{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Signal Generator"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%pylab inline\n",
    "pylab.rcParams['savefig.dpi'] = 300"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from caf_verilog.sig_gen import SigGen, lut_values"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fs = 625e3\n",
    "n_bits = 8\n",
    "freq_res = 200\n",
    "f_out = 20e3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "values = lut_values(n_bits)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "len(values)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "sg = SigGen(freq_res, fs, n_bits)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "sg.phase_bits"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "sg.gen_tb(f_out)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from caf_verilog.io_helper import read_complex_output"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "output_values = read_complex_output(sg.test_output_filename)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from caf_verilog.quantizer import quantize"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "vals = 40\n",
    "n = arange(0, vals)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "cref = cos(2 * pi * (f_out / fs) * n)\n",
    "cquant = quantize(cref, n_bits)\n",
    "plot(array(output_values[:vals]).real)\n",
    "plot(cquant)\n",
    "title(r'Quantized Cosine Output')\n",
    "ylabel(\"8-bit Magnitude\")\n",
    "xlabel(\"N-th Sample\")\n",
    "savefig('dds_one_cycle.png')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "sref = sin(2 * pi * (f_out / fs) * n)\n",
    "squant = quantize(sref, n_bits)\n",
    "plot(array(output_values[:vals]).imag)\n",
    "plot(squant)\n",
    "title(r'Quantized Sine Output')\n",
    "ylabel(\"8-bit Magnitude\")\n",
    "xlabel(\"N-th Sample\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "Px, ff = psd(output_values, 2**12, fs)\n",
    "plot(ff, 10*log10(Px))\n",
    "xlim([15000, 25000])\n",
    "ylim([-80, 20])\n",
    "xlabel(\"Frequency (Hz)\")\n",
    "title(\"Output Spectrum Centered at 20kHz\")\n",
    "savefig('sig_gen_8_200.png')"
   ]
  }
 ],
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