RELEASED
PM7351 S/UNI-VORTEX
DATA SHEET
PMC-1980582
ISSUE 5
OCTAL SERIAL LINK MULTIPLEXER
12.2 Interaction Between Bus and LVDS Configurations
Since the far-end and near-end devices are configured independently it is
important to take into account how the optional fields (the Any-PHY address field,
the H5/UDF header bytes, and the user prepend word) are treated on an end-to-
end basis. The following table summarizes the possible cell format options and
summarizes the resultant impact on the cell contents at the receiving end.
Note the following:
• In general the S/UNI-VORTEX’s LVDS links will be connected to S/UNI-
DUPLEX devices. Hence the far end registers would normally reside in the
S/UNI-DUPLEX device. However, there is nothing preventing a S/UNI-
VORTEX from being connected to another S/UNI-VORTEX over the LVDS
connection. Therefore, the following tables identify register appropriate for a
S/UNI-VORTEX to S/UNI-VORTEX connection. The results are similar for a
S/UNI-VORTEX to S/UNI-DUPLEX connection except the S/UNI-DUPLEX
can function as a true Utopia L2 bus master or bus slave. Refer to the
S/UNI-DUPLEX datasheet for details.
• The downstream bus (from bus master to S/UNI-VORTEX) can only operate
in Any-PHY mode, meaning Any-PHY bus timing and addressing must be
used. However, if the Downstream Cell Interface Configuration register
(0x008) is set such that the PHY address is mapped into the H5/UDF field
(INADDUDF = 1) then the minimum length cell can be 54 bytes long rather
than Any-PHY’s default 56 byte cell.
• The upstream bus can be configured as SCI-PHY (Input pin RANYPHY = 0)
or Any-PHY (RANYPHY = 1). Setting the INADDUDF bit of register 0x00C to
1 when the bus is configured as Any-PHY has no effect. However, in SCI-
PHY mode setting the INADDUDF bit of register 0x00C to 1 and the
PREPEND bit to 0 ensures the upstream bus is Utopia L2 compliant.
• For control cells written or read via the microprocessor port, bytes 0&1
correspond to the microprocessor port’s unique PHY address field. However
since this field is fixed there is no useful information in these bytes. Bytes
10&11 are always undefined. Bytes 2&3 correspond to the user prepend
bytes, and bytes 8&9 correspond to the H5&HDF bytes. Control cells
transferred across the SCI-PHY/Any-PHY buses are formatted like all other
cells.
• The PHY address field is transported across the LVDS in an extra word
added to each user cell. Therefore it is not necessary that the H5/UDF field
be sent over the LVDS link even if the bus interfaces are configured to
embed the PHY address in the H5/UDF fields. This will slightly increase
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130
PMC [ PMC-SIERRA, INC ]
