March 2002 Release
735
Virtex-II Pro™ Platform FPGA Documentation
1-800-255-7778
Alphabetical Instruction Listing
R
stwbrx
Store Word Byte-Reverse Indexed
Description
An effective address (EA) is calculated by adding an index to a base address, which are
formed as follows:
•
The contents of register
r
B are used as the index.
•
If the
r
A field is 0, the base address is 0.
•
If the
r
A field is not 0, the contents of register
r
A are used as the base address.
The least-significant halfword of register
r
S is byte-reversed and stored into the halfword
referenced by EA as follows:
•
r
S[24:31] are stored into the byte referenced by EA.
•
r
S[16:23] are stored into the byte referenced by EA
+
1.
•
r
S[8:15] are stored into the byte referenced by EA
+
2.
•
r
S[0:7] are stored into the byte referenced by EA
+
3.
Pseudocode
EA
←
(
r
A|0) + (
r
B)
MS(EA, 4)
←
(
r
S)
24:31
||
(
r
S)
16:23
||
(
r
S)
8:15
||
(
r
S)
0:7
Registers Altered
•
None.
Exceptions
•
Data storage—if the access is prevented by zone protection when data relocation is
enabled.
-
No-access-allowed zone protection applies only to accesses in user mode.
-
Read-only zone protection applies to user and privileged modes.
•
Data TLB miss—if data relocation is enabled and a valid translation-entry
corresponding to the EA is not found in the TLB.
Execution of any of the following invalid-instruction forms results in a boundedly-
undefined result rather than a program exception:
•
Reserved bits containing a non-zero value.
stwbrx
r
S
,
r
A,
r
B
X Instruction Form
31
r
S
r
A
r
B
662
0
0
6
1
1
1
6
2
1
3
1
Содержание Virtex-II Pro PPC405
Страница 1: ...R Volume 2 a PPC405 User Manual Virtex II Pro Platform FPGA Developer s Kit March 2002 Release...
Страница 14: ...322 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation Preface R...
Страница 252: ...560 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...
Страница 260: ...568 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...
Страница 562: ...870 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...