Intel 81342 Developer's Manual page 600

T h e w a v e f o r m i n
F i g u r e 8 8 . 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 ( c o n t r o l l e d w i t h s o f t w a r e )
VDDQ
(System*)
VREF
Command
A0-A9, A11
BA0, BA1
Notes:
VTT is not applied directly to the device, however t
*
** t
MRD
can be applied.
The two Autorefresh commands may be moved to follow the first MRS, but precede the second Precharge All
command.
W h e n t h e D D R S D R A M s u b s y s t e m i m p l e m e n t s E C C (
C o r r e c t i o n a n d D e t e c t i o n " o n p a g e 6 0 7
m e m o r y a r r a y w i t h t h e 8 1 3 4 1 a n d 8 1 3 4 2 . I t i s i m p o r t a n t t h a t e v e r y m e m o r y l o c a t i o n h a s
a v a l i d E C C b y t e . T h e A p p l i c a t i o n D M A i n c l u d e s a m e m o r y b l o c k f i l l m o d e w h i c h c a n b e
u s e d t o f i l l t h e m e m o r y a r r a y w i t h a c o n s t a n t (
O p e r a t i o n " o n p a g e 5 0 5
s m a l l p o r t i o n o f m e m o r y m u s t b e i n i t i a l i z e d b y t h e I n t e l X S c a l e
s o f t w a r e t o s t o r e t h e A D M A d e s c r i p t o r . W h e n t h e m e m o r y a r r a y i s n o t i n i t i a l i z e d , t h e
m i c r o a r c h i t e c t u r e m a y a t t e m p t t o r e a d m e m o r y l o c a t i o n s b e y o n d t h e s p e c i f i e d w o r d ( s ) .
I n t h i s c a s e , t h e D M C U r e p o r t s a n E C C e r r o r e v e n t h o u g h s o f t w a r e d i d n o t s p e c i f i c a l l y
r e q u e s t t h e u n - i n i t i a l i z e d d a t a .
®
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
6 0 0
F i g u r e 8 8 i l l u s t r a t e s 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 .
VDD
t
VTD
VTT
t
200µs
LVCMOS Low Level
CK
CK#
t
IS
CKE
t
IS
NOP
DM
t
A10
High-Z
DQS
High-Z
DQ
Power-up: Extended Mode
VDD and CK stable
is required before any command can be applied and 200 cycles of CK are required before a Read command
= Don't Care
) , t h e r e b y i n i t i a l i z i n g t h e a s s o c i a t e d E C C b y t e s i n t h e p r o c e s s . A
®
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
t
CK
CH
t t
MRD MRD
t
CL
t
IH
t
IH
PRE EMRS MRS PRE
t
IH
t
IS
CODE CODE
t
t
IH
IH
t
IS
IS
CODE CODE
All Banks All Banks
t
IH
t
IS
BA0= BA0=
H L
BA1=L BA1=L
Load Mode
Register Set Register, Reset DLL
must be greater than or equal to zero to avoid device latchup.
VTD
S e c t i o n 7 . 3 . 4 , " D D R E r r o r
) , t h e n i n i t i a l i z a t i o n s o f t w a r e i n i t i a l i z e s t h e e n t i r e
S e c t i o n 5 . 7 . 8 , " M e m o r y B l o c k F i l l
200 cycles of CK**
t t t t
RP RFC RFC MRD
AR AR MRS ACT
CODE RA
t
IH
t
IS
CODE RA
BA0=
RA
L
BA1=L
Load Mode
Register
(with A8=L)
A7798-01
®
m i c r o a r c h i t e c t u r e
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