rand_num_generator.v // created by : Meher Krishna Patel // date : 22-Dec-16 // Feedback polynomial : x^3 + x^2 + 1 // maximum length : 2^3 - 1 = 7 // if parameter value is changed, // then choose the correct Feedback polynomial i.e.
PARALLEL TO SERIAL CONVERTER USING MUX AND FLIPFLOPS CODE
The code implements the design for 3 bit LFSR, which can be modified for LFSR with higher number of bits as shown below,
![parallel to serial converter using mux and flipflops parallel to serial converter using mux and flipflops](https://www.electronicshub.org/wp-content/uploads/2015/06/Serial-in-Parallel-out-shift-register-using-D-flip-flop.jpg)
Random numbers are generated using LFSR in Listing 8.1. Table 8.1 List of feedback polynomials ¶ Number of bits} Some of the polynomials are listed in Table 8.1. LFSR polynomial are written as \(x^3 + x^2 + 1\), which indicates that the feedback is provided through output of ‘ xor’ gate whose inputs are connected to positions 3, 2 and 0 of LFSR. large number of initial values are possible), then the generated numbers can be considered as random numbers for practical purposes. The sequences of random number can be predicted if the initial value is known.
![parallel to serial converter using mux and flipflops parallel to serial converter using mux and flipflops](https://www.ibiblio.org/kuphaldt/electricCircuits/Digital/04372.png)
These random numbers are generated based on initial values to LFSR. Long LFSR can be used as ‘ pseudo-random number generator’. Script execution in Quartus and ModelsimįPGA designs with Verilog and SystemVerilogĨ.2.1. Queue with first-in first-out functionality
![parallel to serial converter using mux and flipflops parallel to serial converter using mux and flipflops](https://www.ibiblio.org/kuphaldt/electricCircuits/Digital/04381.png)
The OR gates allow either the normal shifting operation or the parallel data-entry operation, depending on which of the AND gates are enabled by the level on the SHIFT / LOAD input. When a clock pulse is applied, the flip-flops with D = 1 will be set and the flip-flops withĭ = 0 will be reset, thereby storing all the four bits simultaneously. When SHIFT / LOAD is LOW, AND gates G2, G4, and G6 are enabled, allowing the data bits at the parallel inputs. When SHIFT / LOAD is HIGH, AND gates G1, G3, and G5 are enabled, allowing the data bits to shift right from one stage to the next. Now from above 4 bit parallel in serial out shift register we can see, A, B, C, and D are the four parallel data input lines and SHIFT / LOAD ( SH / LD) is a control input that allows the four bits of data at A, B, C, and D inputs to enter into the register in parallel or shift the data in serial. In bellow see the block diagram of 4 bit of parallel in serial out shift register.
![parallel to serial converter using mux and flipflops parallel to serial converter using mux and flipflops](https://media.cheggcdn.com/media%2F5cf%2F5cfc2972-0aa9-44d6-96fa-527274ab970f%2FphpxtxRPS.png)
With single clock pulse all data are enter to all 4 flip flops. Then all input are feed the inputs of different 4 number of flip flop. Let take an example suppose we have to save a 4-bit number (1011). Here the data bits are entered into the flip flops simultaneously, rather than a bit-by-bit basis. We now can develop an idea for the parallel entry of data into the register. In our previous post we discussed on Serial in parallel out shift register (SIPO) now in this post we will focus on Parallel in serial out shift register (PISO).Īs name suggests the input data will enter in parallel that means at a time to all flip flop.