System reset, Configuration, Define counters – Altera Embedded Peripherals IP User Manual
Page 303: Multiple clock domain considerations, Hardware simulation considerations, Software programming model, System reset -3, Configuration -3, Define counters -3, Multiple clock domain considerations -3

Offset
Register Name
Bit Description
Read
Write
31 ... 0
31 ... 1
0
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
4n + 0
T[n]
lo
section n clock cycle counter [31:0]
0 =
STOP
4n + 1
T[n]
hi
section n clock cycle counter [63:32]
0 =
START
4n + 2
Ev[n]
section n event counter
4n + 3
—
1. Reserved. Read values are undefined. When writing, set reserved bits to zero.
System Reset
After a system reset, the performance counter core is stopped and disabled, and all counters are set to
zero.
Configuration
The following sections list the available options in the MegaWizard
™
interface.
Define Counters
Choose the number of section counters you want to generate by selecting from the Number of
simultaneously-measured sections list. The performance counter core may have up to seven sections. If
you require more that seven sections, you can instantiate multiple performance counter cores.
Multiple Clock Domain Considerations
If your Qsys system uses multiple clocks, place the performance counter core in the same clock domain as
the CPU. Otherwise, it is not possible to convert cycle counts to seconds correctly.
Hardware Simulation Considerations
You can use this core in simulation with no special considerations.
Software Programming Model
The following sections describe the software programming model for the performance counter core.
UG-01085
2014.24.07
System Reset
31-3
Performance Counter Core
Altera Corporation