Engineering Digital Design

PROBLEMS 331

[17] The Programmable Logic Data Book. Xilinx, Inc., San Jose, CA, 1996.

[18] XACT, Logic Cell Array Macro Library. Xilinx, Inc., San Jose, CA, 1992.

PROBLEMS

7.1 A2

4

×4 ROM is to be used to implement the following system of three functions,

assuming that all inputs and outputs are active high.

y

1

(a, b, c, d) =



m(0, 1, 2, 5, 7, 8, 10, 14, 15)

y

2

(a, b, c, d) =



m(0, 2, 4, 5, 6, 7, 8, 10, 12)

y

3

(a, b, c, d) =



m(0, 1, 2, 3, 4, 6, 8, 9, 10, 11)

(a) Construct the ROM program table for this system of three functions.

(b) From the program table of part (a), construct the symbolic representation of fusible

links by following the example in Fig. 7.4.

7.2 A2

4

× 4 ROM is to be used to design and implement a BCD-to-binary module that

can be cascaded to