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參數(shù)資料
| 型號(hào)： | STK1744-D45I |
| 廠商： | Electronic Theatre Controls, Inc. |
| 英文描述： | 32K x 8 AutoStore nvSRAM with Real-Time Clock |
| 中文描述： | 32K的× 8自動(dòng)存儲(chǔ)非易失實(shí)時(shí)時(shí)鐘 |
| 文件頁(yè)數(shù)： | 9/12頁(yè) |
| 文件大?。?/td> | 315K |
| 代理商： | STK1744-D45I |
STK1744
January 2003
9
Document Control # ML0020 rev 0.0
accessed during this period. It is important that
READ
cycles and not
WRITE
cycles be used in the
sequence, although it is not necessary that G be
low for the sequence to be valid. After the t
STORE
cycle time has been fulfilled, the
SRAM
will again be
activated for
READ
and
WRITE
operation.
SOFTWARE NONVOLATILE
RECALL
A software
RECALL
cycle is initiated with a
sequence of
READ
operations in a manner similar
to the software
STORE
initiation. To initiate the
RECALL
cycle, the following sequence of
READ
operations must be performed:
1.
2.
3.
4.
5.
6.
Read address
Read address
Read address
Read address
Read address
Read address
0E38 (hex)
31C7 (hex)
03E0 (hex)
3C1F (hex)
303F (hex)
0C63 (hex)
Valid READ
Valid READ
Valid READ
Valid READ
Valid READ
Initiate
RECALL
cycle
Internally,
RECALL
is a two-step procedure. First,
the
SRAM
data is cleared, and second, the nonvola-
tile information is transferred into the
SRAM
cells.
After the t
RECALL
cycle time the
SRAM
will once again
be ready for
READ
and
WRITE
operations. The
RECALL
operation in no way alters the data in the
Nonvolatile Elements. The nonvolatile data can be
recalled an unlimited number of times. Note that
the
RTC
registers are not affected by nonvolatile
operations.
AutoStore
TM
OPERATION
The STK1744 uses capacitance built into the mod-
ule to perform an automatic
STORE
on power down.
In order to prevent unnecessary
STORE
operations,
automatic
STORE
s will be ignored unless at least
one
WRITE
operation has taken place since the
most recent
STORE
or
RECALL
cycle. Software-
initiated
STORE
cycles are performed regardless of
whether a
WRITE
operation has taken place.
POWER-UP
RECALL
During power up, or after any low-power condition
(V
CC
< V
RESET
), an internal
RECALL
request will be
latched. When V
CC
once again exceeds V
SWITCH
, a
RECALL
cycle will automatically be initiated and will
take t
RESTORE
to complete.
If the STK1744 is in a
WRITE
state at the end of
power-up
RECALL
, the
SRAM
data will be corrupted.
To help avoid this situation, a 10K Ohm resistor
should be connected either between W and system
V
CC
or between E and system V
CC
.
HARDWARE PROTECT
The STK1744 offers hardware protection against
inadvertent
STORE
and
SRAM WRITE
operation dur-
ing low-voltage conditions. When V
CC
< V
SWITCH
, all
software
STORE
operations and
SRAM
WRITE
s are
inhibited.
LOW AVERAGE ACTIVE POWER
The STK1744 draws significantly less current when
it is cycled at times longer than 50ns. Figure 2
shows the relationship between I
CC
and
READ
cycle
time. Worst-case current consumption is shown for
both
CMOS
and
TTL
input levels (commercial tem-
perature range, V
CC
= 5.5V, 100% duty cycle on chip
enable). Figure 3 shows the same relationship for
WRITE
cycles. If the chip enable duty cycle is less
than 100%, only standby current is drawn when the
chip is disabled. The overall average current drawn
by the STK1744 depends on the following items:
1)
CMOS
vs.
TTL
input levels; 2) the duty cycle of
chip enable; 3) the overall cycle rate for accesses;
4) the ratio of
READ
s to
WRITE
s; 5) the operating
temperature; 6) the V
CC
level; and 7) I/O loading.
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| STK17T88-RF25I | 功能描述:NVRAM 32Kbx8+RTC 2.7-3.6V RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲(chǔ)容量:1024 Kbit 組織:128 K x 8 接口類(lèi)型:Parallel 訪問(wèn)時(shí)間:70 ns 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 工作電流:85 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 封裝 / 箱體:EDIP 封裝:Tube |
| STK17T88-RF25ITR | 功能描述:NVRAM 32Kbx8+RTC 2.7-3.6V RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲(chǔ)容量:1024 Kbit 組織:128 K x 8 接口類(lèi)型:Parallel 訪問(wèn)時(shí)間:70 ns 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 工作電流:85 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 封裝 / 箱體:EDIP 封裝:Tube |
| STK17T88-RF25TR | 功能描述:NVRAM 32Kbx8+RTC 2.7-3.6V RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲(chǔ)容量:1024 Kbit 組織:128 K x 8 接口類(lèi)型:Parallel 訪問(wèn)時(shí)間:70 ns 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 工作電流:85 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 封裝 / 箱體:EDIP 封裝:Tube |
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