diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index cd9a585e..dab7911d 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -4,11 +4,11 @@ lib_xua Change Log
 0.2.0
 -----
 
-  * ADDED:     Documentation
+  * ADDED:     Initial library documentation
   * CHANGE:    I2S hardware resources no longer used globally and must be passed
     to XUA_AudioHub()
   * CHANGE:    NO_USB define renamed to XUA_USB_EN
-  * CHANGE:    Moved to lib_spdif (from module_spdif_tx)
+  * CHANGE:    Moved to using lib_spdif (from module_spdif_tx)
 
 0.1.2
 -----
diff --git a/lib_xua/doc/rst/feat.rst b/lib_xua/doc/rst/feat.rst
index b4039911..54be90ee 100644
--- a/lib_xua/doc/rst/feat.rst
+++ b/lib_xua/doc/rst/feat.rst
@@ -4,7 +4,12 @@ Features & Options
 
 The previous sections describes only the basic core set of ``lib_xua`` details on enabling additional features e.g. S/PDIF are discussed in this section.
 
-If using the "codeless" programming model then the steps in this section are informational only.
+Where something must be defined, it is recommened this is done in `xua_conf.h` but could also be done in the application Makefile.
+
+For each feature steps are listed for if calling ``lib_xua`` functions manually - if using the "codeless" programming model then these steps informational only. 
+Each section also includes a sub-section on enabling the feature using the "codeless" model.
+
+For full details of all options please see the API section
 
 I2S/TDM
 ~~~~~~~
@@ -39,10 +44,49 @@ These hardware resources must be passed into the call to ``XUA_AudioHub()``::
     /* AudioHub/IO core does most of the audio IO i.e. I2S (also serves as a hub for all audio) */
     on tile[0]: XUA_AudioHub(c_aud, clk_audio_mclk, clk_audio_bclk, p_mclk_in, p_lrclk, p_bclk);
 
+
+Codeless Programming Model
+..........................
+
+All ports and hardware resources are already fully declared, one must simply set the following:
+
+    * `I2S_CHANS_DAC` must be set to the desired number of output channels via I2S
+    * `I2S_CHANS_ADC` must be set to the desired number of input channels via I2S
+    * `AUDIO_IO_TILE` must be set to the tile where the physical I2S connections reside 
+    
 For configuration options, master vs slave, TDM etc please see the API section.
 
+
 |newpage|
 
+S/PDIF Transmit
+~~~~~~~~~~~~~~~
+
+``lib_xua`` supports the development of devices with S/PDIF transmit functionality through the use of 
+``lib_spdif``. The XMOS S/PDIF transmitted runs in a single core and supports rates up to 192kHz.
+
+The S/PDIF transmitter core takes PCM audio samples via a channel and outputs them
+in S/PDIF format to a port. 
+
+Samples are provided to the S/PDIF transmitter task from the ``XUA_AudioHub()`` task.
+
+In order to use the S/PDIF transmmiter with ``lib_xua`` hardware resources must be declared e.g::
+
+    buffered out port:32 p_spdif_tx         = PORT_SPDIF_OUT;     /* SPDIF transmit port */
+
+
+For further details please see the documentation, application notes and examples provided for ``lib_spdif``.
+
+Codeless Programming Model
+..........................
+
+If using the codeless programming method one must simply ensure the following:
+
+    * `PORT_SPDIF_OUT` is correctly defined in the XN file
+    * `XUA_SPDIF_TX_EN` should be defined as non-zero
+    * `SPDIF_TX_TILE` is correctly defined (note, this defaults to `AUDIO_IO_TILE`)
+
+For further configuration options please see the API section.