Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
A-194 Vol. 3
PERFORMANCE-MONITORING EVENTS
•If the PC bit is
clear, the
processor
toggles the BPMi
pins when the
counter
overflows.
If the clock ratio
is not 2:1 or 3:1,
the BPMi pins
will not function
for these
performance-
monitoring
counter events.
7BH BUS_HITM_DRV 00H
(Self)
Number of bus clock
cycles during which this
processor is driving the
HITM# pin.
Includes cycles due
to snoop stalls.
The event counts
correctly, but BPMi
(breakpoint
monitor) pins
function as follows
based on the
setting of the PC
bits (bit 19 in the
PerfEvtSel0 and
PerfEvtSel1
registers):
•If the core-clock-
to- bus-clock
ratio is 2:1 or 3:1,
and a PC bit is
set, the BPMi
pins will be
asserted for a
single clock when
the counters
overflow.
Table A-18. Events That Can Be Counted with the P6 Family Performance-
Monitoring Counters (Contd.)
Unit
Event
Num.
Mnemonic Event
Name
Unit
Mask Description Comments