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| 型号： | W9725G6JB25I |
| 厂商： | Winbond Electronics |
| 文件页数： | 23/87页 |
| 文件大小： | 0K |
| 描述： | IC DDR2 SDRAM 256MBIT 84WBGA |
| 标准包装： | 200 |
| 格式 - 存储器： | RAM |
| 存储器类型： | DDR2 SDRAM |
| 存储容量： | 256M（16Mx16） |
| 速度： | 2.5ns |
| 接口： | 并联 |
| 电源电压： | 1.7 V ~ 1.9 V |
| 工作温度： | -40°C ~ 95°C |
| 封装/外壳： | 84-TFBGA |
| 供应商设备封装： | 84-WBGA（8x12.5） |
| 包装： | 托盘 |
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W9725G6JB
7.3.10 No-Operation Command
( CS = "L", RAS = "H", CAS = "H", WE = "H", CKE, BA0, BA1, A0 to A12 = Don?t Care )
The No-Operation command simply performs no operation (same command as Device Deselect).
7.3.11 Device Deselect Command
( CS = "H", RAS , CAS , WE , CKE, BA0, BA1, A0 to A12 = Don?t Care )
The Device Deselect command disables the command decoder so that the RAS , CAS , WE and
Address inputs are ignored. This command is similar to the No-Operation command.
7.4
Read and Write access modes
The 4 Mbit x 16 I/O x 4 Bank chip has a page length of 512 bits (defined by CA0 to CA8) . The page
The DDR2 SDRAM provides a fast column access operation. A single Read or Write Command will
initiate a serial read or write operation on successive clock cycles. The boundary of the burst cycle is
strictly restricted to specific segments of the page length.
*
length of 512 is divided into 128 or 64 uniquely addressable boundary segments depending on burst
length, 128 for 4 bit burst, 64 for 8 bit burst respectively. A 4-bit or 8-bit burst operation will occur
entirely within one of the 128 or 64 groups beginning with the column address supplied to the device
during the Read or Write Command (CA0 to CA8). The second, third and fourth access will also occur
within this group segment. However, the burst order is a function of the starting address, and the burst
sequence.
A new burst access must not interrupt the previous 4 bit burst operation in case of BL = 4 setting.
However, in case of BL = 8 setting, two cases of interrupt by a new burst access are allowed, one
reads interrupted by a read, the other writes interrupted by a write with 4 bit burst boundary
respectively. The minimum CAS to CAS delay is defined by t CCD , and is a minimum of 2 clocks for
read or write cycles.
Note: Page length is a function of I/O organization and column addressing
4M bits × 16 organization (CA0 to CA8); Page Length = 512 bits
7.4.1
Posted CAS
Posted CAS operation is supported to make command and data bus efficient for sustainable
bandwidths in DDR2 SDRAM. In this operation, the DDR2 SDRAM allows a CAS read or write
command to be issued immediately after the RAS bank activate command (or any time during the
RAS - CAS -delay time, t RCD , period). The command is held for the time of the Additive Latency (AL)
before it is issued inside the device. The Read Latency (RL) is controlled by the sum of AL and the
CAS Latency (CL). Therefore if a user chooses to issue a Read/Write command before the t RCDmin ,
then AL (greater than 0) must be written into the EMR (1). The Write Latency (WL) is always defined
as RL -1 (Read Latency -1) where Read Latency is defined as the sum of Additive Latency plus CAS
Latency (RL = AL + CL). Read or Write operations using AL allow seamless bursts. (Example timing
waveforms refer to 10.10 and 10.11 seamless burst read/write operation diagram in Chapter 10)
7.4.1.1
Examples of posted CAS operation
Examples of a read followed by a write to the same bank where AL = 2 and where AL = 0 are shown
in Figures 14 and 15, respectively.
Publication Release Date: Nov. 29, 2011
- 23 -
Revision A02
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| W9725G6KB-25I | IC DDR2 SDRAM 256MBIT 84WBGA |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| W9725G6KB-18 | 制造商:Winbond Electronics 功能描述:IC MEMORY 制造商:Winbond Electronics Corp 功能描述:IC MEMORY |
| W9725G6KB-25 | 功能描述:IC DDR2 SDRAM 256MBIT 84WBGA RoHS:是 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:1 系列:- 格式 - 存储器:闪存 存储器类型:闪存 - NAND 存储容量:4G（256M x 16） 速度:- 接口:并联 电源电压:2.7 V ~ 3.6 V 工作温度:0°C ~ 70°C 封装/外壳:48-TFSOP（0.724"，18.40mm 宽） 供应商设备封装:48-TSOP I 包装:Digi-Reel® 其它名称:557-1461-6 |
| W9725G6KB-25 TR | 制造商:Winbond Electronics Corp 功能描述:256M DDR2-800, X16 |
| W9725G6KB25A | 制造商:WINBOND 制造商全称:Winbond 功能描述:DLL aligns DQ and DQS transitions with clock, Data masks (DM) for write data, Write Data Mask |
| W9725G6KB25I | 制造商:Winbond Electronics Corp 功能描述:DRAM Chip DDR2 SDRAM 256M-Bit 16Mx16 1.8V 84-Pin WBGA 制造商:Winbond Electronics 功能描述:IC DDR2 SDRAM 256M 2.5NS 84WBGA 制造商:Winbond Electronics Corp 功能描述:IC DDR2 SDRAM 256M 2.5NS 84WBGA 制造商:Winbond 功能描述:DRAM Chip DDR2 SDRAM 256M-Bit 16Mx16 1.8V 84-Pin WBGA |
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