diff --git a/include/common/tdataformat.h b/include/common/tdataformat.h
index b9ce7368a7b5e4e3fb369b8e4feefacd55bb8c33..af7c88acded2e151ff730ccb1ade5fdf15f9862a 100644
--- a/include/common/tdataformat.h
+++ b/include/common/tdataformat.h
@@ -43,11 +43,12 @@ const static uint8_t BIT2_MAP[4][4] = {{0b00000000, 0b00000001, 0b00000010, 0},
                                        {0b00000000, 0b00010000, 0b00100000, 4},
                                        {0b00000000, 0b01000000, 0b10000000, 6}};
 
+#define N1(n)             ((((uint8_t)1) << (n)) - 1)
 #define BIT1_SIZE(n)      ((((n)-1) >> 3) + 1)
 #define BIT2_SIZE(n)      ((((n)-1) >> 2) + 1)
-#define SET_BIT1(p, i, v) ((p)[(i) >> 3] |= (((uint8_t)v) << ((i)&7)))
+#define SET_BIT1(p, i, v) ((p)[(i) >> 3] = (p)[(i) >> 3] & N1((i)&7) | (((uint8_t)(v)) << ((i)&7)))
 #define GET_BIT1(p, i)    (((p)[(i) >> 3] >> ((i)&7)) & ((uint8_t)1))
-#define SET_BIT2(p, i, v) ((p)[(i) >> 2] |= BIT2_MAP[(i)&3][v])
+#define SET_BIT2(p, i, v) ((p)[(i) >> 2] = (p)[(i) >> 2] & N1(BIT2_MAP[(i)&3][3]) | BIT2_MAP[(i)&3][(v)])
 #define GET_BIT2(p, i)    (((p)[(i) >> 2] >> BIT2_MAP[(i)&3][3]) & ((uint8_t)3))
 
 // STSchema