Quality Of Service (Qos) Provision; Receive Parser - Freescale Semiconductor MPC8313E Family Reference Manual

Table 15-151. Rx Frame Control Block Descriptions (continued)
Bytes Bits Name
2–3 0–1 —
2–7 RQ
8–15 PRO
4–5 0–15 —
6–7 0–15 VLCTL
15.6.4

Quality of Service (QoS) Provision

This section describes the quality of service support features of this device. It includes a parser which
extracts vital packet properties and passes then to the filer which essentially acts as a frame classifier.
15.6.4.1

Receive Parser

The receive parser parses the incoming frame data and generates filer properties and frame control block
(FCB). The receive parser composes of the Ethernet header parser and L3/L4 parser.
The Ethernet header parser parses only L2 (ethertype) headers. It is enabled by RCTRL[PRSDEP] != 0. It
has the following key features:
• Extraction of 48-bit MAC destination and source addresses
• Extraction and recognition of the first 2-byte ethertype field
• Extraction and recognition of the final 2-byte ethertype field
• Extraction of 2-byte VLAN control field
• Walk through MPLS stack and find layer 3 protocol
• Walk through VLAN stack and find layer 3 protocol
MPC8313E PowerQUICC II Pro Integrated Processor Family Reference Manual, Rev. 3
Freescale Semiconductor
Reserved
Receive queue index. This index was selected by the eTSEC Rx Filer (from a matching Filer rule's
RQCTRL[Q] field) when it accepted the associated frame. If filing is not enabled, RQ is zero. Note
that the 3 least significant bits of RQ correspond with the RxBD ring index whenever
RCTRL[FSQEN] = 0.
If IP = 1, PRO is set as follows:
• PRO=0xFF for a fragment header or a back to back route header
• PRO=0x nn for an unrecognized header, where nn is the next protocol field
• PRO=(TCP/UDP header), as defined in the IANA specification, if TCP or UDP header is found
If IP = 0, PRO is undefined.
Note that the eTSEC parser logic stops further parsing when encountering an IP datagram that has
indicated that it has fragmented the upper layer protocol. This in general means that there is likely
no layer 4 header following the IP header and extension headers. eTSEC leaves the RxFCB[PRO]
and RQFPR[L4P] fields 0xFF in this case, which usually means that there was no IP header seen.
In this case RxFCB[IP] and optionally RxFCB[IP6] is set. IP header checksumming operates and
performs as intended. Most of the time, the eTSEC updates the RxFCB[PRO] field and
RQFPR[L4P] fileds with whatever value was found in the protocol field of the IP header. See
Section 15.5.3.3.8, "Receive Queue Filer Table Property Register
RQFPR.
Reserved
VLAN control word as per IEEE Std. 802.1Q. The lower 12 bits comprise the VLAN identifier. Valid
only if VLN = 1.
Enhanced Three-Speed Ethernet Controllers
Description
(RQFPR)," for a description of
15-165