RELEASED
PM7350 S/UNI DUPLEX
DATA SHEET
PMC-1980581
ISSUE 8
DUAL SERIAL LINK PHY MULTIPLEXER
Byte
Bits
6
Mnemonic
UPCA
Description
2
The UPCA bit carries flow control
information for the microprocessor control
channel. If this bit is one, control channel
cells may be transferred.
In the event of an errored header, the
UPCA bit will be assumed to be zero. This
ensures cells are not transmitted for which
there is no buffer space.
2
5:0
PHYID
The PHY identifier determines to which
PHY a cell is destined in the downstream
direction and from which PHY it came in
the upstream direction. It also indicates
whether the cell is a stuff or control
channel cell. The field is encoded as
follows:
“111111” – Stuff cell provided for cell rate
decoupling. The payload carries no useful
data and the cell shall be discarded.
“111110” – Control channel cell. On the
transmit serial link, PHYID shall equal this
value for all cells inserted via the
Microprocessor Cell Buffer. All cells
received on the serial link with this
encoding will be routed to the local
microprocessor.
“100000” to “111101” – Reserved
“000000” to “011111” – Logical channel
index for the PHY devices.
3
7
BOC
The Bit Oriented Code (BOC) bit position
carries a repeating 16 pattern that encodes
one of 63 possible code words used for
remote control and status reporting. Five
codes are predefined to represent a
remote defect, a loopback activate request,
a loopback deactivate request, a reset
activate request and a reset deactivate
request. The remaining codes are either
reserved or user defined. The receiver
ensures the pattern is the same for 10
(default) or 5 repetitions before validating a
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
65
PMC [ PMC-SIERRA, INC ]
