The I2" />
參數(shù)資料
型號: PIC18F242-I/SO
廠商: Microchip Technology
文件頁數(shù): 105/134頁
文件大小: 0K
描述: IC MCU FLASH 8KX16 EE A/D 28SOIC
產(chǎn)品培訓模塊: Asynchronous Stimulus
8-bit PIC® Microcontroller Portfolio
標準包裝: 27
系列: PIC® 18F
核心處理器: PIC
芯體尺寸: 8-位
速度: 40MHz
連通性: I²C,SPI,UART/USART
外圍設(shè)備: 欠壓檢測/復位,LVD,POR,PWM,WDT
輸入/輸出數(shù): 23
程序存儲器容量: 16KB(8K x 16)
程序存儲器類型: 閃存
EEPROM 大小: 256 x 8
RAM 容量: 768 x 8
電壓 - 電源 (Vcc/Vdd): 4.2 V ~ 5.5 V
數(shù)據(jù)轉(zhuǎn)換器: A/D 5x10b
振蕩器型: 外部
工作溫度: -40°C ~ 85°C
封裝/外殼: 28-SOIC(0.295",7.50mm 寬)
包裝: 管件
配用: XLT28SO-1-ND - SOCKET TRANSITION 28SOIC 300MIL
其它名稱: PIC18F242I/SO
PIC16C9XX
DS30444E - page 72
1997 Microchip Technology Inc.
11.2.4
MULTI-MASTER
The I2C protocol allows a system to have more than
one master. This is called multi-master. When two or
more masters try to transfer data at the same time, arbi-
tration and synchronization occur.
11.2.4.1
ARBITRATION
Arbitration takes place on the SDA line, while the SCL
line is high. The master which transmits a high when the
other
master
transmits
a
low
loses
arbitration
(Figure 11-16), and turns off its data output stage. A
master which lost arbitration can generate clock pulses
until the end of the data byte where it lost arbitration.
When the master devices are addressing the same
device, arbitration continues into the data.
FIGURE 11-16: MULTI-MASTER
ARBITRATION
(TWO MASTERS)
Masters that also incorporate the slave function, and
have lost arbitration must immediately switch over to
slave-receiver mode. This is because the winning mas-
ter-transmitter may be addressing it.
Arbitration is not allowed between:
A repeated START condition
A STOP condition and a data bit
A repeated START condition and a STOP condi-
tion
Care needs to be taken to ensure that these conditions
do not occur.
transmitter 1 loses arbitration
DATA 1 SDA
DATA 1
DATA 2
SDA
SCL
11.2.4.2 Clock Synchronization
Clock synchronization occurs after the devices have
started
arbitration. This
is
performed
using
a
wired-AND connection to the SCL line. A high to low
transition on the SCL line causes the concerned
devices to start counting off their low period. Once a
device clock has gone low, it will hold the SCL line low
until its SCL high state is reached. The low to high tran-
sition of this clock may not change the state of the SCL
line, if another device clock is still within its low period.
The SCL line is held low by the device with the longest
low period. Devices with shorter low periods enter a
high wait-state, until the SCL line comes high. When the
SCL line comes high, all devices start counting off their
high periods. The rst device to complete its high period
will pull the SCL line low. The SCL line high time is
determined by the device with the shortest high period,
FIGURE 11-17: CLOCK SYNCHRONIZATION
CLK
1
CLK
2
SCL
wait
state
start counting
HIGH period
counter
reset
相關(guān)PDF資料
PDF描述
AT91SAM7S512-MU-999 IC MCU ARM7 512KB FLASH 64-VQFN
DSPIC33FJ32GS608-I/PT IC MCU/DSP 32KB FLASH 80TQFP
AT91SAM7XC256-CU-999 IC MCU ARM7 256KB FLASH 100TFBGA
AT91SAM7X256-CU-999 IC MCU ARM7 256KB FLASH 100TFBGA
DSPIC33FJ64MC802-E/SO IC DSPIC MCU/DSP 64K 28-SOIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC18F242T-E/SO 功能描述:8位微控制器 -MCU 40MHz 16KB Flash RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18F242T-I/SO 功能描述:8位微控制器 -MCU 16KB 768 RAM 23I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18F2431-E/ML 功能描述:8位微控制器 -MCU 16KB 768 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18F2431-E/MM 功能描述:8位微控制器 -MCU 16 KB FL 768 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18F2431-E/SO 功能描述:8位微控制器 -MCU 16KB 768 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT