PM7311 pmc-sierra, PM7311 Datasheet - Page 56

• Manufacturer Part Number: PM7311
• Description: Freedm 84a1024l Assp Telecom Standard Datasheet
• Manufacturer: pmc-sierra

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2021832, Issue 2
10.1.2
Any-PHY Interface
The Any-PHY Interface is an asynchronous interface that supports the transfer of data to and from
the Any-PHY channels within the FREEDM 84A1024L. Two variants of the Any-PHY interface
are supported in FREEDM 84A1024L: a parallel 52 MHz 16 bit wide bus (Any-PHY Level 2),
and a parallel 8 bit wide 104 MHz bus (Any-PHY Level-3).
Datagrams are transferred across the interface as a series of continuous segments. A segment (see
Figure 4 to Figure 13 for examples) consists of an address/priority prepend and a fixed size of
data (except at the end of packet, when the segment may be shorter). The prepend indicates the
Any-PHY channel associated with the segment. Three segment sizes are possible (64,128,and
256 bytes.) The address prepend is not included in this segment size. A transfer will be
terminated early if the end of packet occurs before the end of a segment. The minimum
packet/frame size supported is 2 bytes.
In the egress path, only complete packets can be transferred over the Any-PHY Interface while in
the ingress path either complete packets or FRF.12 and RFC 1990 fragments may be transferred..
Begin (B) and End (E) bits are used to identify the starting fragment of a packet (B=1) and the
last fragment of a packet (E=1). When a complete packet is transferred across the interface both
bits (B and E) are set to 1.
Transmit Any-PHY Considerations
In the transmit (egress) direction, Bit 10 of the prepend indicates whether the data is high or low
priority. For single (i.e. non-multi-link) links, the Any-PHY channel is mapped to an HDLC
channel via entries in the TFRAG Any-PHY Channel RAM. For multi-link bundles, the Any-
PHY channel is mapped to a multi-link bundle via entries in the TFRAG Any-PHY Channel
RAM. Only one level of data priority is supported for multi-link bundles and the priority bit in
the prepend of multi-link data segments must be set to 0.
Provided that FIFO space is available (TPA_HI and/or TPA_LO return 1 in response to a channel
poll), the FREEDM 84A1024L expects an entire packet/fragment to be transferred. It is not
permitted to interleave the segments of packets destined for different channels, nor to interleave
segments of high-priority and low-priority packets belonging to the same channel.
The address prepend identifies the Any-PHY channel and priority associated with the segment. In
the transmit direction, the FREEDM 84A1024L uses the address prepend to index Any-PHY
channel records that indicate the configuration of the Any-PHY channel and priority. A
connection identifier is used to index connection context records that dictate how FREEDM
84A1024L should process the datagram. The connection record contains various connection
information including an indication of whether the connection is to be fragmented. A connection
identifier must be present on all PPP and FR datagrams.
It should be noted that the PID values (PID(H) and PID(L)) referenced in the following diagrams
refers to the multi-link PID = 0x003D if the connection is sequenced or the PID of the actual
datagram if the connection is non-sequenced. In the case of a sequenced connection, the first
Payload data will then be the actual PID of the datagram.
For uncompressed PPP packets, the FREEDM 84A1024L will accept any value of address and
control fields (so as not to prohibit future changes of these values).
FREEDM 84A1024L ASSP Telecom Standard Product Data Sheet
Released
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