MT36VDDF12872G Datasheet, PDF (13/37 Pages) Micron Technology – DDR SDRAM REGISTERED DIMM

All other combinations of values for A7–A12 are
reserved for future use and/or test modes. Test modes
and reserved states should not be used because
unknown operation or incompatibility with future ver-
sions may result.
Extended Mode Register
The extended mode register controls functions
beyond those controlled by the mode register; these
additional functions are DLL enable/disable and out-
put drive strength. These functions are controlled via
the bits shown in Figure 9, Extended Mode Register
Definition Diagram. The extended mode register is
programmed via the LOAD MODE REGISTER com-
mand to the mode register (with BA0 = 1 and BA1 = 0)
and will retain the stored information until it is pro-
grammed 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.
The extended mode register must be loaded when
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
The DLL must be enabled for normal operation.
DLL enable is required during power-up initialization
and upon returning to normal operation after having
1GB, 2GB (x72, ECC, DR)
184-PIN DDR RDIMM
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 with CKE HIGH must occur before a
READ command can be issued.
Figure 9: Extended Mode Register
Definition Diagram
BA1 BA0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 Address Bus
14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 _{Extended Mode}
01 11
Operating Mode
DS DLL Register (Ex)
E0
DLL
0
Enable
1
Disable
E1 Drive Strength
0
Normal
E12 E11 E10 E9 E8 E7 E6 E5 E4 E3 E2²
0 0 0 0 0 0 00 0 0 0
– – – – – – –– – – –
E1, E0
Valid
–
Operating Mode
Reserved
Reserved
NOTE:
1. BA1 and BA0 (E14 and E13) must be “0, 1” to select the
Extended Mode Register (vs. the base Mode Register).
2. QFC# is not supported.
pdf: 09005aef80772fd2, source: 09005aef8075ebf6
DDF36C128_256x72G.fm - Rev. D 9/04 EN
13
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