Intel NETWORK PROCESSOR IXP2800 - Manual (Page 61)

Hardware Reference Manual 61
Intel
®
IXP2800 Network Processor
Technical Description
2.7.2 CSIX
CSIX-L1 (Common Switch Interface) defines an interface between a Traffic Manager (TM) and a
Switch Fabric (SF) for ATM, IP, MPLS, Ethernet, and similar data communications applications.
The Network Processor Forum (NPF) www.npforum.org, controls the CSIX-L1 specification.
The basic unit of information transferred between Traffic Managers and Switch Fabrics is called a
CFrame. There are three categories of CFrames:
• Data
• Control
• Flow Control
Associated with each CFrame is information such as length, type, address. This information is
collected by MSF and passed to Microengines.
MSF also contains a number of hardware features related to flow control.
2.7.3 Receive
Figure 12 is a simplified block diagram of the MSF receive section.
Figure 12. Simplified MSF Receive Section Block Diagram
A9365-01
Full Indication to Flow Control
CSIX CFrames mapped by RX_Port_Map CSR
(normally Flow Control CFrames are mapped here)
128
RCLK
RCLK REF
Clock
for
Receive
Functions
TXCFC
(FCIFIFO full)
TXCDAT
Full
Element
List
Receive
Thread
Freelists
Checksum
Buffers
RDAT
RCTL
RPAR
RPROT
RSTAT
(to MEs)
FCEFIFO
- - - - - -
- - - - - -
- - - - - -
- - - - - -
RBUF
- - - - - -
- - - - - -
- - - - - -
- - - - - -
SPI-4
Protocol
Logic
SPI-4
Flow
Control
CSIX
Protocol
Logic
Control
32
(to DRAM)
CSR Write
64