Digital Electronics: Principles, Devices and Applications

Counters and Registers 4631JFClockCP5-BitRing CounterCP JKFlip FlopA B C D EKA B C D EMSBLSBFFigure 11.50 Example 11.12.Table 11.15 Example 11.11.Clock pulseOutputsA B C D E F1 1 0 0 0 0 02 0 1 0 0 0 03 0 0 1 0 0 04 0 0 0 1 0 05 0 0 0 0 1 06 1 0 0 0 0 17 0 1 0 0 0 18 0 0 1 0 0 19 0 0 0 1 0 110 0 0 0 0 1 111 1 0 0 0 0 0It is very simple to write the count sequence. Firstly, we write the first 10 states of the ring counteroutput (designated by A, B, C, D and E. The logic status of F can be written by examining the logicstatus of E. F toggles whenever E undergoes ‘1’ to ‘0’ transition.Example 11.13Refer to the logic circuit arrangement of Fig. 11.51 built around an eight-bit serial-in/parallel-outshift register, type number 74164. A and B are the data inputs. The serial data feeding the registerare obtained by an ANDing operation of A and B inputs inside the IC. MR is an active LOW masterreset. Write the logic status of register outputs for the first eight clock pulses. Q 0 represents the firstflip-flop in this serial shift register.