x = -26d = -0001 1010b
[x]原 = 10001 1010b
[x]反 = 11110 0101b
1(+
---------------------------
[x]补 = 1110 1111b
y = 15d = +0000 1111b
[y]原=[y]反=[y]补= 0000 1111
x = -26d = -0001 1010b
[x]原 = 10001 1010b
[x]反 = 11110 0101b
1(+
---------------------------
[x]补 = 1110 1111b
y = 15d = +0000 1111b
[y]原=[y]反=[y]补= 0000 1111