RELEASED
PM7350 S/UNI DUPLEX
DATA SHEET
PMC-1980581
ISSUE 8
DUAL SERIAL LINK PHY MULTIPLEXER
Ball
Name
Ball
No. Function
Type
High Speed LVDS Links
OENB
I/O
P9 The active low output port enable (OENB) signal is
used to enact cell transfers from the output port.
OENB’s direction depends on the state of the
OMASTER input.
As a SCI-PHY/Utopia bus master (OMASTER = 1,
OANYPHY = 0) OENB is an output and a valid word
is output on the ODAT[15:0] bus coincidentally with
the assertion of OENB. The state of OADDR[4:0]
during the last cycle OENB was high selects the
PHY to which the cell is destined. Once asserted
low, OENB will remain low until the cell transfer is
complete.
As a bus slave (OMASTER = 0) OENB is an input.
When OENB is sampled low and the S/UNI-
DUPLEX has been selected, a word is output on
bus ODAT[15:0]. Selection occurs when OENB is
last sampled high if the OADDR[4:0] value equals
the state of the OAD[4:0] bits in the Output Address
Match register and OAVALID is sampled is its
asserted state. OENB must be low for the duration
of the cell transfer. As a SCI-PHY/Utopia slave valid
data is driven immediately upon sampling OENB
low. As a Any-PHY slave the OSX, OSOP,
ODAT[15:0] and OPRTY outputs have an additional
cycle of latency.
It is permissible to pause a cell transfer by
deasserting OENB high. As a SCI-PHY/Utopia slave
the S/UNI-DUPLEX’s must be reselected before the
cell transfer can resume. As a Any-PHY slave the
cell transfer resumes unconditionally when OENB is
asserted low again. In either case, a cell transfer
must be completed before another device on the
bus is selected.
The Any-PHY protocol supports autonomous
deselection. As an Any-PHY slave the outputs
become high impedance after the last word of a cell
is transferred until the S/UNI-DUPLEX is reselected
(via OSX) even if OENB is left asserted. As a SCI-
PHY/Utopia slave OSX is not defined, so a
subsequent cell is transferred (provided one is
available) if OENB is held low beyond the end of a
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
37
cell.
PMC [ PMC-SIERRA, INC ]
