IDT Programming the Device
Revision 1.5
Integrated Device Technology, Inc.
CPS-16/12/8 User Manual
8 - 4
July 10, 2012
When a packet is received, the CPS decodes the tt field to determine if the destination ID is 16 bits or 8 bits.
If the tt field indicates that the destination ID is 16 bits:
1) The CPS divides the field into two 8-bit fields -- the domain ID and the device ID.
2) The upper 8 bits of the destination ID (the domain ID) is compared to the value programmed
into the RIO_Domain Register (0xF20020).
3) If these upper 8-bits are 0, or if upper 8-bits match the value in the domain register the CPS
device treats the packet as being within the domain of the device.
4) If a match of the above criteria occurs, the CPS uses the lower 8-bits of the packet’s destina-
tion ID field (device ID) as an address offset into the applicable Route Table to access the neces-
sary data to use for its forwarding decision.
5) If the above upper 8-bit match criteria is not met, the CPS uses the upper 8-bits, i.e. the
domain ID, as an address offset. The device uses the Domain Route Table content referenced by
this address offset for its forwarding decision.
6) If the result of the domain route table lookup is "Force-Local", a lookup into the device route
table with the lower 8 bits (config_destID) is forced.
If the destination ID is only 8 bits, CPS uses these 8 bits as a direct address offset into the route table to
obtain its forwarding information.
8.2.5 Route Table Programming
The CPS device allows the user access to each of the tables via RIO type 8 maintenance commands as
defined in the RIO Part 1 rev 1.3 specification. The CPS provides the user with the ability to program the
route tables by making associations between destination IDs and several device architectural constructs
including:
1) Output ports,
2) Multicast Mask Registers
In addition to these constructs, the device supports destination ID associations with the “default route”
action, and with the “no route” action. Note that after reset, route tables associate all destination IDs to the
default route.
Destination ID associations in the route tables are dependent upon the port configurations of the device.
The CPS supports the ability for the user to modify the QUAD_CTRL registers and the PORT_CTRL_CSRs
to configure the device’s ports. Specifically, these register definitions determine the number of ports that are
available at any time.
The device’s port configuration is as shown in the table below after reset.
Table 8.3 Port Configuration
Lane
Port
Mode
Port Number
(1x Capacity)
0
Enhanced 1x
0
1
Enhanced 1x
1
2
Enhanced 1x
2
3
Enhanced 1x
3
4
Enhanced 1x
4
5
Enhanced 1x
5
6
Enhanced 1x
6
7
Enhanced 1x
7
