x = -15d = -1111b
[x]原 =1000 1111b
[x]反 =1111 0000b
[x]补 =1111 0001b
.
x = +28d = +1 1100b
[x]原 =0001 1100b
[x]反 =0001 1100b
[x]补 =0001 1100b
.
x = -37d = -10 0101b
[x]原 =1010 0101b
[x]反 =1101 1010b
[x]补 =1101 1011b
.
x = -55d = -11 0111b
[x]原 =1011 0111b
[x]反 =1100 1000b
[x]补 =1100 1001b