-128 ~ 127
-1 ~ 254
0 ~ 255
0000 0001 = 1
1111 1111 = -1
0000 0010 = 2
1111 1110 = -2
0111 1111 = 127
1000 0001 = -127
1000 0000 = -128
-128 ~ 127
-1 ~ 254
0 ~ 255
0000 0001 = 1
1111 1111 = -1
0000 0010 = 2
1111 1110 = -2
0111 1111 = 127
1000 0001 = -127
1000 0000 = -128