Performance Monitor Unit
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
12-3
ID021414
Non-Confidential
12.2
PMU functional description
This section describes the functionality of the PMU in:
•
Event interface
.
•
System register and APB interface
.
•
Counters
.
•
PMU register interfaces
.
•
External register access permissions
on page 12-4
.
Figure 12-1
shows the various major blocks inside the PMU.
Figure 12-1 PMU block diagram
12.2.1
Event interface
Events from all other units from across the design are provided to the PMU.
12.2.2
System register and APB interface
You can program the PMU registers using the system registers or external APB interface.
12.2.3
Counters
The PMU has 32-bit counters that increment when they are enabled based on events and a 64-bit
cycle counter.
12.2.4
PMU register interfaces
The Cortex-A53 processor supports access to the performance monitor registers from the
internal system register interface and a memory-mapped interface. External access to the
performance monitor registers is also provided with the APB slave port. See
External debug
interface
on page 11-37
.
Cycle Counter
Performance
Counter
Performance
Counter
Count Enable
Set/Clear
Event
Selection
Registers
CLKIN
Events from
other units
nPMUIRQ
System
Control
Processor/
APB interface
Interrupt/
Overflow
registers
Performance
Counter
Performance
Counter
Performance
Counter
Performance
Counter