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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
August 2006
Developer’s Manual
Order Number: 306262-004US
159
Intel XScale
®
Processor—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
3.7.2.3
Performance Monitor Control Register
The performance monitor control register (PMNC) is a coprocessor register that:
• Contains the PMU ID
• Extends CCNT counting by six more bits (cycles between counter rollover = 2
38
)
• Resets all counters to zero
• And enables the entire mechanism
shows the format of the PMNC register.
3.7.2.4
Interrupt Enable Register
Each counter can generate an interrupt request when it overflows. INTEN enables
interrupt requesting for each counter.
Table 59.
Performance Monitor Control Register
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
ID
D C P E
reset value: E and ID are 0, others unpredictable
Bits
Access
Description
31:24
Read / Write Ignored
Performance Monitor Identification (ID) -
IXP45X/IXP46X network processors = 0x14
23:4
Read-unpredictable / Write-as-0
Reserved
3
Read / Write
Clock Counter Divider (D) -
0 = CCNT counts every processor clock cycle
1 = CCNT counts every 64
th
processor clock cycle
2
Read-unpredictable / Write
Clock Counter Reset (C) -
0 = no action
1 = reset the clock counter to ‘0x0’
1
Read-unpredictable / Write
Performance Counter Reset (P) -
0 = no action
1 = reset all performance counters to ‘0x0’
0
Read / Write
Enable (E) -
0 = all counters are disabled
1 = all counters are enabled
Table 60.
Interrupt Enable Register (Sheet 1 of 2)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
P
3
P
2
P
1
P
0 C
reset value: [4:0] = 0b00000, others unpredictable
Bits
Access
Description
31:5
Read-unpredictable / Write-as-0
Reserved
4
Read / Write
PMN3 Interrupt Enable (P3) -
0 = disable interrupt
1 = enable interrupt
3
Read / Write
PMN2 Interrupt Enable (P2) -
0 = disable interrupt
1 = enable interrupt