收藏本站
AT73C224
5.3.2.2
TWI Operation
The TWI interface allows a microcontroller to proceed to read or write accesses to the internal
registers of the AT73C224-x. Unlike the SPI, the TWI operation is based on a standard which
defines a data-link layer and an addressing scheme. The TWI implementation used in the
AT73C224-x conforms to this standard, with the following restrictions:
? slave only
? bit rate: 400 kbps max
? 7-bit fixed address: the default value is 1001001 (D3 is high). But the external D3 bit can
modify it. When D3 is low, the 7-bit fixed address is 1001000 .
? TWCK is an input pin for the clock
? TWD is a bidirectional pin driving (open drain with external resistor connected to V DDIO ) or
receiving the serial data.
The data put on TWD line must be 8 bits long. Data is transferred MSB first. Each byte must be
followed by an acknowledgement. Each transfer begins with a Start condition and terminates
with a STOP condition.
? A high-to-low transition on TWD while TWCK is high defines a START condition.
? A low-to-high transition on TWD while TWCK is high defines a STOP condition.
Figure 5-8.
TWI Start/Stop Condition
TWD
TWCK
START
STOP
Figure 5-9.
TWD
TWCK
TWI Protocol
START
Address
R/W
Ack
Data
Ack
Data
Ack
STOP
After the host initiates a START condition, it sends the 7-bit slave address, as defined above, to
notify the slave device. A Read/Write bit follows (Read = 1, Write = 0). The device acknowledges
each received byte. The first byte sent after device address and R/W bit is the address of the
device register the host wants to read or write. For a write operation, the data follows the internal
address. For a read operation, a repeated START condition needs to be generated followed by
a read on the device.
Write and Read operations are shown in Figure 5-8 and Figure 5-9 .
17
6266A–PMAAC–08-Sep-08
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
AT73C239-EK KIT EVAL FOR AT73C239
AT73C240-EK1 KIT EVALUATION FOR AT73C240
AT73C246-EK1 KIT EVALUATION FOR AT73C246
AT85DVK-07 KIT DEV FOR AT85C51SND3
AT85RFD-07 REFERENCE DESIGN FOR AT85C51SND3
AT88CK101BK8 BOARD KIT CRYPTO W/SOIC SKT
AT88CK101STK8 BOARD KIT CRYPTO W/SOIC&MICRO
AT88CK109BK8 BOARD KIT CRYPTO W/2 SOIC SKTS
相关代理商/技术参数
AT73C224-F 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Power Management and Analog Companions (PMAAC)
AT73C224-G 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Power Management and Analog Companions (PMAAC)
AT73C224-H 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Power Management and Analog Companions (PMAAC)
AT73C225J 功能描述:电池管理 Monolithic numeric RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel
AT73C237 功能描述:其他电源管理 NGD : MONOLITHIC NUMERIC IC RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel
AT73C238 功能描述:电池管理 Monolithic numeric RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel
AT73C239 功能描述:其他电源管理 NGD MONOLITHIC NUMERIC IC RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel
AT73C239_07 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Power Management and Analog Companions (PMAAC)