Intel 81342 Developer's Manual page 83

A d d r e s s T r a n s l a t i o n U n i t ( P C I - X ) — I n t e l
2 . 3 B i g E n d i a n B y t e S w a p p i n g
E a c h m e m o r y a n d I / O w i n d o w h a s a n a s s o c i a t e d b y t e s w a p p i n g e n a b l e l o c a t e d i n t h e
f o l l o w i n g a d d r e s s t r a n s l a t i o n r e g i s t e r s :
• b i t 0 o f I n b o u n d A d d r e s s T r a n s l a t e V a l u e R e g i s t e r 0 - 3 ( I A T V R 0 - 3 )
• b i t 0 o f I n b o u n d E x p a n s i o n R O M T r a n s l a t e V a l u e R e g i s t e r ( E R T V R )
• b i t 0 o f O u t b o u n d I / O W i n d o w T r a n s l a t e V a l u e R e g i s t e r ( O I O W T V R )
• b i t 2 7 o f O u t b o u n d U p p e r M e m o r y B A R 0 - 3 ( O U M B A R 0 - 3 )
N o t e : T h e M e s s a g i n g U n i t ( M U ) M e m o r y i s m a p p e d i n P C I W i n d o w 0 ( A T U B a s e A d d r e s s
R e g i s t e r 0 ) a l o n g w i t h t h e M S I - X t a b l e s t r u c t u r e s . B y t e s w a p p i n g s h o u l d n o t b e e n a b l e d
f o r B A R 0 w h e n u s i n g M S I - X .
2 . 3 . 1 I n b o u n d B y t e S w a p p i n g
W h e n e n a b l e d , t h e s w a p p i n g o c c u r s a s d e s c r i b e d i n
f o r 3 2 - b i t P C I " o n p a g e 8 3
p a g e 8 3 . T h e b y t e s a r e s w a p p e d w i t h i n a D W O R D a n d b y t e s w a p p i n g i s p e r f o r m e d f o r
a l l t r a n s a c t i o n s r e g a r d l e s s o f b y t e c o u n t .
F i g u r e 9 . I n b o u n d B y t e S w a p p i n g f o r 3 2 - b i t P C I
Byte 0 Byte 0
W ord 0 [31:24]
W ord 0 [7:0]
F i g u r e 1 0 . I n b o u n d B y t e S w a p p i n g f o r 6 4 - b i t P C I
Word 1 [31:24] Byte A Byte A
Word 1 [7:0]
+7
D e c e m b e r 2 0 0 7
O r d e r N u m b e r : 3 1 5 0 3 7 - 0 0 2 U S
®
8 1 3 4 1 a n d 8 1 3 4 2
a n d F i g u r e 1 0 , " I n b o u n d B y t e S w a p p i n g f o r 6 4 - b i t P C I " o n
W ord 0 [23:16] W ord 0 [15:8]
W ord 0 [15:8] W ord 0 [23:16]
+3 +2
Word 1 [23:16] Byte B Byte B Word 1 [15:8] Byte C Byte C Word 1 [7:0] Byte D Byte D
Word 1 [15:8] Word 1 [16:23] Word 1 [31:24]
+6 +5
F i g u r e 9 , " I n b o u n d B y t e S w a p p i n g
W ord 0 [7:0]
W ord 0 [31:24]
+1 +0
Word 0 [31:24] Word 0 [23:16]
Word 0 [7:0] Word 0 [15:8]
+4 +3 +2
32-Bit W ord on Internal Data Bus
32-Bit W ord on PCI Bus
B6189-01
Word 0 [15:8] Word 0 [7:0] Two 32-Bit Words on
Internal Data Bus
Word 0 [23:16] Word 0 [31:24] Two 32-Bit Words
on 64-Bit PCI Bus
+1 +0
®
I n t e l 8 1 3 4 1 a n d 8 1 3 4 2 I / O P r o c e s s o r s
D e v e l o p e r ' s M a n u a l
B6190-01
8 3