
W972GG6JB
7.2.2.2
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 the DLL disabled. The DLL is automatically
disabled when entering Self Refresh operation and is automatically re-enabled and reset upon exit of
Self Refresh operation. Any time the DLL is enabled (and subsequently reset), 200 clock cycles must
occur before a Read command can be issued to allow time for the internal clock to be synchronized
with the external clock. Failing to wait for synchronization to occur may result in a violation of the t AC
or t DQSCK parameters.
BA2
BA1
BA0
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
Address Field
0
0
1
0
Qoff
0* 1
DQS
OCD program
Rtt
WR BT
Additive Latency
Rtt
D.I.C
DLL
Extended Mode Register (1)
BA1
0
0
1
1
BA0
0
1
0
1
MRS mode
MRS
EMR (1)
EMR (2)
EMR (3)
A6
0
0
1
1
A2
0
1
0
1
Rtt (nominal)
ODT disabled
75 ohm
150 ohm
50 ohm* 2
A0
0
1
DLL Enable
Enable
Disable
Driver impedance adjustment
A9
0
A8
0
A7
0
OCD Calibration Program
OCD calibration mode exit; matain setting
0
0
1
Drive (1)
Additive Latency
0
1
1
1
0
1
0
0
1
Drive (0)
Adjust mode* 3
OCD Calibration default* 4
A5
0
0
A4
0
0
A3
0
1
Latency
0
1
0
1
0
2
A12
0
1
A10
Qoff (Optional)* 5
Output buffer enabled
Output buffer disabled
DQS
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
3
4
5
6
Reserved
0
Enable
1
Disable
Output Driver Impedance Control
A10
(DQS Enable)
Strobe Function Matrix
DQS DQS
A1
Output driver
impedance control
Driver
size
0
(Enable)
DQS
DQS
0
Normal
100%
1 (Disable)
DQS
Hi-z
1
Reduced
60%
Notes:
1. A11 default is “ 0 ” RDQS disabled.
2. Optional for DDR2-667, mandatory for DDR2-800 and DDR2-1066.
3. When Adjust mode is issued, AL from previously set value must be applied.
4. After setting to default, OCD calibration mode needs to be exited by setting A9-A7 to 000. Refer to the section 7.2.3 for
detailed information.
5. Output disabled - DQs, LDQS, LDQS , UDQS, UDQS . This feature is used in conjunction with DIMM I DD measurements
when I DDQ is not desired to be included.
Figure 3 – EMR (1)
Publication Release Date: Nov. 29, 2011
- 12 -
Revision A02