1 files changed, 66 insertions, 0 deletions
diff --git a/app/util.c b/app/util.c
new file mode 100644
index 0000000..ff35288
--- /dev/null
+++ b/app/util.c
@@ -0,0 +1,66 @@
+#include "project.h"
+
+int check_parity (uint8_t *d, unsigned s, unsigned e, uint8_t p)
+{
+  unsigned i;
+
+  for (i = s; i <= e; ++i)
+    p ^= d[i];
+
+  return !p;
+}
+
+
+unsigned bcd (uint8_t *d, unsigned s, unsigned e)
+{
+  unsigned ret = 0, c, b, i;
+
+  for (i = e, c = 1, b = 0; i >= s; --i, b++) {
+
+    if (d[i]) ret += c;
+
+
+    switch (b & 3) {
+    case 0:
+    case 1:
+    case 2:
+      c <<= 1;
+      break;
+
+    default:
+      c >>= 3;
+      c *= 10;
+    }
+  }
+
+  return ret;
+}
+
+
+
+unsigned le_bcd (uint8_t *d, unsigned s, unsigned e)
+{
+  unsigned ret = 0, c, b, i;
+
+  for (i = s, c = 1, b = 0; i <= e; ++i, b++) {
+
+    if (d[i]) ret += c;
+
+
+    switch (b & 3) {
+    case 0:
+    case 1:
+    case 2:
+      c <<= 1;
+      break;
+
+    default:
+      c >>= 3;
+      c *= 10;
+    }
+  }
+
+  return ret;
+}
+
+