Question 9.PE.4: To set up a data transmission system For this exercise you w...
To set up a data transmission system
For this exercise you will need the following components and equipment:
1 – 74LS153 ic (dual 4-to-1 multiplexer)
1 – 74LS139 ic (dual 1-of-4 demultiplexer)
1 – 74LS93 ic (4-bit binary counter)
1 – 74LS04 ic (hex inverter)
1 – +5 V dc power supply
1 – clock pulse generator (Figure 1.5)
4 – LED (5 mm) and series resistor (270 Ω)
1 The outline block diagram of the system is given in Figure 9.16. For the pin connection diagrams you should refer as follows:
7493 ic – Figure 7.7
74153 ic – Figure 9.5
74139 ic – Figure 9.13
7404 ic – Figure 2.13(e)
Conclusions
1 Since all the units used in this exercise have been met earlier, you should be able to explain the action of this system.
2 Write an account of the operation of this system, taking as your basis the transfer of data D_0D_1D_2D_3 = 1101. Include in the write-up reference to all of the following:
(a) The purpose of the clock.
(b) The operation of the counter, starting from outputs Q_DQ_CQ_BQ_A = 0000.
(c) The inputs AB of both MUX and DMUX.
(d) The transfer of data from the input to output of MUX and the necessary logical state of the EN input for this transfer. Relate the logical state of this output to that of the counter.
(e) Transfer of data from input to output of DMUX and its relationship to the counter output.
(f) The need for the inverter of the DMUX output.
3 Copy out the following statements and fill in the spaces by using either the word parallel or serial, as appropriate:
(a) The input to the multiplexer is in ـــــــــ form.
(b) The output from the MUX is in ـــــــــ form.
(c) The input to the demultiplexer is in ـــــــــ form.
(d) The output from the DMUX is in ـــــــــ form.
