Description
You may see bit errors on Rx channel 0 of transceiver block GXBL1 when you de-assert the gxb_powerdown signal of transceiver block GXBL0 when using Cyclone® IV GX EP4CGX150 and EP4CGX75 devices due to coupling inside the device.
Designs that may be affected are:
- Cyclone IV GX EP4CGX150 and EP4CGX75 devices that use transceiver banks GXBL0 and GXBL1 AND
- Rx channel 0 in transceiver bank GXBL1 is used AND
- Tx Channel 3 in transceiver bank GXBL0 is used AND
- The gxb_powerdown signals of transceiver banks GXBL0 and GXBL1 are controlled independently.
Affected designs may need to be resynchronized.
Resolution
To work around this problem, do not use the gxb_powerdown signal for transceiver bank GXBL0. Instead you can assert the pll_areset, tx_digitalreset, rx_analogreset, and rx_digitalreset signals.
