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VHDL Basics for Serial to Parallel Converter: A Beginner's Approach



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.




vhdl code for serial to parallel converter




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).


In this post, we analyzed the VHDL code for a parallel to serial converter. This approach is very useful in interfacing different devices. Many FPGA vendors like Xilinx, Intel/Altera give us the possibility to use internal serializer-deserializer such as a serial transceiver. In this post, we want to implement the complementary interface of the parallel to serial interface. We will see how to implement the VHDL code for a serial to parallel interface in order to get back the parallel data bus we sent in the transmitter device. In other words, we will implement the VHDL block in the of the bottom right of Figure1


Let assume the parallel data bus of the Serial to Parallel converter to be N bit. The parallel output to the module will be available every N clock cycle since N clock cycles are needed to load the shift register that provided the parallel output as in Figure2


In the VHDL code every G_N clockcycles the counter enable the parallel output register and provides theparallel data output and the relative enable pulse. With respect to theparallel to serial converter in this case no error detection logic is present.The output parallel data rate is slower than the input serial data rate, so noerror condition can occur.


In Figure4 is reported a simulation of the serial to parallel converter VHDL code above. In order to realize the test bench, the parallel to serial converter of this post is used. As a convention, the 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 this post, we implemented a simple example of a serial to parallel 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. Using a serial connection, we can minimize the number of connection wires, minimizing also the skew problem on the connection itself. This module can be used in conjunction with the serial to parallel converter discussed in this post.


This VHDL module receives serial data from the data_in line. The data is continuously shifted in. If a frame_in signal is detected, the data is latched in and the data_rdy output is asserted until the rd input is asserted by the host. The received data is available in parallel format on the data_out bus.


VHDL Code for shift register can be categorised in serial in serial out shift register, serial in parallel out shift register, parallel in parallel out shift register and parallel in serial out shift register.


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. VHDL files required for this example are listed below,


In Listing 11.7, the parallel-counter-data is converted into serial data using Listing 11.5. Then received serial data is converted back to parallel data by Listing 11.6. The simulation results are shown in Fig. 11.4


Refer following as well as links mentioned on left side panel for useful VHDL codes.D FlipflopT FlipflopRead Write RAM4X1 MUX4 bit binary counterRadix4 Butterfly16QAM Modulation2bit Parallel to serial


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.


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.


This SPI master is a flexible programmable logic component that accommodates communication with a variety of slaves via a single parallel interface. It allows communication with a user specified number of slaves, which may require independent SPI modes, data widths, and serial clock speeds.


To generate HDL code, call the generatehdl function. When the filter is a System object, you must specify a fixed-point data type for the input data. To generate a partly serial architecture, specify a serial partition. To enable CoefficientMemory property, you must set CoefficientSource to ProcessorInterface.


Generate a fully serial architecture by setting the partition size to the effective filter length. The system clock rate is six times the input sample rate. The reported HDL latency is one sample greater than the default parallel implementation.


Generate a partly serial architecture with three equal partitions. This architecture uses three multipliers. The clock rate is two times the input rate, and the latency is the same as the default parallel implementation.


Select a serial partition vector for a target of two multipliers, and pass the vectors to the generatehdl function. Calling the function this way returns the first possible partition vector, but there are multiple partition vectors that achieve a two-multiplier architecture. Each stage uses a different clock rate based on the number of multipliers. The coder generates a timing controller to derive these clocks.


To generate HDL code, call the generatehdl function with one of the serial architectures. Specify either the NumMultipliers or FoldingFactor property, but not both. For instance, using the NumMultipliers property:


Create a direct-form symmetric FIR filter with a fully parallel (default) architecture. Define the coefficients for the filter object in the vector b. The coder generates test bench code to test the coefficient interface using a second set of coefficients, c. The coder trims c to the effective length of the filter.


Create a polyphase sample rate converter. By default, the coder generates a single input clock (clk), an input clock enable (clk_enable), and a clock enable output signal named ce_out. The ce_out signal indicates when an output sample is ready. The ce_in output signal indicates when an input sample was accepted. You can use this signal to control the upstream data flow.


CHAPTER 1: INTRODUCTION TO DIGITAL ELECTRONICS * Basics. - Digital and analog signals. Definition and characteristics. - Digital electronics. Applications. CHAPTER 2: DIGITAL REPRESENTATION OF THE INFORMATION * Digital representation of the information. - Information concept and unit of information. - Information codification. * Numeral systems. - Binary numeral system. - Octal numeral system. - Hexadecimal numeral system. - System conversion. * Binary codes. - Natural binary code. - Decimal codes expressed in binary code: BCD, Excess-3 BCD. - Cyclic and continuous binary codes: Gray and Johnson. - Representation of signed numbers. - Representation of fixed point and floating point numbers. - Alphanumeric codes: ASCII. - Applications. CHAPTER 3: BOOLEAN ALGEBRA. LOGIC FUNCTIONS * Boolean algebra. - Boolean algebra postulates. - Boolean algebra theorems. * Logic functions. - Definition of logic variable. - Definition of logic function. - Representation of logic functions. Truth table. - Basic logic functions and their symbols (logic gates). - Complete sets of logic gates. - Function generation with logic gates. * Simplification with logic functions. - Simplification by application of theorems. - Canonical forms for a logic function. Synthesis by minterms and maxterms. - Simplification with Karnaugh maps. Examples. - Simplification of incomplete functions. - Simplification of multifunctions. CHAPTER 4: DIGITAL ARITHMETIC SYSTEMS * Binary arithmetic. - Introduction. - Arithmetic operations in binary natural code. Binary addition. Binary substraction. Substraction as an addition: Representation of negative numbers in ones complement and in twos complement. Binary multiplication. - Arithmetic operations in BCD: addition and substraction. * Arithmetic circuit. - Basic half-adder. - Complete adder. - Parallel adder with serial carry. - Parallel adder with parallel carry. - Serial adder. - Basic half-substracter. - Complete substracter. - Adder-substracter. - Binary multiplier. - Arithmetic Logic Unit (ALU). CHAPTER 5: OTHER COMBINATIONAL SYSTEMS * Combinational circuits and subsystems. - Combinational circuit concept. - Digital multiplexer. Multiplexer extension. Applications of multiplexers: parallel-serial conversion. Generation of functions. - Encoders. Standard encoders. Priority encoders. - Decoders. Mutual exclusive output decoders. Driver decoders. Decoder extension. Decoder applications: serial-parallel conversion (demultiplexers). Generation of logical functions. - Code coverters. - Parity generator and checker. Parity generator and checker extension. - Binary comparator. Comparator extension. CHAPTER 6: SEQUENTIAL SYSTEMS * Flip-flop circuits. - Sequential system definition. - Types and characteristics: asynchronous and synchronous. - R S flip-flop. - J K flip-flop. - T flip-flop. - D flip-flop. - Flip-flop timing parameters. * Shift registers. - Register concept. - Shift registers. Serial input, serial output. Serial input, parallel output. Parallel input, serial output. Parallel input, parallel output. - Bidirectional register. - Applications of registers. Sequence generator. * Counters. - Digital counters. - Asynchronous counters. Decade counter. - Synchronous counters. Serial and parallel carry. - Reversible counter. - Counters based on shift registers. Ring counter. Johnson counter. Anti-lockout counter. - Applications. * Analysis and design of synchronous sequential circuits. - Analysis of synchronous sequential circuits. - Transition tables and state diagrams: Mealy and Moore machine state. - Synthesis of synchronous sequential systems. 2ff7e9595c


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