Achronix Speedster22i Interlaken - Manual (Page 46)

Disabling a Single Lane
Single Transmit Lane
To disable one of the lanes in the range between 0 to ctl_tx_last_lane, the parameters
ctl_tx_has_bad_lane and ctl_tx_bad_lane are used. To enable single lane decommissioning,
ctl_tx_has_bad_lane is set to 1, and the ctl_tx_last_lane is set to the number of the SerDes lane that
is decommissioned.
For example, in an 8 lane configuration where only six lanes are active (lanes 0 to 5), to disable
lane 3, the control signals are set as follows:
• ctl_tx_last_lane = 5
• ctl_tx_has_bad_lane = 1
• ctl_tx_bad_lane = 3
The value of ctl_tx_last_lane, ctl_tx_has_bad_lane and ctl_tx_bad_lane must only be changed when
the corresponding path is held in reset.
Single Receive Lane
Disabling a single receive lane is identical to disabling a single transmit lane except the
ctl_rx_last_lane and ctl_rx_has_bad_lane inputs are used instead.
UG032, May 15, 2014 46