RELEASED
PM7350 S/UNI-DUPLEX
DATA SHEET
PMC-1980581
ISSUE 5
DUAL SERIAL LINK PHY MULTIPLEXER
Ball
Ball
Name
Type
No. Function
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
cell.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
35
PMC [ PMC-SIERRA, INC ]
