is43dr16320-3dbli Integrated Silicon Solution, Inc., is43dr16320-3dbli Datasheet - Page 12

• Manufacturer Part Number: is43dr16320-3dbli
• Description: 512mb X8, X16 Ddr2 Sdram
• Manufacturer: Integrated Silicon Solution, Inc.

or off using the ODT input signal. Before and after the EMRS is issued, the ODT input must be received with respect to the timings of
tAOFD, tMOD(max), tAOND; and the CKE input must be held HIGH throughout the duration of tMOD(max).
The DDR2 SDRAM supports the ODT on and off functionality in Active, Standby, and Power Down modes, but not in Self Refresh
mode. ODT timing diagrams follow for Active/Standby mode and Power Down mode.
IS43DR86400, IS43/46DR16320
required. The addressing is generated by the internal refresh controller. This makes the address bits a “Don’t Care” during a
REFRESH command.
SELF REFRESH
The SELF REFRESH command can be used to retain data in the DDR2 SDRAM, even if the rest of the system is powered down. When
in the self refresh mode, the DDR2 SDRAM retains data without external clocking. All power supply inputs (including VREF) must be
maintained at valid levels upon entry/exit and during SELF REFRESH operation.
The SELF REFRESH command is initiated like a REFRESH command except CKE is LOW. The DLL is automatically disabled upon
entering self refresh and is automatically enabled upon exiting self refresh.
ODT (On‐Die Termination)
The On‐Die Termination feature allows the DDR2 SDRAM to easily implement a termination resistance (Rtt) for each DQ, DQS, DQS#,
RDQS, and RDQS# signal. The ODT feature can be configured with the Extended Mode Register Set (EMRS) command, and turned on
EMRS to ODT Update Delay
ODT Timing for Active/Standby (Idle) Mode and Standard Active Power‐Down Mode
Notes:
1.
2.
3.
Integrated Silicon Solution, Inc. – www.issi.com –
Rev. 00A, 11/17/2009
Command
Internal Term.
Both ODT to Power Down Entry and Exit Latency timing parameter tANPD and tAXPD are met, therefore Non‐Power Down Mode timings have to be applied.
OD
ODT resistance is fully on. Both are measured from tAOND.
ODT turn off time min, tAOF(Min), is when the device starts to turn off the ODT resistance. ODT turn off time max, tAOF(Max) is when the bus is in high
impedance. Both are measured from tAOFD.
Resistance
ODT
CK#
T turn‐on time, tAON(Min) is when the device leaves high impedance and ODT resistance begins to turn on. ODT turn on time max, tAON(Max) is when the
CK
ODT
CKE
CK#
CK
tAOFD
~
~
~
Old Setting
tIS
~
~
~
~
EMRS
tMOD(Min)
0
tAXPD
1
NOP
VIH(AC)
tMOD(Max)
tIS
2
NOP
tAOND
3
tAON(Min)
VIL(AC)
tIS
NOP
4
tAON(Max)
5
tAOFD
ODT Ready
RTT
tIS
NOP
tANPD
tAOF(Min)
6
tAOND
~
~
~
NOP
tAOF(Max)
tIS
Updated
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