Artesyn COMX-P4080 Installation and Use (August 2014) - Manual (Page 106)

BSP Operations
COMX-P4080 COM Express Module Installation and Use (6806800L20C) 106
7.17 SerDes
The COMX-P4080 has three Serializer/Deserializer (SerDes) banks, including a total of 18 lanes.
Twelve of these are routed to the COM-E connectors, defined as SERDES0 - SERDES7 (SERDES0-
7 of bank 1), and SERDES16 - SERDES19 (SERDES10-13 of bank 2). SERDES8-SERDES9 of bank
1 are used for Aurora debugger . The four lanes of bank 3 are not used in COMX-P4080 and are
reserved for the P30 and P50 series SATA interfaces.
For more information on the SerDes, see SerDes on page 63 . This includes the SerDes lane
distribution and options when it is routed to the COM-E connectors.
U-Boot provides "rcw" utilities to switch SerDes lanes among the twelve SerDes/RCW options.
A checking feature is also supported. Below is a usage sample of the utilities.
The steps below are used to activate specific SerDes/RCW options.
 Run "rcw active " to activate the SerDes/RCW option#.
 Power off the board.
 Set switch S1.2, S1.3 and S1.4 to "ON" or "OFF" (refer to Table "SerDes Options When
Routed to COM-E Connectors" on page 64 ) in order to correctly set up reference clocks for
SerDes banks.
 Power up the board.
rcw list - Lists the status of RCW sections
rcw active - active RCW. range [1..12]
rcw check current - Checks the current RCW with which system boots up
rcw check active - Checks the status of the active RCW section
rcw check backup
[option#] - Checks the status of all or # backup RCW section(s).
range [1..12]