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CMS4A16LAF 参数 Datasheet PDF下载

CMS4A16LAF图片预览
型号: CMS4A16LAF
PDF下载: 下载PDF文件 查看货源
内容描述: 128M ( 8Mx16 )低功耗SDRAM [128M(8Mx16) Low Power SDRAM]
分类和应用: 动态存储器
文件页数/大小: 46 页 / 616 K
品牌: FIDELIX [ FIDELIX ]
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CMS4A16LAx–75Ex  
Table 3. CAS Latency.  
Speed  
Allowable Operating Frequency (MHz)  
CAS Latency = 1  
CAS Latency = 2  
CAS Latency = 3  
133  
133MHz  
100MHz  
50  
40  
100  
83  
100  
EXTENDED MODE REGISTER  
PARTIAL ARRAY SELF REFRESH  
The Extended Mode Register controls additional functions such  
as Partial Array Self Refresh (PASR) and Driver Strength (DS).  
The Extended Mode Register is programmed via the Mode  
Register Set command (BA1=1, BA0=0) and retains the stored  
information until it is programmed again or the device loses  
power. The Extended Mode Register must be programmed with  
M8 through M11 set to “0”. The Extended Mode Register must  
be loaded when all banks are idle and no bursts are in progress,  
and the controller must wait the specified time initiating any  
subsequent operation. Violating either of these requirements  
results in unspecified operation.  
The Partial Array Self Refresh (PASR) feature allows the con-  
troller to select the amount of memory that will be refreshed  
during SELF REFRESH. The refresh options are all banks  
(banks 0, 1, 2, and 3); two banks(banks 0 and 1 or 2 and 3 by  
M7); and one bank (bank 0 or 2 by M7). WRITE and READ  
commands occur to any bank selected during standard  
operation, but only the selected banks in PASR will be  
refreshed during SELF REFRESH. The data in the deselected  
bank will be lost.  
Driver Strength Control  
AUTO TEMPERATURE COMPENSATED SELF REFRESH  
The driver strength feature allows one to reduce the  
drive strength of the I/O’s on the device during low frequency  
operation. This allows systems to reduce the noise associated  
with the I/O’s switching.  
Every cell in the DRAM requires refreshing due to the capacitor  
losing its charge over time. The refresh rate is dependent on  
temperature. At higher temperatures a capacitor loses charge  
quicker than at lower temperatures, requiring the cells to be  
refreshed more often. In order to save power consumption,  
according to the temperature, Mobile-SDRAM includes the  
internal temperature sensor and control units to control the self  
refresh cycle automatically.  
EM13- EM12- EM11- EM10-  
EM9-  
A9  
EM8-  
A8  
EM7-  
A7  
EM6-  
A6  
EM5-  
A5  
EM4-  
A4  
EM3-  
A3  
EM2-  
A2  
EM1-  
A1  
EM0-  
A0  
BA1  
BA0  
A11  
A10  
Bank  
1
0
All must be set to ‘0’  
Driver Strength  
0
0
PASR  
Up/Down  
11  
Rev. 0.5, May. ‘07