TABLE F-2MMU Trap Types, Causes, and Stored State Register Update Policy

 

 

 

 

 

Registers Updated

 

 

 

 

 

(Stored State in MMU)

 

 

 

 

 

I-MMU

 

D-MMU

 

 

 

 

 

Tag

D-SFSR,

Tag

 

Ref #Trap Name

Trap Cause

I-SFSR

Access

SFAR

Access

Trap Type

 

 

 

 

 

 

 

 

2.

instruction_access_exception

Several (see below)

X2

X

 

 

0816

3.

fast_data_access_MMU_miss

D-TLB miss

 

 

X3

X

6816–6B16

4.

data_access_exception

Several (see below)

 

 

X3

X1

3016

5.

fast_data_access_protection

Protection violation

 

 

X3

X

6C16-6F16

6.

privileged_action

Use of privileged ASI

 

 

X3

 

3716

7.

watchpoint

Watchpoint hit

 

 

X3

 

6116–6216

8.

mem_address_not_aligned,

Misaligned memory

 

 

(impl.

 

3516, 3616,

 

*_mem_address_not_aligned

operation

 

 

dep

 

3816, 3916

 

 

 

 

 

#237)

 

 

9.

instruction_access_error

Several (see below)

X2

 

 

 

0A16

10

data_access_error

Several (see below)

 

 

X3

 

3216

X1: The contents of the context field of the D-MMU Tag Access Register are undefined after a data_access_exception.

X2: I-SFSRis updated according to its update policy described in Section F.10.9

X3: D-SFSRand D-SFARare updated according to the update policy described in Section F.10.9

The traps with Ref #1~8 in TABLE F-2conform to the specification defined in Section F.5 of Commonality.

The additional traps (Ref #9 and #10) are described below.

Ref 9: instruction_access_error — Signalled upon detection of at least one of the following errors.

An uncorrectable error is detected upon an instruction fetch reference.

A bus error response from the UPA bus is detected upon an instruction fetch reference.

mITLB (sITLB and fITLB) multiple hits are detected in a mITLB lookup for an instruction reference.

An fITLB entry parity error is detected in an fTLB lookup for an instruction reference.

Ref 10: data_access_error — Signalled upon the detection of at least one of the following errors.

An uncorrectable error is detected upon an instruction operand access.

A bus error response from the UPA bus is detected upon an operand access.

mDTLB (sDTLB and fDTLB) multiple hits are detected in an mDTLB lookup for an operand access.

90 SPARC JPS1 Implementation Supplement: Fujitsu SPARC64 V • Release 1.0, 1 July 2002

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Fujitsu Fujitsu SPARC64 V manual Instructionaccessexception