参数资料
型号: IC41C44002-50JI
英文描述: 4Mx4 bit Dynamic RAM with EDO Page Mode
中文描述: 4Mx4位动态RAM与江户页面模式
文件页数: 15/20页
文件大小: 236K
代理商: IC41C44002-50JI
IC41C4400x and IC41LV4400x Series
4
Integrated Circuit Solution Inc.
DR007-0B 10/17/2002
Functional Description
The IC41C4400x and IC41LV4400x are CMOS DRAMs
optimized for high-speed bandwidth, low power
applications. During READ or WRITE cycles, each bit is
uniquely addressed through the 11 or 12 address bits.
These are entered 11 bits (A0-A10) at a time for the 2K
refresh device or 12 bits (A0-A11) at a time for the 4K
refresh device. The row address is latched by the Row
Address Strobe (
RAS). The column address is latched by
the Column Address Strobe (
CAS). RAS is used to latch
the first nine bits and
CAS is used the latter ten bits.
Memory Cycle
A memory cycle is initiated by bring
RAS LOW and it is
terminated by returning both
RAS and CAS HIGH. To
ensures proper device operation and data integrity any
memory cycle, once initiated, must not be ended or
aborted before the minimum tRAS time has expired. A new
cycle must not be initiated until the minimum precharge
time tRP, tCP has elapsed.
Read Cycle
A read cycle is initiated by the falling edge of
CAS or OE,
whichever occurs last, while holding
WE HIGH. The
column address must be held for a minimum time specified
by tAR. Data Out becomes valid only when tRAC, tAA, tCAC
and tOEA are all satisfied. As a result, the access time is
dependent on the timing relationships between these
parameters.
Write Cycle
A write cycle is initiated by the falling edge of
CAS and WE,
whichever occurs last. The input data must be valid at or
before the falling edge of
CAS or WE, whichever occurs
last.
Refresh Cycle
To retain data, 2,048 refresh cycles are required in each
32 ms period, or 4,096 refresh cycles are required in each
64ms period. There are two ways to refresh the memory:
1. By clocking each of the 2,048 row addresses (A0
through A10) or 4096 row addresses (A0 through A11)
with RAS at least once every 32 ms or 64ms respectively.
Any read, write, read-modify-write or RAS-only cycle
refreshes the addressed row.
2. Using a
CAS-before-RAS refresh cycle. CAS-before-
RAS refresh is activated by the falling edge of RAS,
while holding
CAS LOW. In CAS-before-RAS refresh
cycle, an internal 9-bit counter provides the row ad-
dresses and the external address inputs are ignored.
CAS-before-RAS is a refresh-only mode and no data
access or device selection is allowed. Thus, the output
remains in the High-Z state during the cycle.
Power-On
After application of the VCC supply, an initial pause of
200 s is required followed by a minimum of eight initial-
ization cycles (any combination of cycles containing a
RAS signal).
During power-on, it is recommended that
RAS track with
VCC or be held at a valid VIH to avoid current surges.
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相关代理商/技术参数
参数描述
IC41C44002-50T 制造商:ICSI 制造商全称:Integrated Circuit Solution Inc 功能描述:4Mx4 bit Dynamic RAM with EDO Page Mode
IC41C44002-50TI 制造商:ICSI 制造商全称:Integrated Circuit Solution Inc 功能描述:4Mx4 bit Dynamic RAM with EDO Page Mode
IC41C44002-60J 制造商:ICSI 制造商全称:Integrated Circuit Solution Inc 功能描述:4Mx4 bit Dynamic RAM with EDO Page Mode
IC41C44002-60JI 制造商:ICSI 制造商全称:Integrated Circuit Solution Inc 功能描述:4Mx4 bit Dynamic RAM with EDO Page Mode
IC41C44002-60T 制造商:ICSI 制造商全称:Integrated Circuit Solution Inc 功能描述:4Mx4 bit Dynamic RAM with EDO Page Mode