Question 7.PE.3: To investigate the action of the 3-bit synchronous counter F...
To investigate the action of the 3-bit synchronous counter
For this exercise you will need the following components and equipment:
2 – 74LS76 ic (dual JK flipflop)
1 – 74LS08 ic (quad 2-input AND)
3 – LED red (5 mm) and resistor (270 Ω)
1 – LED green (5 mm) and resistor (270 Ω)
1 – +5 V dc power supply
1 – pulse generator (1 Hz) (see Figure 1.5)
1 – double beam cathode ray oscilloscope
1 Make up the circuit of Figure 7.10. See Figure 6.28 for the 7476 pin connections and Figure 2.13(a) for the 7408.
2 Connect the clear inputs initially to logic 0 (to reset the counter to 000) and then permanently to logic 1.
3 The clock input can again be obtained from either the +5 V supply or the generator.
4 Work through the sequence of Figure 7.9 and confirm that the counter counts from 0 to 7 and resets on the 8th pulse. In particular, for each of the eight clock pulses, check the state of the four LEDs with the expected result.
