Fujitsu Fujitsu SPARC64 V manual Invalid Valid

Models: Fujitsu SPARC64 V

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4.The block store with commit instruction always stores the operand in main storage and invalidates the line in the L1D cache if it is present. The invalidation is performed through an S_INV_REQ transaction through UPA by the system controller.

5.The block store instruction stores the operand into main storage if it is not present in the operand cache and the status of the line is invalid, shared, or owned. In case the line is not present in the L1D cache and is exclusive or modified on the L2 cache, the block store instruction modifies only the line in L2 cache. If the line is present in the operand cache and the status is either clean/shared or clean/ owned, the line is stored in main storage. If the line is present in the operand cache and the status is clean/exclusive, the line in the operand cache is invalidated and the operand is stored in the L2 cache. If the line is in the operand cache and the status is modified/modified, the operand is stored in the operand cache. The following table summarizes each cache status before block store and the results of the block store. Blank cells mean that no action occurred in the corresponding cache or memory, and the data, if it exists, is unchanged.

 

Storage

 

 

Status

 

 

 

 

 

 

 

 

 

Cache status

L1

 

Invalid

 

Valid

 

before bst

L2

E, M

I, S, O

E

M

S, O

 

 

 

 

 

 

 

 

L1

invalidate

Action

L2

update

update

update

S

 

Memory

update

update

 

 

 

 

 

 

 

Exceptions fp_disabled PA_watchpoint VA_watchpoint

illegal_instruction (misaligned rd)

mem_address_not_aligned (see Block Load and Store ASIs on page 120) data_access_exception (see Block Load and Store ASIs on page 120) LDDF_mem_address_not_aligned (see Block Load and Store ASIs on page 120) data_access_error

fast_data_access_MMU_miss fast_data_access_protection

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

Page 59
Image 59
Fujitsu Fujitsu SPARC64 V manual Invalid Valid