ii
ii
i
PEMPEM
PEMPEM
PEM
2.4G2.4G
2.4G2.4G
2.4G
b SDRAM-DDRb SDRAM-DDR
b SDRAM-DDRb SDRAM-DDR
b SDRAM-DDR
AS4DDR32M72PBG
AS4DDR32M72PBG
Rev. 1.2 06/09
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
7
Austin Semiconductor, Inc.
OPERATING MODE
The normal operating mode is selected by issuing a MODE
REGISTER SET command with bits A7-A12 each set to zero,
and bits A0-A6 set to the desired values. A DLL reset is initiated
by issuing a MODE REGISTER SET command with bits A7 and
A9-A12 each set to zero, bit A8 set to one, and bits A0-A6 set to
the desired values. Although not required, JEDEC specifications
recommend when a LOAD MODE REGISTER command is
issued to reset the DLL, it should always be followed by a
LOAD MODE REGISTER command to select normal operating
mode.
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 versions 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, output drive strength, and QFC#. These
functions are controlled via the bits shown in Figure 3. The
extended mode register is programmed via the LOAD MODE
REGISTER 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 register (BA0/BA1 both LOW)
to reset the DLL.
The extended mode register must be loaded when all 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 operation.
BA
1
BA
0
A
12
A
11
A
10
A
9
A
8
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
Address Bus
Burst LengthBT
Operating Mode
(BA0 and BA1 must be
"0, 0" to select
the base mode register
(vs. the extended
0*
0*
CAS Latency
* M14 and M13
mode register).
Mode Register (Mx)
M2
M1
M0
M3 = 0 M3 = 1
0
0
0
Reserved
Reserved
0
0
1
2 2
0
1
0
4 4
0
1
1
8 8
1
0
0
Reserved
Reserved
1
0
1
Reserved Reserved
1
1
0
Reserved
Reserved
1
1
1
Reserved
Reserved
Burst Length
0
1
Sequential
Interleaved
M3
Burst Type
CAS Latency
M6
M5 M4
Reserved
0
00
Reserved
0
0
1
2
0
1
0
Reserved
0
1
1
Reserved
1
0
0
Reserved
1
0
1
2.5
1
1
0
Reserved
1
1
1
M12
M11
M10
M9
M8
M7 M6-M0
Operating Mode
0
0
0
0
0 0 Valid
Normal Operation
0
0
0
0
1 0
idVal
Normal Operation/Reset DLL
-
-
-
-
--
-
All other states reserved
FIGURE 1 - MODE BURST DEFINITION