 31;
+      ret |= now;
+    }
+
+    if ((now > QUARTER) && (now < HALF))
+      m = 0;
+  }
+
+  return ret;
+}
+
+
+
+
+
+#else
+#error unknown hardware clock length
+#endif
+
+
+
+
+
+
 
 
 void abs_meh (void)
@@ -57,7 +113,7 @@ void abs_meh (void)
 
 uint64_t abs_get (void)
 {
-  uint32_t now = SCS_DWT_CYCCNT;
+  uint32_t now = HW_CLOCK_REG;
   return abs_extend (now);
 }