In this section, we will discuss the Logic diagram, Timing diagram, and operation of the Asynchronous Up counter for Negative edge-triggered flip-flops. Asynchronous Up counter for Negative edge-triggered flip-flops ![]() In this clock arrangement (figure 1.1) the counter counts upwards and is known as the Up counter. Thus, in an Up counter, each flip-flop, except the LSB flip-flop, must toggle when the inverted output (Q’) of the preceding flip-flop goes from LOW to HIGH this is clearly illustrated in figure 1.2Īlso observe that, as the D flip-flops are positive edge sensitive, the inverted output (Q’) of the preceding flip-flop acts as the clock input signal for the next flip-flop and so on. when Q 1’ goes from LOW to HIGH (because Q 1’ acts as the clock input for FF2). Q 2 (MSB) changes state (toggle) each time Q 1 goes from HIGH to LOW, i.e. when Q 0’ goes from LOW to HIGH (as Q 0’ acts as the clock input for FF1). ![]() The output Q 1 changes state (toggle) every time Q 0 goes from HIGH to LOW, i.e. The output Q 0 (LSB) changes its state (toggle) at each positive transition of the clock. ![]() Figure 1.2: Timing diagram of 3-bit asynchronous binary Up counter for positive edge-triggered F/Fs.įrom the above timing diagram (figure 1.2) it is clear that this 3-bit asynchronous counter counts upwards.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |