Compaq 21264 12describes the Ibox status register fields, Ibox Status Register Fields Description

Models: 21264 EV67

1 356
Download 356 pages 49.13 Kb
Page 161
Image 161

Ibox IPRs

Figure 5–23 Ibox Status Register

63

41 40 39 38 37

34 33 32

30 29 28

0

 

 

 

 

 

 

 

MIS

TRP

LS0

TRAP TYPE[3:0]

ICM

OVR[2:0]

PAR

 

LK99-0031A

 

Table 5–12describes the Ibox status register fields.

Table 5–12 Ibox Status Register Fields Description

Name

Extent

Type

Description

 

 

 

 

Reserved

[63:41]

RO

Reserved for Compaq.

MIS

[40]

RO

ProfileMe Mispredict Trap.

 

 

 

If the I_STAT[TRP] bit is set, this bit indicates that the profiled instruc-

 

 

 

tion caused a mispredict trap. JSR/JMP/RET/COR or HW_JSR/

 

 

 

HW_JMP/HW_RET/HW_COR mispredicts do not set this bit but can be

 

 

 

recognized by the presence of one of these instructions at the PMPC loca-

 

 

 

tion with the I_STAT[TRP] bit set. This identification is exact in all cases

 

 

 

except error condition traps. Hardware corrected Icache parity or Dcache

 

 

 

ECC errors, and machine check traps can occur on any instruction in the

 

 

 

pipeline.

TRP

[39]

RO

ProfileMe Trap.

 

 

 

This bit indicates that the profiled instruction caused a trap. The trap type

 

 

 

field, PMPC register, and instruction at the PMPC location are needed to

 

 

 

distinguish all trap types.

LS0

[38]

RO

ProfileMe Load-Store Order Trap.

 

 

 

If the profiled instruction caused a replay trap, this bit indicates that the

precise trap cause was an Mbox load-store order replay trap.

If clear, this bit indicates that the replay trap was any one of the follow- ing:

Mbox load-load order Mbox load queue full Mbox store queue full

Mbox wrong size trap (such as, STL LDQ)

Mbox Bcache alias (2 physical addresses map to same Bcache line) Mbox Dcache alias (2 physical addresses map to same Dcache line) Icache parity error

Dcache ECC error

Alpha 21264/EV67 Hardware Reference Manual

Internal Processor Registers 5–19

Page 161
Image 161
Compaq 21264, EV67 12describes the Ibox status register fields, Ibox Status Register Fields Description, Mis, Trp, LS0