参数资料
型号: W9725G8JB-25I
厂商: WINBOND ELECTRONICS CORP
元件分类: DRAM
英文描述: DDR DRAM, PBGA84
封装: 8 X 12.50 MM, ROHS COMPLIANT, WBGA-84
文件页数: 10/86页
文件大小: 1462K
代理商: W9725G8JB-25I
W9725G8JB
Publication Release Date: Oct. 12, 2010
- 18 -
Revision A01
7.2.4
On-Die Termination (ODT)
On-Die Termination (ODT) is a new feature on DDR2 components that allows a DRAM to turn on/off
termination resistance for each DQ, DQS/ DQS , RDQS/ RDQS , and DM signal via the ODT control pin.
The ODT feature is designed to improve signal integrity of the memory channel by allowing the DRAM
controller to independently turn on/off termination resistance for any or all DRAM devices.
The ODT function can be used for all active and standby modes. ODT is turned off and not supported
in Self Refresh mode. (Example timing waveforms refer to 10.3, 10.4 ODT Timing for
Active/Standby/Power Down Mode and 10.5, 10.6 ODT timing mode switch at entering/exiting power
down mode diagram in Chapter 10)
DRAM
Input
Buffer
Input
Pin
VDDQ
sw1
Rval3
VDDQ
sw2
sw3
Rval1
Rval2
Rval1
Rval2
Rval3
sw1
sw2
sw3
VSSQ
Switch (sw1, sw2, sw3) is enabled by ODT pin.
Selection among sw1, sw2, and sw3 is determined by “Rtt (nominal)” in EMR (1).
Termination included on all DQs, DM, DQS, DQS , RDQS, and RDQS pins.
Figure 9
– Functional Representation of ODT
7.2.5
ODT related timings
7.2.5.1
MRS command to ODT update delay
During normal operation the value of the effective termination resistance can be changed with an
EMRS command. The update of the Rtt setting is done between tMOD,min and tMOD,max, and CKE
must remain HIGH for the entire duration of tMOD window for proper operation. The timings are shown
in the following timing diagram.
相关PDF资料
PDF描述
W972GG8JB-25I 256M X 8 DDR DRAM, 0.4 ns, PBGA60
W972GG8JB-18 256M X 8 DDR DRAM, 0.35 ns, PBGA60
W9751G6JB-18 32M X 16 DDR DRAM, 0.35 ns, PBGA84
W981204AH-8H 32M X 4 SYNCHRONOUS DRAM, 6 ns, PDSO54
W981216BH75L 8M X 16 SYNCHRONOUS DRAM, 5.4 ns, PDSO54
相关代理商/技术参数
参数描述
W9725G8JB25ITR 制造商:Winbond Electronics Corp 功能描述:256M DDR2-800, X8, IND TEMP
W9725G8JB25TR 制造商:Winbond Electronics Corp 功能描述:256M DDR2-800, X8
W9725G8KB-18 制造商:Winbond Electronics 功能描述:IC MEMORY 制造商:Winbond Electronics Corp 功能描述:IC MEMORY
W9725G8KB-25 制造商:Winbond Electronics 功能描述:IC MEMORY 制造商:Winbond Electronics Corp 功能描述:IC MEMORY
W9725G8KB-25 TR 制造商:Winbond Electronics Corp 功能描述:256M DDR2-800, X8