--- /dev/null
+<?xml version="1.0"?>
+<!--
+###################################################
+##Pad Source: IO Pads
+###################################################
+ -->
+<block>
+ <name>Pad Source</name>
+ <key>pad_source</key>
+ <make></make>
+ <param>
+ <name>Num Outputs</name>
+ <key>nports</key>
+ <value>1</value>
+ <type>int</type>
+ </param>
+ <param>
+ <name>Output Type</name>
+ <key>type</key>
+ <type>enum</type>
+ <option>
+ <name>Complex</name>
+ <key>complex</key>
+ <opt>size:gr.sizeof_gr_complex</opt>
+ </option>
+ <option>
+ <name>Float</name>
+ <key>float</key>
+ <opt>size:gr.sizeof_float</opt>
+ </option>
+ <option>
+ <name>Int</name>
+ <key>int</key>
+ <opt>size:gr.sizeof_int</opt>
+ </option>
+ <option>
+ <name>Short</name>
+ <key>short</key>
+ <opt>size:gr.sizeof_short</opt>
+ </option>
+ <option>
+ <name>Byte</name>
+ <key>byte</key>
+ <opt>size:gr.sizeof_char</opt>
+ </option>
+ </param>
+ <param>
+ <name>Vec Length</name>
+ <key>vlen</key>
+ <value>1</value>
+ <type>int</type>
+ </param>
+ <check>$vlen > 0</check>
+ <check>0 < $nports</check>
+ <source>
+ <name>out</name>
+ <type>$type</type>
+ <vlen>$vlen</vlen>
+ <nports>$nports</nports>
+ </source>
+ <doc>
+This is a source pad block for creating hierarchical flow graphs. \
+The outputs of this block will become the inputs to this flow graph when it is instantiated as a hierarchical block. \
+Limit one source pad block per flow graph.
+
+Remember to set the generate options to hier block.
+ </doc>
+</block>