+#define XT_DATA_READ() (XT_DATA_PIN&(1<<XT_DATA_BIT))
+
+#define XT_DATA_LO() do { \
+ XT_DATA_PORT &= ~(1<<XT_DATA_BIT); \
+ XT_DATA_DDR |= (1<<XT_DATA_BIT); \
+} while (0)
+
+
+#define XT_CLOCK_IN() do { \
+ XT_CLOCK_DDR &= ~(1<<XT_CLOCK_BIT); \
+ XT_CLOCK_PORT |= (1<<XT_CLOCK_BIT); \
+} while (0)