- 您现在的位置：买卖IC网 > Sheet目录395 > ATMEGA128RFA1-ZUR (Atmel)IC AVR MCU 2.4GHZ XCEIVER 64QFN
ATmega128
Multi-master
Systems and
Arbitration
If multiple masters are connected to the same bus, transmissions may be initiated simultane-
ously by one or more of them. The T W I standard ensures that such situations are handled in
such a way that one of the masters will be allowed to proceed with the transfer, and that no data
will be lost in the process. An example of an arbitration situation is depicted below, where two
masters are trying to transmit data to a slave receiver.
Figure 105. An Arbitration Example
V CC
Device 1
MASTER
Device 2
MASTER
Device 3
SLAVE
........
Device n
R1
R2
TRANSMITTER
TRANSMITTER
RECEIVER
SDA
SCL
Several different scenarios may arise during arbitration, as described below:
?
?
?
Two or more masters are performing identical communication with the same slave. In this
case, neither the slave nor any of the masters will know about the bus contention.
Two or more masters are accessing the same slave with different data or direction bit. In this
case, arbitration will occur, either in the READ/ W RITE bit or in the data bits. The masters
trying to output a one on SDA while another master outputs a zero will lose the arbitration.
Losing masters will switch to not addressed slave mode or wait until the bus is free and
transmit a new START condition, depending on application software action.
Two or more masters are accessing different slaves. In this case, arbitration will occur in the
SLA bits. Masters trying to output a one on SDA while another master outputs a zero will
lose the arbitration. Masters losing arbitration in SLA will switch to slave mode to check if
they are being addressed by the winning master. If addressed, they will switch to SR or ST
mode, depending on the value of the READ/ W RITE bit. If they are not being addressed, they
will switch to not addressed slave mode or wait until the bus is free and transmit a new
START condition, depending on application software action.
This is summarized in Figure 106 . Possible status values are given in circles.
225
2467X–AVR–06/11
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
ATMEGA64RZAPV-10AU
BUNDLE ATMEGA644P/AT86RF230 TQFP
ATP101-TL-H
MOSFET P-CH 30V 25A ATPAK
ATP102-TL-H
MOSFET P-CH 30V 40A ATPAK
ATP103-TL-H
MOSFET P-CH 30V 55A ATPAK
ATP104-TL-H
MOSFET P-CH 30V 75A ATPAK
ATP106-TL-H
MOSFET P-CH 40V 30A ATPAK
ATP107-TL-H
MOSFET P-CH 40V 50A ATPAK
ATP108-TL-H
MOSFET P-CH 40V 70A ATPAK
相关代理商/技术参数
ATMEGA128RFA1-ZUR SL514
制造商:Atmel Corporation 功能描述:
ATMEGA128RFA1-ZUR00
制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC REVF 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC REVF T&R - Bulk 制造商:Atmel from Components Direct 功能描述:ATMEL ATMEGA128RFA1-ZUR00 MICROCONTROLLERS (MCU) 制造商:Atmel 功能描述:Atmel ATMEGA128RFA1-ZUR00 Microcontrollers (MCU) 制造商:Atmel Corporation 功能描述:MCU AVR 2.4GHZ 128K FLASH 64VQFN 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC Revision F 制造商:Atmel 功能描述:2.4GHZ 802.15.4 128K SOC REVF
ATMEGA128RFR2-ZF
功能描述:IC RF TXRX+MCU 802.15.4 64-VFQFN 制造商:microchip technology 系列:- 包装:托盘 零件状态:在售 类型:TxRx + MCU 射频系列/标准:802.15.4 协议:Zigbee? 调制:DSSS， O-QPSK 频率:2.4GHz 数据速率（最大值）:2Mbps 功率 - 输出:3.5dBm 灵敏度:-100dBm 存储容量:128kB 闪存，4kB EEPROM，16kB SRAM 串行接口:I2C，JTAG，SPI，USART GPIO:35 电压 - 电源:1.8 V ~ 3.6 V 电流 - 接收:5mA ~ 12.5mA 电流 - 传输:8mA ~ 14.5mA 工作温度:-40°C ~ 125°C 封装/外壳:64-VFQFN 裸露焊盘 标准包装:260
ATMEGA128RFR2-ZU
制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC IND 85C - Bulk
ATMEGA128RFR2-ZUR
制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC 85C T&R - Tape and Reel
ATMEGA128RZAV-8AU
功能描述:射频微控制器 - MCU AVR Z-Link Bundle RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:Si100x 数据总线宽度:8 bit 最大时钟频率:24 MHz 程序存储器大小:64 KB 数据 RAM 大小:4 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LGA-42 安装风格:SMD/SMT 封装:Tube
ATMEGA128RZAV-8MU
功能描述:射频微控制器 - MCU AVR Z-Link Bundle RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:Si100x 数据总线宽度:8 bit 最大时钟频率:24 MHz 程序存储器大小:64 KB 数据 RAM 大小:4 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LGA-42 安装风格:SMD/SMT 封装:Tube