欢迎访问ic37.com |
会员登录 免费注册
发布采购

EM68932DVKB-6H 参数 Datasheet PDF下载

EM68932DVKB-6H图片预览
型号: EM68932DVKB-6H
PDF下载: 下载PDF文件 查看货源
内容描述: 4M ×32的移动DDR同步DRAM (SDRAM)的 [4M x 32 Mobile DDR Synchronous DRAM (SDRAM)]
分类和应用: 动态存储器双倍数据速率
文件页数/大小: 40 页 / 342 K
品牌: ETRON [ ETRON TECHNOLOGY, INC. ]
 浏览型号EM68932DVKB-6H的Datasheet PDF文件第7页浏览型号EM68932DVKB-6H的Datasheet PDF文件第8页浏览型号EM68932DVKB-6H的Datasheet PDF文件第9页浏览型号EM68932DVKB-6H的Datasheet PDF文件第10页浏览型号EM68932DVKB-6H的Datasheet PDF文件第12页浏览型号EM68932DVKB-6H的Datasheet PDF文件第13页浏览型号EM68932DVKB-6H的Datasheet PDF文件第14页浏览型号EM68932DVKB-6H的Datasheet PDF文件第15页  
EM68932DVKB  
EtronTech  
z Burst Interruption  
Read Interrupted by Read  
Burst Read can be interrupted before completion of the burst by a new Read command to any bank. When  
the previous burst is interrupted, data bits from the remaining addresses are overridden by data from the  
new addresses with the full burst length. The data from the previous Read command continues to appear  
on the outputs until the CAS latency from the interrupting Read command is satisfied. At this point the data  
from the interrupting Read command appears. The Read to Read interval is a minimum of 1 clock.  
Read Interrupted by Burst Stop & Write  
To interrupt Burst Read with a write command, the Burst Stop command must be asserted to avoid data  
contention on the I/O bus by placing the DQ (output drivers) in a high impedance state. To ensure the DQ  
are tri-stated one cycle before the beginning of the write operation, the Burst Stop command must be  
applied at least 2 clock cycles for CL = 2 and at least 3 clock cycles for CL = 3 before the Write command.  
Read Interrupted by Precharge  
Burst Read can be interrupted by a Precharge of the same bank. A minimum of 1 clock cycle is required for  
the read precharge interval. A Precharge command to output disable latency is equivalent to the  
latency.  
CAS  
Write Interrupted by Write  
A Burst Write can be interrupted by the new Write command before completion of the previous Burst Write,  
with the only restriction being that the interval that separates the commands must be at least one clock  
cycle. When the previous burst is interrupted, the remaining addresses are overridden by the new  
addresses and the new data will be written into the device until the programmed Burst Length is satisfied.  
Write Interrupted by Read & DM  
A Burst Write can be interrupted by a Read command to any bank. The DQ must be in the high impedance  
state at least one clock cycle before the interrupting read data appears on the outputs to avoid data  
contention. When the Read command is to be asserted, any residual data from the Burst Write sequence  
must be masked by DM. The delay from the last data to the Read command (tWTR) is required to avoid data  
contention inside the DRAM. Data presented on the DQ pins before the Read command is initiated will  
actually be written to the memory. A Read command interrupting a write sequence can not be issued at the  
next clock edge following the Write command.  
Write Interrupted by Precharge & DM  
A Burst Write can be interrupted by a Precharge of the same bank before completion of the previous burst.  
A write recovery time (tWR) is required from the last data to the Precharge command. When the Precharge  
command is asserted, any residual data from the Burst Write cycle must be masked by DM.  
z Burst Stop Command  
The Burst Stop command is initiated by having  
and  
High with  
and  
Low at the rising  
WE  
RAS  
CAS  
CS  
edge of the clock only. The Burst Stop command has the fewest restrictions, making it the easiest method  
to use when terminating a burst operation before it has been completed. When the Burst Stop command is  
issued during a Burst Read cycle, both the data and DQS (Data Strobe) go to a high impedance state after  
a delay which is equal to the  
latency set in the Mode Register. The Burst Stop command, however, is  
CAS  
not supported during a Burst Write operation.  
Etron Confidential  
11  
Rev. 1.0  
Aug. 2009