- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄370207 > FM31256 4Kb FRAM Serial 3V Memory PDF資料下載
參數(shù)資料
| 型號： | FM31256 |
| 元件分類： | F-RAM |
| 英文描述： | 4Kb FRAM Serial 3V Memory |
| 中文描述： | 4Kb的鐵電串行3V的記憶 |
| 文件頁數(shù)： | 15/22頁 |
| 文件大?。?/td> | 170K |
| 代理商： | FM31256 |
should be set to 0 to maintain upward compatibility.
Following the MSB is the LSB (lower byte) which
contains the remaining eight address bits. The
address is latched internally. Each access causes the
latched address to be incremented automatically. The
current address is the value that is held in the latch,
either a newly written value or the address following
the last access. The current address will be held as
long as VDD > VTP or until a new value is written.
Accesses to the clock do not affect the current
memory address. Reads always use the current
address. A random read address can be loaded by
beginning a write operation as explained below.
After transmission of each data byte, just prior to the
Acknowledge, the FM31xxx increments the internal
address. This allows the next sequential byte to be
accessed with no additional addressing externally.
After the last address is reached, the address latch
will roll over to 0000h. There is no limit to the
number of bytes that can be accessed with a single
read or write operation.
FM3104/16/64/256
Rev 0.21
Nov 2003
Page 15 of 22
Addressing Overview – RTC & Companion
The RTC and Processor Companion operate in a
similar manner to the memory, except that it uses
only one byte of address. Addresses 00h to 18h
correspond to special function registers. Attempting
to load addresses above 18h is an illegal condition;
the FM31xxx will return a NACK and abort the 2-
wire transaction.
Data Transfer
After the address information has been transmitted,
data transfer between the bus master and the
FM31xxx begins. For a read, the FM31xxx will
place 8 data bits on the bus then wait for an ACK
from the master. If the ACK occurs, the FM31xxx
will transfer the next byte. If the ACK is not sent, the
FM31xxx will end the read operation. For a write
operation, the FM31xxx will accept 8 data bits from
the master then send an Acknowledge. All data
transfer occurs MSB (most significant bit) first.
Memory Write Operation
All memory writes begin with a Slave Address, then
a memory address. The bus master indicates a write
operation by setting the slave address LSB to a 0.
After addressing, the bus master sends each byte of
data to the memory and the memory generates an
Acknowledge condition. Any number of sequential
bytes may be written. If the end of the address range
is reached internally, the address counter will wrap
to 0000h. Internally, the actual memory write occurs
after the 8
th
data bit is transferred. It will be complete
before the Acknowledge is sent. Therefore, if the
user desires to abort a write without altering the
memory contents, this should be done using a Start
or Stop condition prior to the 8
th
data bit. The figures
below illustrate a single- and multiple-writes to
memory.
S
A
Slave Address
0
Address MSB
A
Data Byte
A
P
By Master
By FM31xxx
Start
Address & Data
Stop
Acknowledge
Address LSB
A
Figure 11. Single Byte Memory Write
S
A
Slave Address
0
Address MSB
A
Data Byte
A
P
By Master
By FM31xxx
Start
Address & Data
Stop
Acknowledge
Address LSB
A
Data Byte
A
Figure 12. Multiple Byte Memory Write
相關PDF資料 |
PDF描述 |
|---|---|
| FM320B | SURFACE MOUNT SCHOTTKY BARRIER RECTIFIER VOLTAGE RANGE 20 to 60 Volts CURRENT 3.0 Amperes |
| FM330B | SURFACE MOUNT SCHOTTKY BARRIER RECTIFIER VOLTAGE RANGE 20 to 60 Volts CURRENT 3.0 Amperes |
| FM340B | SURFACE MOUNT SCHOTTKY BARRIER RECTIFIER VOLTAGE RANGE 20 to 60 Volts CURRENT 3.0 Amperes |
| FM350B | SURFACE MOUNT SCHOTTKY BARRIER RECTIFIER VOLTAGE RANGE 20 to 60 Volts CURRENT 3.0 Amperes |
| FM360B | SURFACE MOUNT SCHOTTKY BARRIER RECTIFIER VOLTAGE RANGE 20 to 60 Volts CURRENT 3.0 Amperes |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| FM31256_11 | 制造商:RAMTRON 制造商全稱:RAMTRON 功能描述:Integrated Processor Companion with Memory |
| FM31256-G | 功能描述:監(jiān)控電路 256K w/RTC Pwr Mon WDT Bat Sw PF RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復位:Resettable 監(jiān)視器:No Watchdog 電池備用開關:No Backup 上電復位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| FM31256-G | 制造商:Ramtron International Corporation 功能描述:Voltage Detector / Microprocessor Superv |
| FM31256-GTR | 功能描述:監(jiān)控電路 256K w/RTC Pwr Mon WDT Bat Sw PF RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復位:Resettable 監(jiān)視器:No Watchdog 電池備用開關:No Backup 上電復位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| FM31256-S | 功能描述:監(jiān)控電路 256K w/RTC Pwr Mon WDT Bat Sw PF RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復位:Resettable 監(jiān)視器:No Watchdog 電池備用開關:No Backup 上電復位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復。