Compaq EV68A specifications ProfileMe PC Register Pmpc, Exception Address Register Excaddr, Pal

Models: EV68A

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5.2.6 ProfileMe PC Register – PMPC

The ProfileMe PC register (PMPC) is a read-only register that contains the PC of the last profiled instruction. Additional information is available in the I_STAT and PCTR_CTL register descriptions.

Usage of PMPC in performance monitoring is described in Section 6.10.

Figure 5–11shows the ProfileMe PC register.

Figure 5–11 ProfileMe PC Register

63

2

1

0

PC[63:2]

PAL

LK99-0018A

Table 5–4describes the ProfileMe PC register fields.

Table 5–4 ProfileMe PC Fields Description

Name

Extent

Type

Description

 

 

 

 

PC[63:2]

[63:2]

RO

Address of the profiled instruction

Reserved

[1]

RO

Read as zero

PAL

[0]

RO

Indicates that the PC field contains a physical-mode PALmode

 

 

 

address

 

 

 

 

5.2.7 Exception Address Register – EXC_ADDR

The exception address register (EXC_ADDR) is a read-only register that is updated by hardware when it encounters an exception or interrupt.

EXC_ADDR[0] is set if the associated exception occurred in PALmode. The exception actions are listed here:

If the exception was a fault or a synchronous trap, EXC_ADDR contains the PC of the instruction that triggered the fault or trap.

If the exception was an interrupt, EXC_ADDR contains the PC of the next instruc- tion that would have executed if the interrupt had not occurred.

Figure 5–12shows the exception address register.

Figure 5–12 Exception Address Register

63

2

1

0

PC[63:2]

PAL

LK99-0018A

5–8

Internal Processor Registers

21264/EV68A Hardware Reference Manual

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Compaq EV68A ProfileMe PC Register Pmpc, Exception Address Register Excaddr, 4describes the ProfileMe PC register fields