Vol. 3B 19-207

PERFORMANCE-MONITORING EVENTS

63H

BUS_LOCK_

CLOCKS

00H 

(Self)
20H 

(Any)

Number of clocks during which LOCK# is 

asserted on the external system bus.

3

Always counts in processor clocks.

60H

BUS_REQ_

OUTSTANDING

00H 

(Self)

Number of bus requests outstanding.
This counter is incremented by the number 

of cacheable read bus requests outstanding 

in any given cycle.

Counts only DCU full-line cacheable 

reads, not RFOs, writes, instruction 

fetches, or anything else. Counts 

“waiting for bus to complete” (last 

data chunk received).

65H

BUS_TRAN_BRD

00H 

(Self)
20H 

(Any)

Number of burst read transactions. 

66H

BUS_TRAN_RFO

00H 

(Self)
20H 

(Any)

Number of completed read for ownership 

transactions.

67H

BUS_TRANS_WB

00H 

(Self)
20H 

(Any)

Number of completed write back 

transactions.

68H

BUS_TRAN_

IFETCH

00H 

(Self)
20H 

(Any)

Number of completed instruction fetch 

transactions.

69H

BUS_TRAN_INVA

L

00H 

(Self)
20H 

(Any)

Number of completed invalidate 

transactions.

6AH

BUS_TRAN_PWR

00H 

(Self)
20H 

(Any)

Number of completed partial write 

transactions.

6BH

BUS_TRANS_P

00H 

(Self)
20H 

(Any)

Number of completed partial transactions.

6CH

BUS_TRANS_IO

00H 

(Self)
20H 

(Any)

Number of completed I/O transactions.

6DH

BUS_TRAN_DEF

00H 

(Self)
20H 

(Any)

Number of completed deferred transactions.

Table 19-37.  Events That Can Be Counted with the P6 Family Performance-Monitoring Counters (Contd.)

Unit

Event 

Num.

Mnemonic Event 

Name

Unit 

Mask Description

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