Implement fixed-point sine or cosine wave using lookup table approach that exploits quarter wave symmetry
The Sine and Cosine block implements a sine and/or cosine wave in fixed point using a lookup table method that exploits quarter wave symmetry.
The Sine and Cosine block can output the following functions of the input signal, depending upon what you select for the Output formula parameter:
sin(2πu) and cos(2πu)
You define the number of lookup table points in the Number of data points for lookup table parameter. The block implementation is most efficient when you specify the lookup table data points to be (2^n)+1, where n is an integer.
Tip To obtain meaningful block output, the block input values should fall within the range [0, 1). For input values that fall outside this range, the values are cast to an unsigned data type, where overflows wrap. For these out-of-range inputs, the block output might not be meaningful.
Use the Output word length parameter to specify the word length of the fixed-point output data type. The fraction length of the output is the output word length minus 2.
The Sine and Cosine block accepts signals of the following data types:
The output of the block is a fixed-point data type.
For more information, see Data Types Supported by Simulink in the Simulink® documentation.
Select the signal(s) to output.
Specify the number of data points to retrieve from the lookup table. The implementation is most efficient when you specify the lookup table data points to be (2^n)+1, where n is an integer.
Specify the word length for the fixed-point data type of the output signal. The fraction length of the output is the output word length minus 2.
Specify the internal rule for intermediate calculations. Select Speed for faster calculations. If you do, a loss of accuracy might occur, usually up to 2 bits.
Inherited from the driving block