add hw_cs Python API doc

2 files changed, 15 insertions, 3 deletions

diff --git a/scripts/automation/trex_control_plane/doc_stl/api/field_engine.rst b/scripts/automation/trex_control_plane/doc_stl/api/field_engine.rst
index a6e624c1..53514455 100755
--- a/scripts/automation/trex_control_plane/doc_stl/api/field_engine.rst
+++ b/scripts/automation/trex_control_plane/doc_stl/api/field_engine.rst
@@ -125,6 +125,14 @@ STLVmWrMaskFlowVar
     :members: 
     :member-order: bysource
 
+STLVmFixChecksumHw
+--------------------
+
+.. autoclass:: trex_stl_lib.trex_stl_packet_builder_scapy.STLVmFixChecksumHw
+    :members: 
+    :member-order: bysource
+
+
 STLVmFixIpv4
 ------------------
 
@@ -154,6 +162,7 @@ STLVmFlowVarRepetableRandom
     :members: 
     :member-order: bysource
 
+
   
 
 Field Engine snippet
diff --git a/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_packet_builder_scapy.py b/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_packet_builder_scapy.py
index a868dbe8..aa002d59 100755
--- a/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_packet_builder_scapy.py
+++ b/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_packet_builder_scapy.py
@@ -782,10 +782,12 @@ class STLVmFixChecksumHw(CTRexVmDescBase):
     def __init__(self, l3_offset,l4_offset,l4_type):
         """
         Fix Ipv4 header checksum and TCP/UDP checksum using hardware assist. 
-        Use this if the packet header has changed or data payload has changed as it is necessary to change the checksum.
-        This instruction won't work on virtual interfaces only on Physical ports
+        Use this if the packet header has changed or data payload has changed as it is necessary to fix the checksums.
+        This instruction works on NICS that support this hardware offload.
 
-        Support the following packets
+        For fixing only IPv4 header checksum use STLVmFixIpv4. This instruction should be used if both L4 and L3 need to be fixed. 
+        
+        example for supported packets
 
         Ether()/(IPv4|IPv6)/(UDP|TCP)
         Ether()/(IPv4|IPv6)/(UDP|TCP)
@@ -802,6 +804,7 @@ class STLVmFixChecksumHw(CTRexVmDescBase):
 
              l4_type   : CTRexVmInsFixHwCs.L4_TYPE_UDP or CTRexVmInsFixHwCs.L4_TYPE_TCP 
 
+             see full example stl/syn_attack_fix_cs_hw.py
 
         .. code-block:: python