參數資料
型號: AS4SD4M16A2-10
英文描述: x16 SDRAM
中文描述: x16內存
文件頁數: 17/51頁
文件大?。?/td> 1071K
代理商: AS4SD4M16A2-10
S DR A M
AS4SD16M16
Austin Semiconductor, Inc.
AS4SD16M16
Rev. 1.5 6/03
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
17
Data for any WRITE burst may be truncated with a
subsequent READ command, and data for a fixed-length WRITE
burst may be immediately followed by a READ command. Once
the READ command is registered, the data inputs will be
ignored, and WRITEs will not be executed. An example is shown
in Figure 17. Data
n
+1 is either the last of a burst of two or the
last desired of a longer burst.
Data for a fixed-length WRITE burst may be followed by,
or truncated with, a PRECHARGE command to the same bank
(provided that auto precharge was not activated), and a full-
page WRITE burst may be truncated with a PRECHARGE com-
mand to the same bank. The PRECHARGE command should be
issued t
WR
after the clock edge at which the last desired input
data element is registered. The auto precharge mode requires a
t
WR
of at least one clock plus time, regardless of frequency. In
addition, when truncating a WRITE burst, the DQM signal must
be used to mask input data for the clock edge prior to, and the
clock edge coincident with, the PRECHARGE command. An
example is shown in Figure 18. Data n+1 is either the last of a
burst of two or the last desired of a longer burst. Following the
PRECHARGE command, a subsequent command to the same
bank cannot be issued until tRP is met. The precharge can be
issued coincident with the first coincident clock edge (T2 in
Figure 18) on an A1 Version and with the second clock on an
A2 Version (Figure 18).
In the case of a fixed-length burst being executed to
completion, a PRECHARGE command issued at the optimum
time (as described above) provides the same operation that
would result from the same fixed-length burst with auto
precharge. The disadvantage of the PRECHARGE command is
that is requires that the command and address buses be
available at the appropriate time to issue the command; the
advantage of the PRECHARGE command is that it can be used
to truncate fixed-length or full-page bursts.
FIGURE 16: Random WRITE Cycles
FIGURE 17: WRITE to READ
FIGURE 18: WRITE to PRECHARGE
相關PDF資料
PDF描述
AS4SD4M16A2-8 x16 SDRAM
AS5010 Voltage Reference
AS5010GN Voltage Reference
AS5010HN Voltage Reference
AS5010JT Voltage Reference
相關代理商/技術參數
參數描述
AS4SD4M16A2-8 制造商:未知廠家 制造商全稱:未知廠家 功能描述:x16 SDRAM
AS4SD4M16DG-10/IT 制造商:未知廠家 制造商全稱:未知廠家 功能描述:4 Meg x 16 SDRAM Synchronous DRAM Memory
AS4SD4M16DG-10/XT 制造商:Micross Components 功能描述:SDRAM-SDR,64MB - Trays
AS4SD4M16DG-8/ET 制造商:Micross Components 功能描述:SDRAM-SDR,64MB - Trays
AS4SD4M16DG-8/IT 制造商:Micross Components 功能描述:SDRAM-SDR,64MB - Trays