Receive Return Rings
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 96
Receive List Placement Rules Array
The Receive List Placement Rules Array (memory offset 0x480–0x4ff) is made up of 16 combined element
registers. The combined element is actually two 32-bit registers called the Receive BD Rules Control register
(see
) and the Receive BD Rules Value/Mask register (see
). The element can be
looked at as a single 64-bit entity with a Control part and Value/Mask part since they use a single element. Bit
26 of the control part determines how the value/mask part is used. The Receive BD Rules Value/Mask register
can be used as either a 32-bit left-justified Value or a 16-bit Mask followed by a 16-bit Value.
Note:
Receive rules cannot be used to match VLAN headers because the VLAN tag is stripped from
the Ethernet frame before the rule checker runs.
Table 22: Receive BD Rules Control Register
Table 23: Receive List Placement Rules Array (memory offset 0x480–0x4ff)
Bit
Name
RW
Description
Default
31
E
RW
Enable. Enabled if set to 1
–
30
&
RW
And With Next. This rule and next must both be true to match. The class
fields must be the same. A disabled next rule is considered true.
Processor activation bits are specified in the first rule in a series.
–
29
P1
RW
If the rule matches, the processor is activated in the queue descriptor for
the Receive List Placement state machine.
–
28
P2
RW
If the rule matches, the processor is activated in the queue descriptor for
the Receive Data and Receive BD Initiator state machine.
–
27
P3
RW
If the rule matches, the processor is activated in the queue descriptor for
the Receive Data Completion state machine.
–
26
M
RW
Mask If set, specifies that the value/mask field is split into a 16-bit value
and 16-bit mask instead of a 32-bit value.
–
25
D
RW
Discard Frame if it matches the rule.
–
24
Map
RW
Map Use the masked value and map it to the class.
–
23:18
Reserved RW
Must be set to zero.
0
17:16
Op
RW
Comparison Operator specifies how to determine the match:
• 00 = Equal
• 01 = Not Equal
• 10 = Greater than
• 11 = Less Than
–