Achronix Speedster22i SerDes - Manual (Page 17)

Polarity and Bit Inversion – 10/20 bit Operation
When operating in 10bit/20bit mode, the bit order within each 10-bit word can be inverted.
This is illustrated in “Figure 7: 20 bit Order Reversal”. Effectively the most significant bit of
the least significant byte is transmitted first (i.e. bit 9 of byte 0 is transmitted first).
Figure 7: 20 bit Order Reversal
When the word order is reversed in 20-bit mode, the most significant byte (byte 1) is
swapped with the least significant byte (byte 0). This is illustrated in “Figure 8: 20-bit Word
Order Inversion”. The most significant byte will be transmitted first in such a case
Figure 8: 20-bit Byte Order Swap/Reversal
The polarity for the entire 10bit or 20bit word can be inverted as well. Polarity inversion
applies to the entire word (10 bits or 20 bits).
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