Question 5.[6] You are required to design a 2-bit binary adder using a NOR ROM structure. The adder adds 2-bit binary inputs X and Y, producing a 2-bit binary output Z, and the carry out signal Cout.
XXo
YYo
WLo 0000 WL1
2-bit Adder
WL2
WL3
Cout Z1 Zo
WL4
WL5
Y1Y.XXo|Cout Z1 Zo 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101
WL6 WL7 WL8
Xo X1 Yo Y1
ER ECODE WL9 WL10 WL11 WL12 WL13 WL14 WL15
Z1
Zo
a) [2] Fill in the truth table of the 2-bit adder in the space provided above. b) [3] Draw the circuitry required to implement the 2-bit adder in NOR-ROM structure in the figure above. c) [1] Should the decoder be inverting or non-inverting? Circle one of the bold-font words.
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