参数资料
型号: 24LCS21P
英文描述: I2C Serial EEPROM
中文描述: I2C串行EEPROM的
文件页数: 11/12页
文件大小: 159K
代理商: 24LCS21P
24LCS21
DS21127D-page 8
1999 Microchip Technology Inc.
4.2
Page Write
The write control byte, word address and the rst data
byte are transmitted to the 24LCS21 in the same way
as in a byte write. But instead of generating a stop
condition the master transmits up to eight data bytes to
the 24LCS21 which are temporarily stored in the
on-chip page buffer and will be written into the memory
after the master has transmitted a stop condition. After
the receipt of each word, the three lower order address
pointer bits are internally incremented by one. The
higher order ve bits of the word address remains
constant. If the master should transmit more than eight
words prior to generating the stop condition, the
address counter will roll over and the previously
received data will be overwritten. As with the byte write
operation, once the stop condition is received an
internal write cycle will begin (Figure 5-2).
It is required that VCLK be held at a logic high level
during command and data transfer in order to program
the device. This applies to both byte write and page
write operation. Note, however, that the VCLK is
ignored during the self-timed program operation.
Changing VCLK from high to low during the self-timed
program operation will not halt programming of the
device.
5.0
ACKNOWLEDGE POLLING
Since the device will not acknowledge during a write
cycle, this can be used to determine when the cycle is
complete (this feature can be used to maximize bus
throughput). Once the stop condition for a write
command has been issued from the master, the device
initiates the internally timed write cycle. ACK polling
can be initiated immediately. This involves the master
sending a start condition followed by the control byte for
a write command (R/W = 0). If the device is still busy
with the write cycle, then no ACK will be returned. If the
cycle is complete, then the device will return the ACK
and the master can then proceed with the next read or
write command. See Figure 5-1 for the ow diagram.
FIGURE 5-1: ACKNOWLEDGE POLLING FLOW
Note:
Page write operations are limited to writing
bytes within a single physical page, regard-
less of the number of bytes actually being
written. Physical page boundaries start at
addresses that are integer multiples of the
page buffer size (or page size) and end at
addresses that are integer multiples of
[page size - 1]. If a page write command
attempts to write across a physical page
boundary, the result is that the data wraps
around to the beginning of the current page
(overwriting data previously stored there),
instead of being written to the next page as
might be expected. It is therefore neces-
sary for the application software to prevent
page write operations that would attempt to
cross a page boundary.
Did Device
Acknowledge
(ACK = 0)?
Send
Write Command
Send Stop
Condition to
Initiate Write Cycle
Send Start
Send Control Byte
with R/W = 0
Next
Operation
No
Yes
FIGURE 5-2: PAGE WRITE
BUS
MASTER
SDA LINE
BUS
CONTROL
BYTE
WORD
ADDRESS
S
T
O
P
S
T
A
R
T
A
C
K
A
C
K
A
C
K
ACTIVITY:
A
C
K
A
C
K
DATA n + 1
DATA n + 7
DATA (n)
P
S
VCLK
This Material Copyrighted by Its Respective Manufacturer
相关PDF资料
PDF描述
24LCS21SN I2C Serial EEPROM
24LCS21TISN I2C Serial EEPROM
24LCS21TSN I2C Serial EEPROM
24LCS22A 24LCS22A Datasheet
24PCAFA1D Industrial Control IC
相关代理商/技术参数
参数描述
24LCS22A-I/P 功能描述:电可擦除可编程只读存储器 VESA E-EDID RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
24LCS22A-I/PG 功能描述:电可擦除可编程只读存储器 VESA E-EDID Lead Free Package RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
24LCS22A-I/SN 功能描述:电可擦除可编程只读存储器 VESA E-EDID RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
24LCS22A-I/SNG 功能描述:电可擦除可编程只读存储器 VESA E-EDID Lead Free Package RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
24LCS22AT-I/SN 功能描述:电可擦除可编程只读存储器 VESA E-EDID RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8