The 7 series transceivers wizard for GTP allows me to select four byte boundaries for the "Align to" option in the Comma Alignment and Equalization tab.
Do GTP transceivers support 4-byte comma alignment?
No, a Four byte boundaries value is not valid for the "Align to" option for GTP transceivers.
As per the GTP transceivers user guide Figure 4-30, 1 and 2 are the only values supported for ALIGN_COMMA_WORD.
Even though the transceivers wizard allows selection of Four byte boundaries in the "Align to" option during synthesis of the IP, the tool will produce the below critical warning indicating that a value of 4 is incorrect.
In v3.6 of the transceivers wizard, the GUI is fixed so that the four byte boundaries option is not shown in the drop down menu of the "Align to" option for GTP transceivers.