參數(shù)資料
型號(hào): MC68HC705BD3
廠商: Motorola, Inc.
英文描述: 8-Bit Microcontroller Units (MCU).(8位微控制器)
中文描述: 8位微控制器單元(MCU)。(8位微控制器)
文件頁(yè)數(shù): 50/112頁(yè)
文件大?。?/td> 676K
代理商: MC68HC705BD3
MOTOROLA
7-4
MC68HC05BD3
M-BUS SERIAL INTERFACE
7
7.2.3
Data Transfer
Once a successful slave addressing is achieved, the data transfer can proceed byte by byte in a
direction specified by the R/W bit sent by the calling master.
Each data byte is 8 bits long. Data can be changed only when SCL is low and must be held stable
when SCL is high as shown in Figure 7-2. One clock pulse is for one bit of data transfer, MSB is
transferred first. Each data byte has to be followed by an acknowledge bit. Hence, one complete
data byte transfer requires 9 clock pulses.
If the slave receiver does not acknowledge the master, the SDA line should be left high by the
slave, the master can then generate a STOP signal to abort the data transfer or a START signal
(repeated START) to commence a new calling.
If the master receiver does not acknowledge the slave transmitter after one byte transmission, it
means an “end of data” to the slave. The slave shall release the SDA line for the master to
generate STOP or START signal.
7.2.4
Repeated START Signal
As shown in Figure 7-2, a repeated START signal is to generate a START signal without first
generating a STOP signal to terminate the communication. This is used by the master to
communicate with another slave or with the same slave in a different mode (transmit/receive
mode) without releasing the bus.
7.2.5
STOP Signal
The master can terminate the communication by generating a STOP signal to free the bus.
However, the master may generate a START signal followed by a calling command without
generating a STOP signal first. This is called repeat START. A STOP signal is defined as a low to
high transition of SDA while SCL is at a logical high; see Figure 7-2.
7.2.6
Arbitration Procedure
This interface circuit is a true multi-master system which allows more than one master to be
connected. If two or more masters try to control the bus at the same time, a clock synchronization
procedure determines the bus clock. The clock low period is equal to the longest clock low period
among the masters; and the clock high period is the shortest among the masters. A data
arbitration procedure determines the priority. A master will lose arbitration if it transmits a logic “1”
while the others transmit logic “0”, the losing master will immediately switch over to slave receive
mode and stops its data and clock outputs. The transition from master to slave mode will not
generate a STOP condition. Meanwhile, a software bit will be set by hardware to indicate loss of
arbitration.
TPG
相關(guān)PDF資料
PDF描述
MC68HC05C4 8-Bit Microcontroller Units (MCU).(8位微控制器)
MC68HC05C5 8-Bit Microcontroller Units (MCU).(8位微控制器)
MC68HC05C8A Microcontrollers
MC68HC05C9A 8-Bit Microcontroller(8位微控制器)
MC68HCL05C9A 8-Bit Microcontroller(8位微控制器)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68HC705BD3P 制造商:Motorola 功能描述:MOTOROLA NXC4C
MC68HC705BD7P1 制造商:Rochester Electronics LLC 功能描述:- Bulk
MC68HC705C4ACP 制造商:Freescale Semiconductor 功能描述:
MC68HC705C8AB 功能描述:IC MCU 8K OTP 2.1MHZ 42-SDIP RoHS:否 類(lèi)別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:HC05 標(biāo)準(zhǔn)包裝:250 系列:56F8xxx 核心處理器:56800E 芯體尺寸:16-位 速度:60MHz 連通性:CAN,SCI,SPI 外圍設(shè)備:POR,PWM,溫度傳感器,WDT 輸入/輸出數(shù):21 程序存儲(chǔ)器容量:40KB(20K x 16) 程序存儲(chǔ)器類(lèi)型:閃存 EEPROM 大小:- RAM 容量:6K x 16 電壓 - 電源 (Vcc/Vdd):2.25 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 6x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 125°C 封裝/外殼:48-LQFP 包裝:托盤(pán) 配用:MC56F8323EVME-ND - BOARD EVALUATION MC56F8323
MC68HC705C8ACB 制造商:Rochester Electronics LLC 功能描述:HCO5 CORE + 8K RAM + EPR - Bulk