參數(shù)資料
型號： MC80C52EXXX-25/883:D
廠商： ATMEL CORP
元件分類： 微控制器/微處理器
英文描述： 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CDIP40
封裝： 0.600 INCH, SIDE BRAZED, DIP-40
文件頁數(shù)： 24/141頁
文件大?。?/td> 7628K
204
8021G–AVR–03/11
ATmega329P/3290P
Figure 20-5. Two-wire Mode, Typical Timing Diagram
Referring to the timing diagram (Figure 20-5.), a bus transfer involves the following steps:
1.
The a start condition is generated by the Master by forcing the SDA low line while the
SCL line is high (A). SDA can be forced low either by writing a zero to bit 7 of the Shift
Register, or by setting the corresponding bit in the PORT Register to zero. Note that the
Data Direction Register bit must be set to one for the output to be enabled. The slave
device’s start detector logic (Figure 20-6.) detects the start condition and sets the USISIF
Flag. The flag can generate an interrupt if necessary.
2.
In addition, the start detector will hold the SCL line low after the Master has forced an
negative edge on this line (B). This allows the Slave to wake up from sleep or complete
its other tasks before setting up the Shift Register to receive the address. This is done by
clearing the start condition flag and reset the counter.
3.
The Master set the first bit to be transferred and releases the SCL line (C). The Slave
samples the data and shift it into the Serial Register at the positive edge of the SCL
clock.
4.
After eight bits are transferred containing slave address and data direction (read or
write), the Slave counter overflows and the SCL line is forced low (D). If the slave is not
the one the Master has addressed, it releases the SCL line and waits for a new start
condition.
5.
If the Slave is addressed it holds the SDA line low during the acknowledgment cycle
before holding the SCL line low again (i.e., the Counter Register must be set to 14 before
releasing SCL at (D)). Depending of the R/W bit the Master or Slave enables its output. If
the bit is set, a master read operation is in progress (i.e., the slave drives the SDA line)
The slave can hold the SCL line low after the acknowledge (E).
6.
Multiple bytes can now be transmitted, all in same direction, until a stop condition is given
by the Master (F). Or a new start condition is given.
If the Slave is not able to receive more data it does not acknowledge the data byte it has last
received. When the Master does a read operation it must terminate the operation by force the
acknowledge bit low after the last byte transmitted.
Figure 20-6. Start Condition Detector, Logic Diagram
P
S
ADDRESS
1 - 7
8
9
R/W
ACK
1 - 8
9
DATA
ACK
1 - 8
9
DATA
SDA
SCL
A
B
D
E
C
F
SDA
SCL
Write( USISIF)
CLOCK
HOLD
USISIF
DQ
CLR
DQ
CLR
相關(guān)PDF資料
PDF描述
MR80C52EXXX-12/883:R 8-BIT, MROM, 12 MHz, MICROCONTROLLER, CQCC44
MC80C52XXX-16SHXXX:D 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CDIP40
MQ80C52TXXX-30SBR 8-BIT, MROM, 30 MHz, MICROCONTROLLER, CQFP44
MR83C154XXX-25/883D 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CQCC44
MR83C154CXXX-25P883R 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CQCC44
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC80D21000G 制造商:COR 功能描述:RN
MC80F0104 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS
MC80F0104B 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS
MC80F0104D 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS
MC80F0204 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS
發(fā)布緊急采購，3分鐘左右您將得到回復。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*