參數(shù)資料
型號: M41T256YMH
廠商: 意法半導(dǎo)體
英文描述: 256 Kbit 32K x8 SERIAL RTC
中文描述: 256千位32K的x8串行實(shí)時(shí)時(shí)鐘
文件頁數(shù): 9/26頁
文件大小: 363K
代理商: M41T256YMH
9/26
M41T256Y
OPERATING MODES
The M41T256Y clock operates as a slave device
on the serial bus. Access is obtained by imple-
menting a start condition followed by the correct
slave address (D0h). The 256K bytes contained in
the device can then be accessed sequentially in
the following order:
0-7FEF = General Purpose RAM
7FF0-7FF6 = Reserved
7FF7h = Tenths/Hundredths Register
7FF8h = Control Register
7FF9h = Seconds Register
7FFAh = Minutes Register
7FFBh = Hour Register
7FFCh = Tamper/Day Register
7FFDh = Date Register
7FFEh = Month Register
7FFFh = Year Register
The M41T256Y clock continually monitors V
CC
for
an out-of tolerance condition. Should V
CC
fall be-
low V
PFD
, the device terminates an access in
progress and resets the device address counter.
Inputs to the device will not be recognized at this
time to prevent erroneous data from being written
to the device from an out-of-tolerance system.
When V
CC
falls below V
SO
, the device automati-
cally switches over to the battery and powers
down into an ultra low current mode of operation to
conserve battery life. As system power returns and
V
CC
rises above V
SO
, the battery is disconnected,
and the power supply is switched to external V
CC
.
Write protection continues until V
CC
reaches V
PFD
plus t
REC
.
For more information on Battery Storage Life refer
to Application Note AN1012.
2-Wire Bus Characteristics
The bus is intended for communication between
different ICs. It consists of two lines: a bi-direction-
al data signal (SDA) and a clock signal (SCL).
Both the SDA and SCL lines must be connected to
a positive supply voltage via a pull-up resistor.
The following protocol has been defined:
– Data transfer may be initiated only when the bus
is not busy.
– During data transfer, the data line must remain
stable whenever the clock line is High.
– Changes in the data line, while the clock line is
High, will be interpreted as control signals.
Accordingly, the following bus conditions have
been defined:
Bus not busy.
Both data and clock lines remain
High.
Start data transfer.
A change in the state of the
data line, from High to Low, while the clock is High,
defines the START condition.
Stop data transfer.
A change in the state of the
data line, from Low to High, while the clock is High,
defines the STOP condition.
Data Valid.
The state of the data line represents
valid data when after a start condition, the data line
is stable for the duration of the high period of the
clock signal. The data on the line may be changed
during the Low period of the clock signal. There is
one clock pulse per bit of data.
Each data transfer is initiated with a start condition
and terminated with a stop condition. The number
of data bytes transferred between the start and
stop conditions is not limited. The information is
transmitted byte-wide and each receiver acknowl-
edges with a ninth bit.
By definition a device that gives out a message is
called “transmitter,” the receiving device that gets
the message is called “receiver.” The device that
controls the message is called “master.” The de-
vices that are controlled by the master are called
“slaves.”
Acknowledge.
Each byte of eight bits is followed
by one acknowledge clock pulse. This acknowl-
edge clock pulse is a low level put on the bus by
the receiver whereas the master generates an ex-
tra acknowledge related clock pulse. A slave re-
ceiver which is addressed is obliged to generate
an acknowledge after the reception of each byte
that has been clocked out of the slave transmitter.
The device that acknowledges has to pull down
the SDA line during the acknowledge clock pulse
in such a way that the SDA line is a stable Low dur-
ing the High period of the acknowledge related
clock pulse. Of course, setup and hold times must
be taken into account. A master receiver must sig-
nal an end of data to the slave transmitter by not
generating an acknowledge on the last byte that
has been clocked out of the slave. In this case the
transmitter must leave the data line High to enable
the master to generate the STOP condition.
相關(guān)PDF資料
PDF描述
M41T256YMT 256 Kbit 32K x8 SERIAL RTC
M41T256YMT7TR RCA-F TO RCA-F COUPLER
M41T256YMT7 RCA F TO BNC-M ADAPTER
M41T315W-65MH6E Serial Access Phantom RTC Supervisor
M41T315W-65MH6F Serial Access Phantom RTC Supervisor
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
M41T256YMH7 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:256 Kbit 32K x8 SERIAL RTC
M41T256YMH7E 功能描述:實(shí)時(shí)時(shí)鐘 Serial 256K (32Kx8) RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時(shí)間格式:HH:MM:SS RTC 存儲(chǔ)容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
M41T256YMH7F 功能描述:實(shí)時(shí)時(shí)鐘 Serial 256K (32Kx8) RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時(shí)間格式:HH:MM:SS RTC 存儲(chǔ)容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
M41T256YMH7TR 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:256 Kbit 32K x8 SERIAL RTC
M41T256YMT 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:256 Kbit 32K x8 SERIAL RTC