Parallel in serial out verilog

The length of the output from the previous test makes clear that it would be really nice if we could change the whole value of the register in one go. For that we need to add parallel input.

Note that this is not strictly needed to make the system work but it will make our lives a lot easier as we run the tests. Design of 4 to 1 Multiplexer using case statements Design of 2 to 4 Decoder using if-else statements Design of 4 to 2 Encoder using if -else statements Design of 4 to 1 Multiplexer using if -else statem Design of 4 Bit Adder cum Subtractor using xor Gat Design of 4 Bit Adder cum Subtractor using Structu Design of 4 Bit Subtractor using Structural Modeli Design of 2 to 1 Multiplexer using Gate Level Mode Visual verifications of designs 7.

Finite state machine 8. Design Examples 8. Introduction 8. Random number generator 8. Linear feedback shift register LFSR 8. Visual test 8. Shift register 8. Bidirectional shift register 8.

Parallel to serial converter 8. Serial to parallel converter 8. Random access memory RAM 8. Single port RAM 8. Visual test : single port RAM 8. Dual port RAM 8. Visual test : dual port RAM 8. Read only memory ROM 8. Queue with first-in first-out functionality 8. Queue design 8. Visual test 9. Testbenches SystemVerilog for synthesis Packages Interface Simulate and implement SoPC design The arrow after C2 indicates shifting right or down. SER input is a function of the clock as indicated by internal label 2D.

Pins P3 to P7 are understood to have the smae internal 2,3 prefix labels as P2 and P8. The CDB is a similar part except for asynchronous parallel loading of data as implied by the lack of any 2 prefix in the data label 1D for pins P1, P2, to P8.

Of course, prefix 2 in label 2D at input SER says that data is clocked into this pin. The bubble within the clock arrow indicates that activity is on the negative high to low transition clock edge. Before the slash, C4 indicates control of anything with a prefix of 4. The long arrow indicates shift right down.

Moving down below the control section to the data section, we have external inputs P0-P15 , pins , The prefix 3,4 of internal label 3,4D indicates that M3 and the clock C4 control loading of parallel data. The D stands for Data. This label is assumed to apply to all the parallel inputs, though not explicitly written out.

All other stages shift right down at clock time. Moving to the bottom of the symbol, the triangle pointing right indicates a buffer between Q and the output pin. The Triangle pointing down indicates a tri-state device. The internal logic of the SN74LS and a table summarizing the operation of the control signals is available in the link in the bullet list, top of section.

The Alarm above is controlled by a remote keypad. The alarm box supplies 5V and ground to the remote keypad to power it. Thus, we read nine key switches with four wires.

How many wires would be required if we had to run a circuit for each of the nine keys? Or, we may have used most of the pins on an pin package. We may want to reduce the number of wires running around a circuit board, machine, vehicle, or building. This will increase the reliability of our system.