beautypg.com

A.42 partial store (vis i), A.49 prefetch data, Partial store (vis i) 57 prefetch data 57 – FUJITSU Implementation Supplement Fujitsu SPARC64 V User Manual

Page 68

background image

Release 1.0, 1 July 2002

F. Chapter A

Instruction Definitions: SPARC64 V Extensions

57

A.42

Partial Store (VIS I)

Please refer A.42 in Commonality for general details.

Watchpoint exceptions on partial store instructions occur conservatively on
SPARC64 V. The

DCUCR

Data Watchpoint masks are only checked for nonzero value

(watchpoint enabled). The byte store mask (

r[rs2]

) in the partial store instruction

is ignored, and a watchpoint exception can occur even if the mask is zero (that is, no
store will take place) (impl. dep. #249).

For a partial store instruction with mask = 0, SPARC64 V still issues a UPA
transaction with zero-byte mask.

Exceptions:

fp_disabled
PA_watchpoint
VA_watchpoint
illegal_instruction

(misaligned rd)

mem_address_not_aligned

(see Partial Store ASIs on page 120)

data_access_exception

(see Partial Store ASIs on page 120)

LDDF_mem_address_not_aligned

(see Partial Store ASIs on page 120)

data_access_error
fast_data_access_MMU_miss
fast_data_access_protection

A.49

Prefetch Data

Please refer to Section A.49, Prefetch Data, of

Commonality

for principal information.

The

prefetcha

instruction of SPARC64 V works for the following ASIs.

ASI_PRIMARY

(080

16

),

ASI_PRIMARY_LITTLE

(088

16

)

ASI_SECONDARY

(081

16

),

ASI_SECONDARY_LITTLE

(089

16

)

ASI_NUCLEUS

(04

16

),

ASI_NUCLEUS_LITTLE

(0C

16

)

ASI_PRIMARY_AS_IF_USER

(010

16

),

ASI_PRIMARY_AS_IF_USER_LITTLE

(018

16

)

ASI_SECONDARY_AS_IF_USER

(011

16

),

ASI_SECONDARY_AS_IF_USER_LITTLE

( 019

16

)

If an ASI other than the above is specified,

prefetcha

is executed as a nop.