參數(shù)資料
型號: 24LC256-IT/MS
元件分類: PROM
英文描述: 32K X 8 I2C/2-WIRE SERIAL EEPROM, PDSO8
封裝: ROHS COMPLIANT, PLASTIC, MSOP-8
文件頁數(shù): 6/42頁
文件大?。?/td> 797K
代理商: 24LC256-IT/MS
24AAXX/24LCXX/24FCXX
DS21930C-page 14
2007 Microchip Technology Inc.
5.7
Device Addressing For Devices
With Functional Address Pins
A control byte is the first byte received following the
Start condition from the master device (Figure 5-4).
The control byte begins with a 4-bit control code. For
the 24XX, this is set as ‘1010
binary for read and write
operations. The next three bits of the control byte are
the Chip Select bits (A2, A1, A0). The Chip Select bits
allow the use of up to eight 24XX devices on the same
bus and are used to select which device is accessed.
The Chip Select bits in the control byte must corre-
spond to the logic levels on the corresponding A2, A1
and A0 pins for the device to respond. These bits are,
in effect, the three Most Significant bits of the word
address.
For 24XX128 and 24XX256 in the MSOP package, the
A0 and A1 pins are not connected. During device
addressing, the A0 and A1 Chip Select bits (Figure 5-4)
should be set to ‘0’. Only two 24XX128 or 24XX256
MSOP packages can be connected to the same bus.
The last bit of the control byte defines the operation to
be performed. When set to a ‘1’, a read operation is
selected. When set to a ‘0’, a write operation is
selected.
For
higher
density
devices
(24XX32
through
24XX1025), the next two bytes received define the
address of the first data byte. Depending on the prod-
uct density, not all bits in the address high byte are
used. A15, A14, A13 and A12 are “don’t care” for
24XX32. A15, A14 and A13 are “don’t care” for
24XX64. A15 and A14 are “don’t care” for 24XX128.
A15 is “don’t care” for 24XX256. All address bits are
used for the 24XX512 and 24XX1025. The upper
address bits are transferred first, followed by the Less
Significant bits.
Following the Start condition, the 24XX monitors the
SDA bus. Upon receiving a ‘1010
code, appropriate
device select bits and the R/W bit, the slave device out-
puts an Acknowledge signal on the SDA line. The
address byte(s) follow the acknowledge.
The 24XX1025 has an internal address boundary
limitation that is divided into two segments of 512 Kbits.
Block select bit ‘B0’ is used to control access to each
segment. Contiguous writes cannot be performed
across this boundary.
FIGURE 5-4:
CONTROL AND ADDRESS BYTE ASSIGNMENTS FOR
DEVICES WITH ADDRESS PINS
S
10
1
0
A2 A1 A0 R/W ACK
S
10
1
0
A2 A1 A0 R/W ACK
S
10
1
0
A2 A1 A0 R/W ACK
S
10
1
0
A2 A1 A0 R/W ACK
S
10
1
0
A2 A1 A0 R/W ACK
S
10
1
0
B0 A1 A0 R/W ACK
24XX64
24XX128
24XX256
24XX512
x
= “don’t care” bit
Acknowledge
Control Code
Start bit
Control Byte
Chip Select bits*
Address High Byte
24XX32
Read/Write bit
x
xxx
A11 A10 A9 A8
xx
x
A12 A11 A10 A9 A8
xx
A13 A12 A11 A10 A9 A8
x
A14 A13 A12 A11 A10 A9 A8
A15 A14 A13 A12 A11 A10 A9 A8
bit
S
10
1
0
A2
A1
A0
R/W
ACK
S
10
1
0
A2
A1
A0
R/W
ACK
S
10
1
0
A2
A1
A0
R/W
ACK
x
A6
.
A0
A7
.
A0
A7
.
A0
24XX024/025
24C02C
24C01C
Address Byte
A7
.
. A0
A7
.
. A0
A7
.
. A0
A7
.
. A0
A7
.
. A0
A7
.
. A0
Address Low Byte
* Chip Select bits A1 and A0 must be set to ‘0’ for 24XX128/256 devices in the MSOP package.
Control Byte
(Read = 1, Write = 0)
24XX1025
相關(guān)PDF資料
PDF描述
24LC32AIP I2C Serial EEPROM
24LC32AISM I2C Serial EEPROM
24LCS21IP I2C Serial EEPROM
24LCS21ISN High-Speed/Low-Power Microcontrollers
24LCS21P I2C Serial EEPROM
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
24LC256SC/S15K 制造商:Microchip Technology Inc 功能描述:256K I2C SMARTCARD EE DIE IN WAFFLE PK - Gel-pak, waffle pack, wafer, diced wafer on film
24LC256SC/W15K 制造商:Microchip Technology Inc 功能描述:256K I2C SMARTCARD EE WAFER - Gel-pak, waffle pack, wafer, diced wafer on film
24LC256SC/WF15K 制造商:Microchip Technology Inc 功能描述:256K I2C SMARTCARD EE WFR ON FR - Gel-pak, waffle pack, wafer, diced wafer on film
24LC256T-E/MF 功能描述:電可擦除可編程只讀存儲器 256K 32K X 8 2.5V SER EE EXT RoHS:否 制造商:Atmel 存儲容量:2 Kbit 組織:256 B x 8 數(shù)據(jù)保留:100 yr 最大時鐘頻率:1000 KHz 最大工作電流:6 uA 工作電源電壓:1.7 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8
24LC256T-E/MNY 功能描述:電可擦除可編程只讀存儲器 256K, 32Kx8, 2.5V SER EE, ExT RoHS:否 制造商:Atmel 存儲容量:2 Kbit 組織:256 B x 8 數(shù)據(jù)保留:100 yr 最大時鐘頻率:1000 KHz 最大工作電流:6 uA 工作電源電壓:1.7 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8