Intel 81342 Developer's Manual page 594

7 . 3 . 3 . 7 D D R S D R A M I n i t i a l i z a t i o n
S i n c e D D R S D R A M d e v i c e s c o n t a i n a c o n t r o l l e r w i t h i n t h e d e v i c e , t h e D M C U m u s t
i n i t i a l i z e t h e m s p e c i f i c a l l y . U p o n t h e d e a s s e r t i o n o f i n t e r n a l b u s r e s e t , s o f t w a r e
i n i t i a l i z e s t h e D D R S D R A M d e v i c e s w i t h t h e s e q u e n c e i l l u s t r a t e d w i t h
H o w e v e r , b e f o r e e x e c u t i n g t h e D D R S D R A M i n i t i a l i z a t i o n s e q u e n c e p r o v i d e d b e l o w ,
s o f t w a r e m u s t r e a d t h e S P D ( S e r i a l P r e s e n c e - D e t e c t ) d a t a a n d t h e n p r o g r a m t h e D M C U
p a r a m e t e r s a s e x p l a i n e d i n
p a g e 6 0 1
p a r a m e t e r s h a v e b e e n p r o g r a m m e d .
1 . T h e D M C U a p p l i e s t h e c l o c k (
( c l o c k f r e q u e n c y u n k n o w n ) .
2 . T h e D M C U m u s t s t a b i l i z e
3 . T h e D M C U h o l d s a l l t h e c o n t r o l i n p u t s i n a c t i v e (
1
) , p l a c e s a l l d a t a o u t p u t s a n d s t r o b e s i n t h e H i g h - Z s t a t e (
D Q S [ 8 : 0 ] #
s u p p l y v o l t a g e r e a c h e s t h e d e s i r e d l e v e l . A s s e r t i n g
4 . S o f t w a r e d i s a b l e s t h e r e f r e s h c o u n t e r b y s e t t i n g t h e R F R t o z e r o .
5 . S o f t w a r e i s s u e s o n e
a c c o m p l i s h e d b y s e t t i n g t h e S D I R t o 0 0 0 0 _ 0 0 7 0 H . T h e D M C U a s s e r t s
w i t h t h e N O P .
6 . S o f t w a r e i s s u e s a
t h e S D I R t o 0 0 0 2 _ 0 0 2 0 H .
7 . S o f t w a r e i s s u e s a n
0 1 0 0 _ 0 0 0 0 H t o t h e S D I R .
8 . S o f t w a r e i s s u e s a n
0 1 8 0 _ 0 0 0 0 H t o t h e S D I R .
9 . S o f t w a r e i s s u e s a n
b y w r i t i n g 0 0 8 0 _ 0 0 0 0 H t o S D I R . D M C U s u p p o r t s t h e f o l l o w i n g D D R a n d D D R 2
S D R A M m o d e p a r a m e t e r s :
a. DLL = Enable/Disable
b. Off-Chip Driver (OCD) Impedance Adjustment — applies to DDR2 SDRAM only.
c. Additive Latency (AL) is always zero for 81341 and 81342.
F i g u r e 8 6 . S u p p o r t e d D D R 2 S D R A M E x t e n d e d M o d e R e g i s t e r S e t t i n g s
T h e D D R S D R A M E x t e n d e d
M o d e R e g i s t e r r e s i d e s i n
t h e D D R S D R A M d e v i c e s .
B A [ 1 : 0 ] m u s t b e 0 1
®
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
5 9 4
S e c t i o n 7 . 3 . 3 . 8 , " D D R S D R A M M o d e P r o g r a m m i n g " o n
. T h e D M C U d o e s i n t e r a c t p r o p e r l y w i t h t h e D D R S D R A M u n t i l t h e s e
n o t
M _ C K [ 2 : 0 ]
D Q [ 7 1 : 0 ]
, ) , a n d d e a s s e r t s
NOP
c y c l e a f t e r t h e 2 0 0 u s d e v i c e d e s e l e c t . A
precharge-all
extended-mode-register-set
extended-mode-register-set
extended-mode-register-set 1 (EMRS(1) )
A 1 2 A 1 0 A 9
0 0 0
O C D O p e r a t i o n
t o s e l e c t t h e E x t e n d e d M o d e R e g i s t e r .
2
®
I n t e l 8 1 3 4 1 a n d 8 1 3 4 2 — D D R S D R A M M e m o r y C o n t r o l l e r
M _ C K [ 2 : 0 ] ) a t p o w e r u p a l o n g w i t h s y s t e m p o w e r
w i t h i n 1 0 0 s a f t e r p o w e r s t a b i l i z e s .
R A S #
C K E [ 1 : 0 ]
f o r a m i n i m u m o f 2 0 0 u s a f t e r
P _ R S T #
c o m m a n d t o t h e D D R S D R A M i n t e r f a c e b y s e t t i n g
2 ( E M R S ( 2 ) )
3 ( E M R S ( 3 ) )
A 7 A 6
0 0
A d d i t i v e L a t e n c y
F i g u r e 8 8 .
C A S # W E # S C E [ 1 : 0 ] # =
, , ,
D Q S [ 8 : 0 ]
,
a c h i e v e s t h i s s t a t e .
NOP
i s
C K E [ 1 : 0 ]
c o m m a n d b y w r i t i n g
c o m m a n d b y w r i t i n g
c o m m a n d t o e n a b l e D L L
A 3 A 0
0
D L L E n a b l e :
0 = E n a b l e
1 = D i s a b l e
R T T
O u t p u t D r i v e S t r e n g t h
B 6 2 6 0 - 0 1
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