Implementation of Cordic Algorithm for FPGA. Based Computers Using Verilog. pani1, ju, a3. If you’ve never worked with a CORDIC algorithm before, the .. Software programmers like to look at for and while loops in Verilog and think of. 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.
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Cordic Algorithm using Verilog Ask Question. You can think of this as a series of complex rotation vectors, indexed by ksuch as those are shown in Fig 1. The interface of the module looks as follows:. Note how this single-line lookup is expanded into a case statement in the Verilog output. In that case just drop it from the port list. This is of course simulator-specific. Moreover, it enables fine-grained range error checking at run-time. Other HDLs seem to try to solve the issues by creating more and more integer and bit-vector like types.
For our purposes, it can be shown that. Email Required, but never shown. The CORDIC algorithm is a clever method for accurately computing trigonometric functions using only additions, bitshifts and a small lookup table. Maybe I am not following the algorithm correctly.
Note that we have been talking about the convertible subset, and not about the “synthesizable subset”. While the data width can ostensibly be adjusted, there are a fixed number of internal arc-tangent results, each created with a fixed corvic and a fixed value.
The convertor has to deal with several potential pitfalls. With the reset, this will require 1-FF per stage.
The Verilog convertor makes this task easier. Inline mathematics generated by MathJax. The Verilog output is as follows:. On the other hand, we can access their two’s complement representation as a bit vector, for example for slicing or right-shifting. That strategy requires that for every strobe input, the output associated with that input also needs to have a high strobe output. It seems obvious that a type that unifies the integer and the bit vector views should be very useful for hardware design.
The next step is to rotate the xv and yv values through the remaining phase angle, ph. Each rotation opportunity will set xvyvand ph. This define determines the number of bits used to represent the angle. For example, consider the instantiation of the design under test in the test bench:. This module computes the sine and cosine of an input angle. Rotating to zero The next step is to rotate the xv and yv values through the remaining phase angle, ph.
The first step in building this rotation, though, is to massage the problem so that the rotation desired is less than 45 degrees.
To represent the numbers, we use the intbv class, which verolog basically an integer-like type with bit-vector capabilities. Both of these approaches used only a minimum number of clocks, although their precision was somewhat limited.
But again, these restrictions only apply to algorighm code inside generator functions, because only that code is actually converted. Ok will try and get back.
This is what we are going to try to build today. You would then have a vector that has been rotated by I am getting this error from days now. This can become very tricky, especially with negative numbers and the signed representation. Of course, we still need to make sure that the convertor gets it right, which is hard enough. Why do you think it’s is not?
The Cordic equations for this mode are:.