Volume 2, Part 1: Debugging and Performance Monitoring
2:157
A counter overflow interrupt occurs when the counter wraps; i.e., a carry out from bit
W-1 is detected. Counter overflow interrupts are edge-triggered; that is, the event of a
counter incrementing and causing carry out from bit W-1 thus setting the overflow bit
and the freeze bit, generates one PMU interrupt. Provided that software does not clear
the freeze bit, while either or both of PSR.up and pp are 1, without also clearing the
overflow bit (before or concurrent with the write to the freeze bit), no further interrupts
are generated based on the fact that the carry out had been earlier detected.
show the fields in PMD and PMC respectively, while
and
describe the fields in PMD and PMC respectively.
Some implementations do not treat the upper, unimplemented bits of PMDs as ignored
bits on reads, but rather return a copy of bit W-1 in these bit positions so that count
values appear as if they were sign extended. Subsequent implementations will return 0
for these bits on reads.
Figure 7-4.
Generic Performance Counter Data Registers (PMD[4]..PMD[p])
63
W W-1
0
PMD[4]..PMD[p]
ig
count
64-W
W
Table 7-3.
Generic Performance Counter Data Register Fields
Field
Bits
Description
ig
63:W
Writes are ignored. Reads return 0.
count
W-1:0
Event Count. The counter is defined to overflow when the count field wraps (carry out
from bit W-1).
Figure 7-5.
Generic Performance Counter Configuration Register
(PMC[4]..PMC[p])
63
16 15
8 7
6
5 4 3
0
PMC[4]..PMC[p]
implementation specific
es
ig pm oi ev
plm
48
8
1
1
1 1
4
Table 7-4.
Generic Performance Counter Configuration Register Fields
(PMC[4]..PMC[p])
Field
Bits
Description
plm
3:0
Privilege Level Mask – controls performance monitor operation for a specific privilege
level. Each bit corresponds to one of the 4 privilege levels, with bit 0 corresponding to
privilege level 0, bit 1 with privilege level 1, etc. A bit value of 1 indicates that the monitor
is enabled at that privilege level. Writing zeros to all plm bits effectively disables the
monitor. In this state, the corresponding PMD register(s) do not preserve values, and
the processor may choose to power down the monitor.
ev
4
External visibility – When 1, an external notification (such as a pin or transaction) may
be provided, dependent upon implementation, whenever the monitor overflows.
Overflow occurs when a carry out from bit W-1 is detected.
oi
5
Overflow interrupt – If 1, when the monitor overflows, a Performance Monitor Interrupt is
raised and the performance monitor freeze bit (PMC[0].fr) is set. If 0, no interrupt is
raised and the performance monitor freeze bit (PMC[0].fr) remains unchanged.
Overflow occurs when a carry out from bit W-1 is detected. See
Overflow Status Registers (PMC[0]..PMC[3])”
for details on configuring interrupt
vectors.
Summary of Contents for ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
Page 1: ......
Page 11: ...x Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 13: ...1 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 33: ...1 22 Volume 1 Part 1 Introduction to the Intel Itanium Architecture ...
Page 57: ...1 46 Volume 1 Part 1 Execution Environment ...
Page 147: ...1 136 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 149: ...1 138 Volume 1 Part 2 About the Optimization Guide ...
Page 191: ...1 180 Volume 1 Part 2 Predication Control Flow and Instruction Stream ...
Page 230: ......
Page 248: ...236 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 250: ...2 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 264: ...2 16 Volume 2 Part 1 Intel Itanium System Environment ...
Page 380: ...2 132 Volume 2 Part 1 Interruptions ...
Page 398: ...2 150 Volume 2 Part 1 Register Stack Engine ...
Page 486: ...2 238 Volume 2 Part 1 IA 32 Interruption Vector Descriptions ...
Page 750: ...2 502 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 754: ...2 506 Volume 2 Part 2 About the System Programmer s Guide ...
Page 796: ...2 548 Volume 2 Part 2 Interruptions and Serialization ...
Page 808: ...2 560 Volume 2 Part 2 Context Management ...
Page 842: ...2 594 Volume 2 Part 2 Floating point System Software ...
Page 850: ...2 602 Volume 2 Part 2 IA 32 Application Support ...
Page 862: ...2 614 Volume 2 Part 2 External Interrupt Architecture ...
Page 870: ...2 622 Volume 2 Part 2 Performance Monitoring Support ...
Page 891: ......
Page 1099: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault ...
Page 1295: ...3 396 Volume 3 Resource and Dependency Semantics ...
Page 1296: ......
Page 1302: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1494: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Page 1647: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Page 1884: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Page 1885: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Page 1886: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1898: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...