The reset signals are used to set the Aurora 8B/10B core to a known starting state. On reset, the core stops any current operation and re-initializes a new channel.
On full-duplex modules, the reset signal resets both the TX and RX sides of the channel. On simplex modules, tx_system_reset resets TX channels and rx_system_reset resets RX channels. The gt_reset signal resets the transceivers which eventually resets the core.
Note: The tx_system_reset is separate from the tx_reset and rx_reset signals used on the simplex sideband interface.