W9725G8JB Datasheet, PDF (1/86 Pages) Winbond – 8M  4 BANKS  8 BIT DDR2 SDRAM

W9725G8JB
8M  4 BANKS  8 BIT DDR2 SDRAM
Table of Contents-
1.
GENERAL DESCRIPTION ...................................................................................................................4
2.
FEATURES ...........................................................................................................................................4
3.
KEY PARAMETERS .............................................................................................................................5
4.
BALL CONFIGURATION ......................................................................................................................6
5.
BALL DESCRIPTION............................................................................................................................7
6.
BLOCK DIAGRAM ................................................................................................................................8
7.
FUNCTIONAL DESCRIPTION..............................................................................................................9
7.1 Power-up and Initialization Sequence ...................................................................................................9
7.2 Mode Register and Extended Mode Registers Operation ...................................................................10
7.2.1
Mode Register Set Command (MRS)...............................................................................10
7.2.2
Extend Mode Register Set Commands (EMRS) ..............................................................11
7.2.2.1
Extend Mode Register Set Command (1), EMR (1)................................................11
7.2.2.2
DLL Enable/Disable................................................................................................12
7.2.2.3
Extend Mode Register Set Command (2), EMR (2)................................................13
7.2.2.4
Extend Mode Register Set Command (3), EMR (3)................................................14
7.2.3
Off-Chip Driver (OCD) Impedance Adjustment ................................................................15
7.2.3.1
Extended Mode Register for OCD Impedance Adjustment ....................................16
7.2.3.2
OCD Impedance Adjust..........................................................................................16
7.2.3.3
Drive Mode .............................................................................................................17
7.2.4
On-Die Termination (ODT)...............................................................................................18
7.2.5
ODT related timings .........................................................................................................18
7.2.5.1
MRS command to ODT update delay.....................................................................18
7.3 Command Function.............................................................................................................................20
7.3.1
Bank Activate Command..................................................................................................20
7.3.2
Read Command ...............................................................................................................20
7.3.3
Write Command ...............................................................................................................21
7.3.4
Burst Read with Auto-precharge Command.....................................................................21
7.3.5
Burst Write with Auto-precharge Command.....................................................................21
7.3.6
Precharge All Command ..................................................................................................21
7.3.7
Self Refresh Entry Command ..........................................................................................21
7.3.8
Self Refresh Exit Command.............................................................................................22
7.3.9
Refresh Command ...........................................................................................................22
7.3.10
No-Operation Command ..................................................................................................23
7.3.11
Device Deselect Command..............................................................................................23
7.4 Read and Write access modes ...........................................................................................................23
7.4.1
Posted CAS ....................................................................................................................23
7.4.1.1
Examples of posted CAS operation......................................................................23
Publication Release Date: Oct. 12, 2010
-1-
Revision A01