18-90 Vol. 3B

PERFORMANCE MONITORING

For Table 19-28 and Table 19-29, Chapter 19, the name of the event is listed in the Event Name column and param-
eters that define the event and other information are listed in the Event Parameters column. The Parameter Value 
and Description columns give specific parameters for the event and additional description information. Entries in 
the Event Parameters column are described below.

•

ESCR restrictions — Lists the ESCRs that can be used to program the event. Typically only one ESCR is 
needed to count an event. 

•

Counter numbers per ESCR — Lists which performance counters are associated with each ESCR. Table 18-63 
gives the name of the counter and CCCR for each counter number. Typically only one counter is needed to count 
the event.

•

ESCR event select — Gives the value to be placed in the event select field of the ESCR to select the event.

•

ESCR event mask — Gives the value to be placed in the Event Mask field of the ESCR to select sub-events to 
be counted. The parameter value column defines the documented bits with relative bit position offset starting 
from 0, where the absolute bit position of relative offset 0 is bit 9 of the ESCR. All undocumented bits are 
reserved and should be set to 0.

•

CCCR select — Gives the value to be placed in the ESCR select field of the CCCR associated with the counter 
to select the ESCR to be used to define the event. This value is not the address of the ESCR; it is the number of 
the ESCR from the Number column in Table 18-63.

•

Event specific notes — Gives additional information about the event, such as the name of the same or a 
similar event defined for the P6 family processors.

•

Can support PEBS — Indicates if PEBS is supported for the event (only supplied for at-retirement events listed 
in Table 19-29.)

•

Requires additional MSR for tagging — Indicates which if any additional MSRs must be programmed to 
count the events (only supplied for the at-retirement events listed in Table 19-29.)

NOTE

The performance-monitoring events listed in Chapter 19, “Performance-Monitoring Events,” are 
intended to be used as guides for performance tuning. The counter values reported are not 
guaranteed to be absolutely accurate and should be used as a relative guide for tuning. Known 
discrepancies are documented where applicable.

The following procedure shows how to set up a performance counter for basic counting; that is, the counter is set 
up to count a specified event indefinitely, wrapping around whenever it reaches its maximum count. This procedure 
is continued through the following four sections.
Using information in Table 19-28, Chapter 19, an event to be counted can be selected as follows:
1. Select the event to be counted.
2. Select the ESCR to be used to select events to be counted from the ESCRs field.

ESCR Event Mask

Bit 0: MMNP
     1: MMNM
     2: MMTP
     3: MMTM

ESCR[24:9]
Branch Not-taken Predicted
Branch Not-taken Mispredicted
Branch Taken Predicted
Branch Taken Mispredicted

CCCR Select

05H

CCCR[15:13]

Event Specific Notes

P6: EMON_BR_INST_RETIRED

Can Support PEBS

No

Requires Additional 

MSRs for Tagging

No

Table 18-64.  Event Example  (Contd.)

Event Name

Event Parameters

 Parameter Value Description