388 Hardware Reference Manual
Intel® IXP2800 Network Processor
Performance Monitor Unit
11.4.5 Threshold Events
These are the outputs of the threshold comparators. When the value in a data register is compared
to its corresponding counter value and the condition is true, a threshold event is generated.
This results in:
A pulse on the signal lines that are routed to the event’s input port (one signal line from each
comparator).
One piece of functionality this enables is to allow for CHAP commands to be completed only
when a Threshold Event occurs. In other words, a Threshold Event can be used as a Command
Trigger to control the execution of any CHAP command (start, stop, sample, etc.). See
Table 1 54.
Table 154. Chap Counter Threshold Events(Design Block # 0001)
Multiplexer # Event Name Clock
Domain
Single
pulse/
Long
pulse
Burst Description
000 Counter 0 Threshold P_CLK single separate Threshold Condition True on
Event Counter 0
001 Counter 1 Threshold P_CLK single separate Threshold Condition True on
Event Counter 1
010 Counter 2 Threshold P_CLK single separate Threshold Condition True on
Event Counter 2
011 Counter 3 Threshold P_CLK single separate Threshold Condition True on
Event Counter 3
100 Counter 4 Threshold P_CLK single separate Threshold Condition True on
Event Counter 4
101 Counter 5 Threshold P_CLK single separate Threshold Condition True on
Event Counter 5