參數(shù)資料
型號(hào): X24C44DI
英文描述: Serial Nonvolatile Static RAM
中文描述: 串行非易失性靜態(tài)RAM
文件頁(yè)數(shù): 3/15頁(yè)
文件大?。?/td> 60K
代理商: X24C44DI
X24C44
3
DEVICE OPERATION
The X24C44 contains an 8-bit instruction register. It is
accessed via the DI input, with data being clocked in on
the rising edge of SK. CE must be HIGH during the entire
data transfer operation.
Table 1. contains a list of the instructions and their
operation codes. The most significant bit (MSB) of all
instructions is a logic one (HIGH), bits 6 through 3 are
either RAM address bits (A) or don’t cares (X) and bits
2 through 0 are the operation codes. The X24C44
requires the instruction to be shifted in with the MSB first.
After CE is HIGH, the X24C44 will not begin to interpret
the data stream until a logic “1” has been shifted in on DI.
Therefore, CE may be brought HIGH with SK running
and DI LOW. DI must then go HIGH to indicate the start
condition of an instruction before the X24C44 will begin
any action.
In addition, the SK clock is totally static. The user can
completely stop the clock and data shifting will be stopped.
Restarting the clock will resume shifting of data.
RCL and
RECALL
Either a software RCL instruction or a LOW on the
RECALL
input will initiate a transfer of E
2
PROM data
into RAM. This software or hardware recall operation
sets an internal “previous recall” latch. This latch is reset
upon power-up and must be intentionally set by the user
to enable any write or store operations. Although a recall
operation is performed upon power-up, the previous
recall latch is not set by this operation.
WRDS and WREN
Internally the X24C44 contains a “write enable” latch. This
latch must be set for either writes to the RAM or store
operations to the E
2
PROM. The WREN instruction sets
the latch and the WRDS instruction resets the latch,
disabling both RAM writes and E
2
PROM stores, effec-
tively protecting the nonvolatile data from corruption. The
write enable latch is automatically reset on power-up.
STO and
STORE
Either the software STO instruction or a LOW on the
STORE
input will initiate a transfer of data from RAM to
E
2
PROM. In order to safeguard against unwanted store
operations, the following conditions must be true:
STO instruction issued or
STORE
input is LOW.
The internal “write enable” latch must be set
(WREN instruction issued).
The “previous recall” latch must be set (either a
software or hardware recall operation).
Once the store cycle is initiated, all other device func-
tions are inhibited. Upon completion of the store cycle,
the write enable latch is reset. Refer to Figure 4 for a
state diagram description of enabling/disabling condi-
tions for store operations.
WRITE
The WRITE instruction contains the 4-bit address of the
word to be written. The write instruction is immediately
followed by the 16-bit word to be written. CE must remain
HIGH during the entire operation. CE must go LOW
before the next rising edge of SK. If CE is brought LOW
prematurely (after the instruction but before 16 bits of data
are transferred), the instruction register will be reset and
the data that was shifted-in will be written to RAM.
If CE is kept HIGH for more than 24 SK clock cycles (8-bit
instruction plus 16-bit data), the data already shifted-in will
be overwritten.
Table 1. Instruction Set
Instruction
Format, I
2
I
1
I
0
1XXXX000
1XXXX001
1XXXX010
1AAAA011
1XXXX100
1XXXX101
1AAAA11X
Operation
WRDS (Figure 3)
STO (Figure 3)
Reserved
WRITE (Figure 2)
WREN (Figure 3)
RCL (Figure 3)
READ (Figure 1)
Reset Write Enable Latch (Disables Writes and Stores)
Store RAM Data in E
2
PROM
N/A
Write Data into RAM Address AAAA
Set Write Enable Latch (Enables Writes and Stores)
Recall E
2
PROM Data into RAM
Read Data from RAM Address AAAA
3832 PGM T13
X = Don't Care
A = Address
相關(guān)PDF資料
PDF描述
X24C44DM Serial Nonvolatile Static RAM
X24C44PI Serial Nonvolatile Static RAM
X24C44PM Serial Nonvolatile Static RAM
X24C44SI Serial Nonvolatile Static RAM
X24C44SM Serial Nonvolatile Static RAM
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
X24C44DM 制造商:XICOR 制造商全稱:Xicor Inc. 功能描述:Serial Nonvolatile Static RAM
X24C44P 功能描述:IC NVSRAM 256BIT 1MHZ 8DIP RoHS:否 類別:集成電路 (IC) >> 存儲(chǔ)器 系列:- 標(biāo)準(zhǔn)包裝:150 系列:- 格式 - 存儲(chǔ)器:EEPROMs - 串行 存儲(chǔ)器類型:EEPROM 存儲(chǔ)容量:4K (2 x 256 x 8) 速度:400kHz 接口:I²C,2 線串口 電源電壓:2.5 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 封裝/外殼:8-VFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:8-DFN(2x3) 包裝:管件 產(chǎn)品目錄頁(yè)面:1445 (CN2011-ZH PDF)
X24C44PI 制造商:XICOR 制造商全稱:Xicor Inc. 功能描述:Serial Nonvolatile Static RAM
X24C44PM 制造商:XICOR 制造商全稱:Xicor Inc. 功能描述:Serial Nonvolatile Static RAM
X24C44S 功能描述:IC NVSRAM 256BIT 1MHZ 8SOIC RoHS:否 類別:集成電路 (IC) >> 存儲(chǔ)器 系列:- 標(biāo)準(zhǔn)包裝:150 系列:- 格式 - 存儲(chǔ)器:EEPROMs - 串行 存儲(chǔ)器類型:EEPROM 存儲(chǔ)容量:4K (2 x 256 x 8) 速度:400kHz 接口:I²C,2 線串口 電源電壓:2.5 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 封裝/外殼:8-VFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:8-DFN(2x3) 包裝:管件 產(chǎn)品目錄頁(yè)面:1445 (CN2011-ZH PDF)