docs: Add util_extract IP core

Signed-off-by: Jorge Marques <jorge.marques@analog.com>

Author: gastmaier

docs/library/util_extract/index.rst

@@ -0,0 +1,56 @@
+.. _util_extract:
+
+Util Extract
+===============================================================================
+
+.. hdl-component-diagram::
+
+The :git-hdl:`Util Extract <library/util_extract>` core
+allows the extraction of the trigger signal and restoration of the data signal
+that was embedded in the data stream by the :ref:`axi_adc_trigger`.
+
+Files
+--------------------------------------------------------------------------------
+
+.. list-table::
+   :header-rows: 1
+
+   * - Name
+     - Description
+   * - :git-hdl:`library/util_extract/util_extract.v`
+     - Verilog source for the peripheral.
+
+Configuration Parameters
+--------------------------------------------------------------------------------
+
+.. hdl-parameters::
+
+   * - NUM_OF_CHANNELS
+     - Number of channels
+   * - DATA_WIDTH
+     - Data width. It assumes the trigger is in bit (n*16)-1, with n being the
+       channel number
+
+Interface
+--------------------------------------------------------------------------------
+
+.. hdl-interfaces::
+
+   * - clk
+     - Clock input. Should be synchronous to the input and the output data
+   * - data_in
+     - Input data from the FIFO. Will replace each trigger bit with the sign
+       extended version of the data. It should be data from the output of the
+       variable fifo
+   * - data_in_trigger
+     - Data from which the trigger is extracted. It should be data from the
+       input of the variable fifo
+   * - data_valid
+     - Valid for the input data
+   * - data_out
+     - Data without the embedded trigger
+   * - valid_out
+     - Valid for the output data
+   * - trigger_out
+     - Trigger output. Is an logic OR of the triggers from all the channels
+       that are captured simulaneously