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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This is one of those rare cases where a for loop makes sense in Verilog. By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. The convertor has to deal with several potential pitfalls. This option gives a result in a single clock cycle at the expense of very deep logic levels. Therefore, the convertor works on the simulatable data structure, which is a hierarchical list of generators.

A simple two-dimensional rotation matrix is given by:. Therefore, this example has been the trigger to fix these bugs and develop MyHDL 0. The core can operate in either radian or degree mode.

A simple two-dimensional rotation matrix is given by: Rotating to zero The next step is to rotate the xv[0] and yv[0] values through the remaining phase angle, ph[0].

Otherwise, Verilog will interprete all operands in a mixed expression as unsigned. In this mode the user supplies the tangent value in x and y and the rotator seeks to minimize the y value, thus computing the angle.

### Computing sin & cos in hardware with synthesisable Verilog

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. For detailed information, you can review the wlgorithm report. After applying this calculation to a problem set with an bit phase requirement, the code above generated the following table. For example, consider how the look-up table of elementary veripog is set up in the SineComputer design:. Sign up or log in Sign up using Google.

## Cordic-based Sine Computer

Moreover, it enables fine-grained range error checking at run-time. Instead, it is a scaled rotation matrix. Obviously, MyHDL code intended for synthesis also has to take synthesis-related restrictions into account.

The next step is to rotate the xv[0] and yv[0] values through the remaining phase angle, ph[0]. In other words, T is approximately a rotation matrix. It requires only adds, subtracts, and shifts. To see this, first calculate the angles of the vectors in Fig 1 above: The pleasant consequence is that the restrictions of the “convertible subset” apply only to the code inside generator functions, not to any code outside them.

O ye simple, understand wisdom: On this page, we are mainly interested in the mechanical characteristics of the algorithm and their hardware implications. With the reset, this will require 1-FF per stage.

## Using a CORDIC to calculate sines and cosines in an FPGA

We need five registers: The precision is specified in terms of the number of bits after the point, using the parameter fractionSize. When the signal names in MyHDL and Verilog are identical we can use a little trick and simply pass the local namespace dictionary locals to the constructor. PW – algprithm ] Each rotation opportunity will set xv[0]yv[0]and ph[0].

These are the initial values of x, y, and the remaining phase to rotate through. To implement the design, we will use the Cordic algorithm, a very popular algorithm to compute trigonometric functions in hardware.

The number of stages and the number of bits in each stage can both be defined based upon arguments to the core generator program. To represent the numbers, we use the intbv class, which is basically an integer-like type with bit-vector capabilities.

The Cordic equations for this mode are:. One important feature of the convertor is that it handles the details of algirithm and unsigned representations automatically.