Page 264 - Engineering Digital Design

PROBLEMS 235

(b) Obtain the optimized two-level SOP results for the two functions and compare
them with the results of part (a) by using the gate/input tally (including inverters)
assuming that the inputs and outputs are all active high.
(c) Construct the logic circuits for the circuits of parts (a) and (b).
5.16 (a) Use subfunction partitioning of the following function for CRMT/two-level min-
imization in minterm code. To do this, collapse this function into a third-order
K-map of axes A, B, C and follow the discussion given in Section 5.11. Choose
{A, B, C} as the bond set for the CRMT portion.

F(A, B, C, D, E) = ^m(4, 7,10-12,14, 16-19, 21, 23, 24-27, 28, 30)

(b) Without partitioning, use the CRMT method to obtain a gate-minimum for this
function. Compare this result with that of (a) by using the gate/input tally exclusive
of inverters.
5.17 A function F is to be activated by the use of three switches, A, B, and C. It is required
that the function F be active iff a single switch is active. Thus, if any two or three of the
switches are active the function must be inactive. Design a gate minimum circuit for
the function F consisting of three XOR gates and an AND gate (nothing else). Assume
that the inputs and output are all active high. (Hint: Apply the CRMT method.)