Table E–23:

21264 Select Desired Events for OpenVMS Alpha and DIGITAL

 

UNIX

 

 

 

 

R17/a1 Bits

Meaning

 

 

 

 

4

Bit value

Meaning

 

1

Counter 0 counts retired instructions.

 

0

Counter 0 counts cycles.

3–2

Bit value

Meaning

 

0000

Counter 1 counts cycles.

 

0001

Counter 1 counts retired conditional branches.

 

0010

Counter 1 counts retired branch mispredicts.

 

0011

Counter 1 counts retired DTB single misses * 2.

 

0100

Counter 1 counts retired DTB double double misses.

 

0101

Counter 1 counts retired ITB misses.

 

0110

Counter 1 counts retired unaligned traps.

 

0111

Counter 1 counts replay traps.

 

 

 

Table E–24: 21264 Read Counters for OpenVMS Alpha and DIGITAL UNIX

R0/v0 Bits

Meaning When Returned

 

 

63–48

Reserved

47–28

Counter 0 returned value

27–26

Reserved

25–6

Counter 1 returned value

5–0

Reserved

 

 

Table E–25: 21264 Write Counters for OpenVMS Alpha and DIGITAL UNIX

R17/a1 Bits

Meaning

 

 

63–48

Reserved

47–28

Counter 0 value to write

27–26

Reserved

25–6

Counter 1 value to write

 

 

E–28Alpha Architecture Handbook

Page 356
Image 356
Compaq ECQD2KCTE manual R17/a1 Bits Meaning