Why are FIFO full status bits in 10GBASE-R IP core swapped?

Description

In the 10GBASE-R PHY IP core version 10.1 and earlier, the TX_FIFO_FULL and RX_FIFO_FULL status bits are swapped.

Affected Configurations

This issue affects Stratix® IV and Stratix V implementations of the 10GBASE-R PHY.

Solution Status

This issue is fixed in the 10GBASE-R PHY IP core version 11.0.

Resolution

The workaround is to note that for the 10.1 and earlier release RX_FIFO_FULL is actually stored as bit 3 of address 0x82 and TX_FIFO_FULL is stored as bit 4 of address 0x82.