4 Bit Serial Adder VHDL Code: Best Practices and Common Mistakes

A 4-bit serial adder circuit consists of two 4-bit shift registers with parallel load, a full adder, and a D-type flip-flop for storing carry-out. A simplified schematics of the circuit is shown below:

I'm trying to implement a serial adder/subtractor in VHDL, I've done it the ripple carry way before but now I'm supposed to implement the same functionality by just using one full adder cell instead of N-amount of cells so I have to shift the bits from the vectors in to the full adder/subtractor and store the result in another vector which I just shift the index for as well... The logic behind it is very easily understood, you just have a counter for the index and so on. But I obviously encounter problems since I'm probably still thinking a bit too much software programming I guess...

4 bit serial adder vhdl code

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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.

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. 2ff7e9595c