You need to design a circuit to count people entering a restricted museum exhibit that allows

at most 7 visitors at one time. An input sensor provides an event signal which has a rising

edge whenever a person enters the area. The count can be manually reset when the room has

been cleared, and your circuit should produce an alarm signal if the count rises above 7 after

people start entering the area. This alarm signal should stay high until the system is manually

reset after the room has been cleared. You initially propose the use of a 4-bit up counter using

T-type flip-flops as shown in Figure 5.21 and described in Problem 2. You would use Q3 as

the alarm signal. However, your supervisor points out that if people continued to enter, when

the count went over 15 the alarm signal would go low again. How would you modify the T

inputs to keep Q3 high after 7 people have entered no matter how many additional people

come into the area?

for AND of increased sine for each stage, factoren Acer had the expressive Flore 5.2 the Thiement de son do the one of the con all nipo change their states i propagation on from the positive edge AND estomach the dip-Hops in the higher stages of the counter, which requires a certain the check Note that change in the value of may have to people through several - 0 0 0 Q Q Q, : 0 Q (a) Circuit Clock Q, Q, Q, Count 0 I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 (b) Timing diagram gure 5.21 A four-bit synchronous up-counter