Packets received with a particular channel address must begin with a valid
Start-of-Packet (SOP). If data is detected for a particular channel without a valid SOP,
this signal is asserted for a single Local bus clock cycle. Additionally, the required
SOP is inserted before the data and an error is signaled in the End-of-Packet (EOP)
cycle via the corresponding rx_errout<N> signal.
This signal is available as a status signal to indicate a missing SOP error
condition occurred. No indication is provided on the LBUS which packet had the missing
SOP. The packet is simply marked as containing an error. This is because a missing SOP
is almost always associated with other errors that cannot be associated with a
particular packet. The purpose of SOP insertion is to ensure that packets for a
particular channel are always delivered on the RX LBUS beginning with an SOP and ending
with an EOP to remove the need for user logic to perform bus protocol checking. The
stat_rx_msop_err status signal indicates that this function is
being performed and for most applications can be ignored.