I generate an example design with the Virtex-6 FPGA GTH Transceiver Wizard.
I use RX OFF and divided rate.
After manually triggering GTHRESET, GTH transmitter hangs.
There is a bugin the save_state_div_sm state machine of*_gth_init.v module. After GTHRESET, it forgets to release TXPOWERDOWN.
To work around this issue, modify the state machine as follows:
default : state_div_sm <= 'DLY DONE;
default : begin state_div_sm <= 'DLY DONE; TXPOWERDOWN_OUT <= 'DLY 1'b0; end
This issue isfixed in the ISE design tools 13.4 release.