Why does the F-Tile Ethernet Hard IP 100GE-1 Ethernet mode only allow the FEC mode to be set to “IEEE 802.3 RS(544,514) (CL 134)” when CL134 does not apply to the IEEE 802.3 RS(544,514) standard?

Description

Due to a problem in the Quartus® Prime Pro Edition software version 25.1 and earlier, the F-Tile Ethernet Hard IP 100GE-1 Ethernet mode only allows the FEC mode to be set to “IEEE 802.3 RS(544,514) (CL 134)”.

This GUI Option is incorrect for the 100GE-1 IEEE 802.3 RS(544,514) standard.
The allowable FEC modes for the 100GE-1 IEEE 802.3 RS(544,514) standard are “IEEE 802.3 RS(544, 514) (CL91)” and “IEEE 802.3 RS(544, 514) (CL161)”.
 

Resolution

To work around this problem in an application that requires a FEC mode of “IEEE 802.3 RS(544, 514) (CL91)”, perform the following Avalon® Memory-Mapped write on the Ethernet Reconfiguration Interface “i_reconfig_eth” bus:
Address = 0x66c4
Data = 0x14

To work around this problem in an application that requires a FEC mode of “IEEE 802.3 RS(544, 514) (CL161)”, select the "IEEE 802.3 RS(544,514) (CL 134)” option for FEC mode. This option actually implements the “IEEE 802.3 RS(544, 514) (CL161)” mode.

This problem is scheduled to be fixed in a future release of the Quartus® Prime Pro Edition software.