2. Serial RapidIO Interface > Lookup Tables
38
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
The LUTs support two modes of operation, selectable on a per-port basis:
and
“Hierarchical Mode” on page 45
. Flat mode is the default mode and it supports destination IDs in the
range of 0 to 511, with a default port for destination IDs outside this range. The hierarchical model
covers the full large system range of 64-KB destination IDs, with some limitations.
To ensure high system reliability, the lookup tables are parity protected. System software must
intervene when a parity error is detected. The Tsi578 guarantees that packets are not incorrectly
delivered when the lookup table incurs single bit errors.
2.3.1
Filling the Lookup Tables
The process of filling in the LUT is composed of the following series of register writes:
•
The
“RapidIO Route Configuration DestID CSR” on page 260
is loaded with the destination ID
value to be routed
•
The
“RapidIO Route Configuration Output Port CSR” on page 261
is written with the desired
egress port number
If there is an attempt to write a destination ID with a value of greater than 511 into the
Configuration DestID CSR” on page 260
using the LRG_CFG_DESTID and CFG_DESTID fields, the
upper seven bits of the destination ID in the LRG_CFG_DESTID field is truncated.
The LUT of all the ports can be loaded simultaneously if it is desired to have the same routing entries in
all of the ports required. The loading process is similar to loading an individual port's LUT, however
alternative registers are used. The register addresses are:
•
“RapidIO Route Configuration DestID CSR” on page 260
at 0x0070 or
•
“RapidIO Port x Route Config DestID CSR” on page 314
at 0x10070
•
“RapidIO Route Configuration Output Port CSR” on page 261
at 0x0074 or
•
“RapidIO Port x Route Config Output Port CSR” on page 315
at 0x10074
The register sets are identical except that SPx_ROUTE_CFG_PORT are per-port configuration
registers and include an auto-increment bit to increment the contents of SPx_ROUTE_CFG_DESTID
after a read or write operation.
When a packet arrives at the ingress port, the destination ID of the packet is examined against
the Multicast Group Table to determine if the packet is a
multicast
).
“RapidIO Route LUT Size CAR” on page 256
only advertises the switch can map 512
destination IDs. This is due to the fact this register is global in scope, whereas the ports can be
independently configured for either flat mode or hierarchical mode lookup tables.