Sequential logic functions, sequential nature of the behavior, feedback, sequential and temporal logic elements, synchronous and asynchronous execution
Binary memory

The need to preserve the value of signal is binary memory. Digital memory is schematically plotted in Figure 5.1. Inputs are identified by the letters "S" (as the English word set - set) and "R" (according reset - reset). Output values are complementary (opposite) and take values according to the logical table.

Fig. 5 .1: Pict. for binary memory

Table 7: Logical table for binary memory
S | R | Q |
0 | 0 | 1) | 1)
0 | 1 | 0 | 1
1 | 0 | 1 | 0
1 | 1 | 2) | 2)
0→1 | 0→1 | 0 1 or 1 0

1) the previous state

2) banned, indeterminate state; effect is such that when both inputs simultaneously change from 0 to 1, one of the outputs accidentally takes the value 0 and the second one, see the gray area of the table.

Logical function of binary memory can be implemented by connecting the two members of the "NAND" (negated logical product). The wiring is in Figure 5.2.

Pict. 5.2: Realization by using NAND

Technical realization of binary memory may be any according to the type of control variables, mechanical (Figure 5.4), electrical (Figure 5.3), hydraulic and electronic.

Fig. 5.3: Electrical realization for RS circuit
Fig. 5.4: Mechanical realization for RS circuit