# 8 Tap Fir Filter Vhdl Code For Serial Adder

Thanks Francesco! Compact and very useful codes!Question: If the number of taps were generics, how can i generate the seperate process statements for the adder tree? can you give an example?Thanks!

## 8 Tap Fir Filter Vhdl Code For Serial Adder

hi dear,I need some help on one project, I want to design FIR filter in FPGA using VHDL and connect it with any medium using high-speed serial interface to observer performance of FIR filter. can anyone help me in this regards?

how we can add latch enable input in this codefor example we have 100 clock sample rate so every 100 clock , for one clock we have latch enable = 1so i_data in every 100 clock latch and filterplease help meee

Since the data is being fed sequentially, another advantage is the ability to use RAM blocks to store the data. Finally, when implementing the filter in serial, the form of the filter is far less important. In fact, the Direct Form is more suitable for serial implementation compared to the Transposed version.

In the parallel version, every multiply-add operation requires dedicated hardware. Therefore, designing extensive FIR filters can easily consume a large part of the available DSP resources(granted that the multipliers are implemented via the respective DSP resources and not LUTs and registers). This, however, is not the case with the serial implementation allowing to build filters of much greater order.

The Discrete FIR Filter block models finite-impulse response filter architectures optimized for HDL code generation. The block accepts scalar or frame-based input, and provides an option for programmable coefficients. It provides a hardware-friendly interface with input and output control signals. To provide a cycle-accurate simulation of the generated HDL code, the block models architectural latency including pipeline registers and resource sharing.

The block provides three filter structures. The direct form systolic architecture provides a fully parallel implementation that makes efficient use of Intel and Xilinx DSP blocks. The direct form transposed architecture is a fully parallel implementation and is suitable for FPGA and ASIC applications. The partly serial systolic architecture provides a configurable serial implementation that makes efficient use of FPGA DSP blocks. For a filter implementation that matches multipliers, pipeline registers, and pre-adders to the DSP configuration of your FPGA vendor, specify your target device when you generate HDL code.

The latency between valid input data and the corresponding valid output data depends on the filter structure, serialization options, the number of coefficients, and whether the coefficient values provide optimization opportunities. For details of structure and latency, see the Algorithm section.

For a filter with L coefficients, the block implements a serial filter with not more than M multipliers and requires input samples that are at least N cycles apart, such that L = NM. The block might remove multipliers when it applies coefficient optimizations, so the actual M or N value of the filter implementation can be lower than the value that you specified.

Serialization requirement for input timing, specified as a positive integer. This parameter represents N, the minimum number of cycles between valid input samples. In this case, the block calculates M = L/N. To implement a fully-serial architecture, set Number of cycles greater than the filter length, L, or to Inf.

Serialization requirement for resource usage, specified as a positive integer. This parameter represents M, the maximum number of multipliers in the filter implementation. In this case, the block calculates N = L/M. If the input data is complex, the block allocates floor(M/2) multipliers for the real part of the filter and floor(M/2) multipliers for the imaginary part of the filter. To implement a fully-serial architecture, set Number of multipliers to 1 for real input with real coefficients, 2 for complex input and real coefficients or real coefficients with complex input, or 3 for complex input and complex coefficients.

This table shows post-synthesis resource utilization for the HDL code generated for a symmetric 26-tap FIR filter with 16-bit scalar input and 16-bit coefficients. The synthesis targets a Xilinx ZC-706 (XC7Z045ffg900-2) FPGA. The Global HDL reset type parameter is Synchronous and Minimize clock enables is selected. The reset port is not enabled, so only control path registers are connected to the generated global HDL reset.

This table shows post-synthesis resource utilization for the HDL code generated from the Partly Serial Systolic FIR Filter Implementation example. The implementation is for a 32-tap FIR filter with 16-bit scalar input, 16-bit coefficients, and a serialization factor of 8 cycles between valid input samples. The synthesis targets a Xilinx Virtex-6 (XC6VLX240T-1FF1156) FPGA. The Global HDL reset type parameter is Synchronous and Minimize clock enables is selected.

This table shows post-synthesis resource utilization for the HDL code generated from the 32-tap filter in the Partly Serial Systolic FIR Filter Implementation example, with the Number of cycles parameter set to Inf. This configuration implements a fully-serial filter. The synthesis targets a Xilinx Virtex-6 (XC6VLX240T-1FF1156) FPGA. The Global HDL reset type parameter is Synchronous and Minimize clock enables is selected.

The block provides three filter structures. The direct form systolic architecture provides a fully parallel implementation that makes efficient use of Intel and Xilinx DSP blocks. The direct form transposed architecture is a fully parallel implementation and is suitable for FPGA and ASIC applications. The partly serial systolic architecture provides a configurable serial implementation that also makes efficient use of FPGA DSP blocks. For a filter implementation that matches multipliers, pipeline registers, and pre-adders to the DSP configuration of your FPGA vendor, specify your target device when you generate HDL code.

For reduced area, choose partly serial systolic architecture. Then specify a rule that the block uses to serialize the filter based on either input timing or resource usage. To specify a serial filter using an input timing rule, set Specify serialization factor as to Minimum number of cycles between valid input samples, and choose Number of cycles to be greater than or equal to 2. In this case, the filter accepts only input samples that are at least Number of cycles cycles apart. To specify a serial filter using a resource rule, set Specify serialization factor as to Maximum number of multipliers, and set Number of multipliers to be less than the number of filter coefficients. In this case, the filter accepts input samples that are at least NumCoeffs/NumMults apart.