103 學年度第一學期 數位電路學 期中考試
範圍：Ch. 5-5 ~ Ch. 6
上課教師：潘欣泰
日期：103/11/11
1. (24%) Design JK and T flip-flop by using D-type flip-flop. Moreover, write down the characteristic
tables and excitation tables for JK and T flip-flops.
Ans:
參考下表
2. (15%) Design a sequential circuit with two D flip-flops A and B and one input X. When X=1, the
state of the circuit remains the same. When X=0, the circuit goes through the state transitions from
00 to 10 to 11 to 01, back to 00, and then repeats.
Ans:
第 1 頁，共 5 頁
103 學年度第一學期 數位電路學 期中考試
範圍：Ch. 5-5 ~ Ch. 6
上課教師：潘欣泰
日期：103/11/11
3. (10%) Find the CMOS switch model networks for the following functions:
(1) 3-input NAND gate
(2) 2-input OR gate (Hint: By combining a 2-input NOR gate and an inverter)
Ans:
(1)
(2)
4. (10%) Suppose that all the flip-flops used are the same and have
tpd = 0.2 ns
ts= 0.1 ns
largest (longest path) tpd,COMB= 1.3 ns
Find the minimum clock period tp and the maximum frequency fmax for Fig. 1.
Ans:
tp >= 1.6ns, fmax=625 MHz
第 2 頁，共 5 頁
103 學年度第一學期 數位電路學 期中考試
範圍：Ch. 5-5 ~ Ch. 6
上課教師：潘欣泰
日期：103/11/11
Fig. 1 Figure for problem 4.
5. (15%) Assume that tpd is the average of tPHL and tPLH. Find the delay from each input to the output in
Fig. 2 by
(1) Finding tPHL and tPLH for each path, assuming tPHL =0.10 ns and tPLH =0.22 ns for each gate.
From these values, find tpd for each path.
(2) Using tpd =0.16 ns for each gate.
(3) Compare your answers in part (1) and (2) and discuss any differences.
Fig. 2 Figure for Problem 5.
Ans:
第 3 頁，共 5 頁
103 學年度第一學期 數位電路學 期中考試
範圍：Ch. 5-5 ~ Ch. 6
上課教師：潘欣泰
日期：103/11/11
6. (16%) Tabulate the truth table for an 16×4 ROM that implements the following four Boolean
functions:
A( X , Y , Z )   m(1, 3, 5)
B( X , Y , Z )   m(3, 4, 7)
C ( X , Y , Z )   m(1, 2, 5, 7)
A( X , Y , Z )   m(2, 3, 5, 6, 7)
Ans:
7. (10%) Given a 512×8 ROM chip with an enable input, show the external connections necessary to
construct a 2K×32 ROM with sixteen chips and a decoder.
Ans:
8. (10%) Write down the Boolean function F1 and F2 implemented in Fig. 3.
Ans:
F1  AB  AC  A BC
F2  AC  BC
第 4 頁，共 5 頁
103 學年度第一學期 數位電路學 期中考試
範圍：Ch. 5-5 ~ Ch. 6
上課教師：潘欣泰
Fig. 3 Figure for problem 8.
第 5 頁，共 5 頁
日期：103/11/11