Races in sequential circuits Races in sequential switching circuits occur when the circuit programme requires the transition between two states, the codes of which are not logically adjacent - i.e. they differ in more than one bit. It means that a race may happen only when for describing internal...
Registers Registers are such sequential circuits that their purpose is storing information. The main parameters that characterise a register are its length (equal to the number of flip-flops used in the construction) and the way of first loading data into it, then reading it. If for loading data...
Resolve unsolvable SST Resolving unsolvable SST is done by splitting SST into parts, that don't contain contradictory states. In the places of division, one or several additional elements have to be switched-on and off, to differ parts containing contradictory states. If partitioning is done well...
Structure realization Program generates following structures: • Multiplexer, • Multiplexer with gates: o NAND gates only, o NOR gates only, o AND and OR and NOT gates, • Demultiplexer, • Tree of Multiplexers, • Multiplexer - demultiplexer. The structure is chosen by a user. The menu item w...
Syntthesiis off a combiinattiionall swiittchiing ciircuiitt The aim of a synthesis of a combinational circuit is to obtain the output functions and then a logical diagram of the circuit when given its algorithm of work. The output functions of the circuit may be i n different forms but they should ...
Asynchronous counters In asynchronous counters the control inputs of flip-flops are not driven by the same signal source. The common element used in a design of such a counter is a simplified symbol of a flip-flop. By such symbol we understand any flip-flop working as a frequency divider by 2. I...
Asynchronous sequential logic circuits All switching circuits belong to one of two classes: combinational or sequential. On contrary to combinational logic circuits, the operation of sequential ones is dependent not only on the present state of external inputs, but also on the state of these inpu...
Bi nary adders Binary adder is a basic circuit performing addition operation for binary numbers A and B. This simple combinational circuit obtains two signals Si (sum) and Ci+1 (carry to next position) from signals Ai, Bi and Ci (carry from previous position). Fig. 1 presents the truth table and ...
Comparison If we use binary comparator for numbers in sign magnitude, 1's or 2's complement representation, the result isn't correct. It is caused by sign bit, which is equal 1 for negative numbers but in binary numbers has the biggest weight. To obtain correct result the negative numbers should ...
Converti ng from decimal to other number systems One of the methods used to convert from decimal to other number system is repeated radix division technique for integers and multiplication technique for fractions. During conversion process we must first break number into integer and fraction part...
