1. Controlling Gates Enabling/Disabling Circuits & Controlled Inverters

2. The idea here is to block or unblock propagation signals

3. An enable/disable signal serves two basic purposes: 1) One is to block /unblock a data signal from further propagation. 2) The other one is to logically turn on/off logical devices (systems/subsystems)

15. What input combination of the enable signals will activate this gate?

16. {es1, es0} = {0, 1}

19. Determine the enabling input combination for these gates

20. {es2, es1, es0} = {1, 0, 1} {es3, es2, es1, es0} = {0, 1, 0, 1}

21. Timing Waveform of a 2-to-1 Line Multiplexer

23. Multiple Input Channels to a Single Output Channel

24. Can an OR gate can be used to combine different channels?

25. No. The problem is that channels might subdue each other

26. We may block a signal so that it does not subdue the other one

31. The enabling/disabling signals should be mutually exclusive. Why?

32. Enable Regions do not overlap so we are fine

33. Enable Regions overlap and this is a potential problem

34. Setting en = e_ch 0 = e_ch 1 ’ will give us mutually exclusive signals