Adding wip fft module

Author: aolofsson

logikbench/blocks/fft/fft.py

@@ -0,0 +1,45 @@
+import numpy as np
+from os.path import dirname, abspath
+from siliconcompiler.design import DesignSchema
+
+
+class Fft(DesignSchema):
+    def __init__(self):
+
+        name = 'fft'
+        root = f'{name}_root'
+        source = [f'rtl/{name}.v']
+
+        # create a Design object
+        super().__init__(name)
+
+        # set data home directory
+        self.register_package(root, dirname(abspath(__file__)))
+
+        # rtl files
+        fileset = 'rtl'
+        for item in source:
+            self.add_file(item, fileset, package=root)
+
+        # top module
+        self.set_topmodule(name, fileset)
+
+    def sin_table(self, width=16, size=256):
+        '''
+        Generates sin table with:
+        1 sign bit, N-1 fractional bits
+
+        '''
+        maxval = (2**(width-1)-1)
+
+        for i in range(size):
+            val = int(np.sin(2 * np.pi * i / size) * maxval)
+            if val < 0:
+                print(f"sine_lut[{i}] = -16'sd{abs(val)};")
+            else:
+                print(f"sine_lut[{i}] = 16'sd{val};")
+
+if __name__ == "__main__":
+   d = Fft()
+   d.write_fileset(f"fft.f", fileset="rtl")
+   d.sin_table()