Shift register are the registers which are used to shift the stored bit in one or both directions. In this section, shift register is implemented which can be used for shifting data in both direction. Further it can be used as parallel to serial converter or serial to parallel converter. Verilog files required for this example are listed below,
Here, 4-bit count (i.e. parallel data) is generated using Mod-12 counter. This data is converted into serial data by Listing 8.5; and sent to Listing 8.6, where data is again converted into parallel and the result (i.e. count) is displayed at output as shown in Listing 8.7. The simulation results are shown in Fig. Fig. 8.5. Lastly, visual verification circuit is shown in Listing 8.8. Note that, empty_tick signal is used as clock for modMCounter (see red line in Fig. :numref:`fig_parallel_and_serial_design`), so that next count will be available when previous conversion is completed. Please read comments for further details.
Serial To Parallel Converter Verilog Code Examples Download https://t.co/8Xb8c4114E
A serial to parallel data conversion requires n-bit shift register. Therefore, a serial-in/parallel-out shift register converts data from serial format to parallel format. If four data bits are shifted in by four clock pulses via a single wire at serial-in, the data becomes available simultaneously on the four outputs parallel_out[3] to parallel_out[0] after the fourth clock pulse.
A serial to parallel data conversion circuit is used for converting a serial word supplied by some domain "X" to a parallel word so as to allow for the processing of the parallel word by a processor. The "X" domain supplies to the interface circuit a 'ready' pulse signal. The interface circuit, in response to the 'ready' pulse signal, supplies an 'ack' pulse and a 'clock' signal to the "X", so as to allow the serial word from the "X" to be transferred to the interface circuit, which then converts the serial word to a parallel word. An enable pulse signal supplied to the interface circuit effects the transfer of the parallel word from the interface circuit to the processor.
module serial_2_parallel ( clk_in, rst_n, ready_in, shift_enable, serial_in, ack_out, parallel_out );
// I/O declarations
input clk_in; input rst_n; input ready_in; input shift_enable; input serial_in;
output [3:0] parallel_out; reg [3:0] parallel_out; output ack_out; reg ack_out;
wire [3:0] parallel_wire;
// A 4-bit shift register to convert serial to parallel
always (posedge clk_in or negedge rst_n) begin if(rst_n == 1'b0) begin parallel_out
I'm a beginner using verilog. I am trying to make a simple parallel to serial converter (8 bits parallel down to 1 bit serial). I have 2 textbooks but I think it is way too complicated for me to understand. Right now when I try to simulate my simple Parallel-to-Serial module the input of 8-bits parallel appear but only 1 of the 8 serial bit appear. What want is for the 8 bits that comes parallel into the module to be broken up into 8 bits that come out serially. For example if I put in 11110000 as input I want 1 1 1 1 0 0 0 0 as outputs. But I only get the first of the serial bit output (1). Can anyone help? I think there might be something wrong with my testbench. I'm really not good at verilog. Hope someone can help. Thank you! Z //VERILOG PARALLEL 2 SERIAL module P2S (in_array, out1, out2, CLK, RESET, EN); input CLK, RESET, EN; input [7:0] in_array; output out1; output out2; reg out1; reg out2; integer d; begin for (d=0; d Right now when I try to simulate my simple Parallel-to-Serial module the > input of 8-bits parallel appear but only 1 of the 8 serial bit appear. > module P2S (in_array, out1, out2, CLK, RESET, EN); > input CLK, RESET, EN; > input [7:0] in_array; > output out1; > output out2; > reg out1; > reg out2; > integer d; > begin > for (d=0; d begin > out1=in_array[d]; > out2=in_array[d+1]; > end > end > endmodule The problem is that your for loop executes in 0 time steps. On the first clk edge, all iterations take place. wait for the next clock edge after each iteration should solve the problem. And the last iteration references in_array[8], which is not declared. And the RESET is not modeled. Nor the EN... Hope, this helps ;-) Lars -- Homepage: -mannheim.de/lsra/persons/lars/ computer_2(); Sun, 04 Nov 2001 03:00:00 GMT Doug Stile #3 / 3 Parallel to Serial Converter Quote:> Hello, > I'm a beginner using verilog. I am trying to make a simple parallel > to serial converter (8 bits parallel down to 1 bit serial). I have 2 > textbooks but I think it is way too complicated for me to understand. > Right now when I try to simulate my simple Parallel-to-Serial module the > input of 8-bits parallel appear but only 1 of the 8 serial bit appear. > What want is for the 8 bits that comes parallel into the module to be > broken up into 8 bits that come out serially. For example if I put in > 11110000 as input I want 1 1 1 1 0 0 0 0 as outputs. But I only get the > first of the serial bit output (1). Can anyone help? I think there might > be something wrong with my testbench. I'm really not good at verilog. > Hope someone can help. Thank you! Your code doesn't clearly spell out the reason for RESET and EN, so I don't know what you want them to do. The following code uses RESET to set the parallel register to all zeros, and the EN signal to load in a new value. For a generic p2s converter, I'd guess that you'd want a LOAD signal to load the parallel register, a SHIFT signal to enable shifting, and possibly a CLEAR to set the register to all zeros. doug ********************************************* module P2S (in_array, out1, CLK, RESET, EN); input CLK, RESET, EN; input [7:0] in_array; output out1; reg [7:0] par; reg out1; if (RESET) par
Let assume the parallel data bus of the Parallel to Serial converter to be N bit. The parallel input to the module shall be at a rate of less than or equal to 1/N clock cycles. The serializer section takes N clock cycles to output the serial data stream.
In Figure4 is reported a simulation of the parallel to serial converter VHDL code above. First serial output bit is the MSB of the input parallel data. You can choose to output first the LSB. It depends on the convention you are using. In the testbench is used a serial to parallel converter to verify the serialization. The serial to parallel conversion is identified by the signal byte in figure.
In this post, we implemented a simple example of parallel to serial VHDL code. Such a conversion strategy can be used when we need to connect two different devices like two FPGA and we need to minimize the connection wires. The clock for the data connection must run at least N times faster (where N is the number of bits to serialize).
Abstract- In the actual scenario of communication, present day chips have parallel data bus but for long distancecommunication laying down parallel channels for every bit is costlyand hardware consuming. Therefore, we use only a single channel tocommunicate between the two ports i.e. transmitter and receiver.For the receiver chips we use serial data from the channel andconvert to parallel for future use.
The task of a serial to parallel converter is to take a stream of datain serial format and for N-bit parallel converter, give N-bits asparallel output. Parallel data is required in several places likecommunication in a network, radar equipment etc. But the data cannot befed to these systems in parallel format as the external hardwarebecomes cumbersome. A serial to parallel converter comes to rescue inthese situations.
Serial to parallel convertor can also be considered as a serial-inparallel-out shift register. The basic structural component of theshift register is negative edge triggered D flip-flop. For N-bit serialto parallel convertor, N number of D flip-flops will be required.
productivity. Here comes the need of serial to parallel converter. Thetransmitter section consists of a vice-versa parallel to serialconverter and the receiver consists of serial to parallel converter.
The converters can be a N-bit, implying the output can be obtained inN-bit parallel data. The clock frequency is 100kHz and the data rate is10kHz. The data rate should be quite a factor less than clock frequencyso as to obtain correct output waveforms.
The logic circuit given below shows a serial-in-parallel-out shift register. The circuit consists of four D flip-flops which are connected. The clear (CLR) signal is connected in addition to the clock signal to all the 4 flip flops in order to RESET them. The output of the first flip flop is connected to the input of the next flip flop and so on. All these flip-flops are synchronous with each other since the same clock signal is applied to each flip flop.
The above circuit is an example of shift right register, taking the serial data input from the left side of the flip flop and producing a parallel output. They are used in communication lines where demultiplexing of a data line into several parallel lines is required because the main use of the SIPO register is to convert serial data into parallel data.
The shift register, which allows parallel input (data is given separately to each flip flop and in a simultaneous manner) and produces a serial output is known as Parallel-In Serial-Out shift register.
The logic circuit given below shows a parallel-in-serial-out shift register. The circuit consists of four D flip-flops which are connected. The clock input is directly connected to all the flip flops but the input data is connected individually to each flip flop through a multiplexer at the input of every flip flop. The output of the previous flip flop and parallel data input are connected to the input of the MUX and the output of MUX is connected to the next flip flop. All these flip-flops are synchronous with each other since the same clock signal is applied to each flip flop. eebf2c3492