4. Switch Fabric > Switch Fabric Architecture
CPS-1848 User Manual
88
June 2, 2014
Formal Status
This document is confidential and is subject to an NDA.
Integrated Device Technology
4.2
Switch Fabric Architecture
Figure 15: Switch Fabric Block Diagram
As displayed in
, the Switch Fabric contains three types of buffers:
• Input Buffer (IB) – This buffer stores packets received from the link partner.
• Crosspoint Buffers (CPB) – This buffer stores packets for an Input Buffer/Final Buffer combination. The Switch Fabric has a
matrix of Crosspoint Buffers.
• Final Buffer (FB) – This buffer stores packets to be transferred to the link partner.
Maintenance packets that are received with a hop count other than 0 (for Revision C, a hop count equal to 0) are handled as a
separate flow by the Switch Fabric. There is a separate path between each Input Buffer and the centralized Maintenance
Transactions handling block, and a separate path from the Maintenance Transactions block to each Final Buffer.
More information about buffer sizing, arbitration, and controls for buffers and transaction arbitration are discussed in the
following sections.
shows the buffer architecture of the Switch Fabric, where N is the number of ports configured
within the device.
For Revision C, maintenance packets with a hop count equal to 0 use the Maintenance Transactions
buffer.
Lanes
Ports
Lanes
Ports
Lanes
Ports
Lanes
Switch
Fabric
Registers
I2C
JTAG
Ports
Quadrant
Quadrant
Quadrant
Quadrant
FB 0
FB 1
...
FB
N
IB
N
CPB
N
, 0
CPB
N
, 1
...
CPB
N
,
N
IB 0
CPB
0, 0
CPB
0, 1
...
CP
0,
N
IB 1
CPB
1, 0
CPB
1, 1
...
CPB
1,
N
...
...
...
...
...
Maintenance
Transactions