Preliminary
VG37648041AT
256M:x4, x8, x16
VIS
CMOS Synchronous Dynamic RAM
EXTENDED MODE REGISTER
The Extended Mode Resister is used to enable or disable the DLL of the DDR SDRAM, as shown in Figure
3. The Extended Mode Register is programmed via the LOAD MODE REGISTER command (with BA0=1 and
BA1=0) and will retain the stored information until it is programmed again or the device loses power.
The Extended Mode Register must be loaded when all banks are idle, and the controller must wait the spec-
ified time before initiating the subsequent operation. Voolating either of these requirements will result in
unspecified operaiton.
Address Bus
BA0 BA1 A12
A9
A6
A11 A10
A8 A7
A4 A3
A0
A5
A2 A1
2
0
1
14
9
6
4
5
3
8
7
13 12 11 10
0*
Extended Mode Register (Ex)
1*
Operating Mode
DLL
* E13 and E12 (BA0 and BA1)
must be 1,0 to select the
Extended Mode Register (vs. the
base Mode Register).
E0
0
DLL
Enable
Disable
1
E12 E11 E10 E9
E8
0
E7
0
E6
0
E5
0
E4
0
E3
0
E2
0
E1
0
E0
Operating Mode
Normal Operation
0
-
0
-
0
-
0
-
Valid
-
-
-
-
-
-
-
-
-
All other stateds reserved
Figure 3
EXTENDED MODE REGISTER DEFINITION
Document : 1G5-0157
Rev.1
Page15
VML [ VANGUARD INTERNATIONAL SEMICONDUCTOR ]
