mt18vddt12872ag-335 Micron Semiconductor Products, mt18vddt12872ag-335 Datasheet - Page 10

• Manufacturer Part Number: mt18vddt12872ag-335
• Description: 256mb, 512mb, 1gb, 2gb X72, Ecc, Dr 184-pin Ddr Sdram Udimm
• Manufacturer: Micron Semiconductor Products

register is programmed via the LOAD MODE REGIS-
TER command to the mode register (with BA0 = 1 and
BA1 = 0) and will retain the stored information until it
is programmed again or the device loses power. The
enabling of the DLL should always be followed by a
LOAD MODE REGISTER command to the mode regis-
ter (BA0/BA1 both LOW) to reset the DLL.
all device banks are idle and no bursts are in progress,
and the controller must wait the specified time before
initiating any subsequent operation. Violating either
of these requirements could result in unspecified oper-
ation.
DLL Enable/Disable
DLL enable is required during power-up initialization
and upon returning to normal operation after having
disabled the DLL for the purpose of debug or evalua-
tion. (When the device exits self refresh mode, the DLL
is enabled automatically.) Any time the DLL is enabled,
200 clock cycles must occur before a READ command
can be issued.
pdf: 09005aef80814e61, source: 09005aef807f8acb
DD18C32_64_128_256x72AG.fm - Rev. B 9/04 EN
The extended mode register must be loaded when
The DLL must be enabled for normal operation.
256MB, 512MB, 1GB, 2GB (x72, ECC, DR)
10
256MB Module
512MB and 1GB Modules
2GB Module
NOTE:
E13
1. BA1 and BA0 (E13 and E12 for 256MB, E14 and E13 for
2. The QFC# option is not supported.
0
0
–
15
BA1 BA0
1
512MB, 1GB, or E15 and E14 for 2GB) must be “0, 1” to
select the Extended Mode Register (vs. the base Mode
Register).
Figure 6: Extended Mode Register
E12
0 1
1
14
BA1 BA0
0
–
14
1
Micron Technology, Inc., reserves the right to change products or specifications without notice.
0 1
1 1
184-PIN DDR SDRAM UDIMM
13
E11
BA1 BA0
13
13
0
–
A13
1 1
12
12
E10
A12
12
A12
0
–
11
11
A11
A11
11
E9
0
A11
–
Definition Diagram
10
10
A10
10
E8
A10
0
–
A10
Operating Mode
Operating Mode
E7
9
9
0
–
A9
A9
9
Operating Mode
A9
E6 E5
0
–
8
8
A8
A8
8
A8
0
–
7
7
A7 A6 A5 A4 A3
7
A7 A6 A5 A4 A3
A7 A6 A5 A4 A3
E4
0
–
6
6
6
E3
0
–
5
5
5
©2004 Micron Technology, Inc. All rights reserved.
E2
0
–
4
4
4
3
3
3
E1,
Valid
–
2
2
A2 A1 A0
2
E0
A2 A1 A0
A2 A1 A0
DS
DS
DS
1
1
1
E1
DLL
DLL
0
DLL
0
0
Operating Mode
Reserved
Reserved
0
E0
0
1
Extended Mode
Register (Ex)
Extended Mode
Register (Ex)
Drive Strength
Extended Mode
Register (Ex)
Address Bus
Address Bus
Address Bus
Normal
Disable
Enable
DLL