Table E–11: 21164/21164PC Read Counters for OpenVMS Alpha and DIGITAL UNIX

Bits Meaning When Returned

63:48 Counter 0 returned value

47:32 Counter 1 returned value

31:30 MBZ

29:16 Counter 2 returned value

15:1 MBZ

0

Set means success; clear means failure

Table E–12: 21164/21164PC Write Counters for OpenVMS Alpha and DIGITAL UNIX

Bits Meaning

63:48 Counter 0 written value

47:32 Counter 1 written value

31:30 MBZ

29:16 Counter 2 written value

15:0 MBZ

Table E–13: 21164/21164PC Counter 1 (PCSEL1) Event Selection

The following values choose the counter 1 (PCSEL1) event selection:

Value Meaning

0Nothing issued, pipeline frozen

1Some but not all issuable instructions issued

2Nothing issued, pipeline dry

3Replay traps (ldu, wb/maf, litmus test)

4Single issue cycles

5Dual issue cycles

6Triple issue cycles

7Quad issue cycles

8Flow change (all branches, jsr-ret, hw_rei), where:

If PCSEL2 has value 3, flow change is a conditional branch

If PCSEL2 has value 2, flow change is a JSR-RET

Waivers and Implementation-Dependent Functionality E–19

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Image 347
Compaq ECQD2KCTE manual Table E-13 21164/21164PC Counter 1 PCSEL1 Event Selection