Implementation of Cordic Algorithm for FPGA. Based Computers Using Verilog. pani1, ju, a3. The CORDIC rotator seeks to reduce the angle to zero by rotating the vector. To compute . See the description of the CORDIC algorithm for details. */ module. Tags: verilog code for cordic algorithm verilog code for vector verilog code for .. specific device designations, other words log Abstract.. code in the example.

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It’s clearly neither an input nor output. We need five registers: If more iterations or higher precision calculations are desired then a new arctan table will need to be computed. However, my current simulator Cver tells me that it is. You can think of this as a series of complex rotation vectors, indexed by ksuch as those are shown in Fig 1.

The idea is to use the cos and sin functions from the math module to compute the expected results on a number of input angles, and to compare them with the outputs from the design under test. You can find more information about the convertible subset in the MyHDL manual.

Cordic Algorithm using Verilog – Electrical Engineering Stack Exchange

Further, as you may have guessed from Fig 1 above, we can apply a similar rotation going in the opposite direction: This line uses things like a list comprehension and a call dordic the trigonometric function atan from the math library, At this point, this is beyond the scope of the convertible subset, and it may stay like that forever.


Obviously, MyHDL code intended for synthesis also has to take synthesis-related restrictions into account. For more information and background on the algorithm itself, please consult other sources, such as this paper by Ray Andraka. How shall I assign port direction to angle?

For these applications, the way to compensate for the gain is to send a different number as an input. I am getting this error from days now.

The goal of this section is to rotate the input by some number of ninety-degree intervals until the remaining phase is between and The two states that we will use are 0an idle state, and 1a state indicating computation is occurring. It may be redundant in this case. The Cordic veirlog is an iterative algorithm based on vector rotations over elementary angles. Veilog, both the Verilog code for the design and the test bench stub are compiled.

Computing sin & cos in hardware with synthesisable Verilog

The resulting transform, Tis shown below: We will use this as the basis of our algorithm: Back to project URL https: This can all be done with simple integer math—no multiplies or divides are required. It may be wrong, I don’t know. Doing so, though, requires the CORDIC angles, which we needed to calculate based upon the desired precision of the output.

It is therefore defined to simply be equal to the sign bit of angle:. We may want to use the test bench for designs with different characteristics; therefore, the error margin is made a parameter. In MyHDL, a single type does it all – the intbv class. Let me get this straight: To see this, first calculate the angles of the vectors in Fig 1 above: When the signal names in MyHDL and Verilog are identical we can use a little trick and simply pass the local algoeithm dictionary locals to the constructor.


The first three are 32 bits wide, since they are storing fixed-point numbers as described above. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. In that case just drop it from the port list. Cordic-based Sine Computer Introduction Specification Slgorithm test Algorithm Design Automatic conversion to Verilog A discussion about some convertor features Taking advantage of the elaboration phase Handling negative numbers Verilog co-simulation Implementation.

Computing sin & cos in hardware with synthesisable Verilog

Hence we are rotating xv and yv in a counter-clockwise direction, while the remaining phase angle will decrease in what will look like a clock-wise direction. This can become very tricky, especially with negative numbers and the signed representation. It requires only adds, subtracts, and shifts. Some can ignore the gain.

Therefore, the convertor works on the simulatable data structure, which is a hierarchical list of generators. Then simply change the sign of the results based on this stored number.