參數(shù)資料
型號: MR83C154XXX-25P883
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, CQCC44
封裝: LCC-44
文件頁數(shù): 4/80頁
文件大小: 5152K
代理商: MR83C154XXX-25P883
196
2466T–AVR–07/10
ATmega16(L)
The upper seven bits are the address to which the Two-wire Serial Interface will respond when
addressed by a Master. If the LSB is set, the TWI will respond to the general call address ($00),
otherwise it will ignore the general call address.
TWEN must be written to one to enable the TWI. The TWEA bit must be written to one to enable
the acknowledgement of the device’s own Slave address or the general call address. TWSTA
and TWSTO must be written to zero.
When TWAR and TWCR have been initialized, the TWI waits until it is addressed by its own
Slave address (or the general call address if enabled) followed by the data direction bit. If the
direction bit is “1” (read), the TWI will operate in ST mode, otherwise SR mode is entered. After
its own Slave address and the write bit have been received, the TWINT Flag is set and a valid
status code can be read from TWSR. The status code is used to determine the appropriate soft-
ware action. The appropriate action to be taken for each status code is detailed in Table 77. The
Slave Transmitter mode may also be entered if arbitration is lost while the TWI is in the Master
mode (see state $B0).
If the TWEA bit is written to zero during a transfer, the TWI will transmit the last byte of the trans-
fer. State $C0 or state $C8 will be entered, depending on whether the Master Receiver transmits
a NACK or ACK after the final byte. The TWI is switched to the not addressed Slave mode, and
will ignore the Master if it continues the transfer. Thus the Master Receiver receives all “1” as
serial data. State $C8 is entered if the Master demands additional data bytes (by transmitting
ACK), even though the Slave has transmitted the last byte (TWEA zero and expecting NACK
from the Master).
While TWEA is zero, the TWI does not respond to its own Slave address. However, the Two-
wire Serial Bus is still monitored and address recognition may resume at any time by setting
TWEA. This implies that the TWEA bit may be used to temporarily isolate the TWI from the Two-
wire Serial Bus.
In all sleep modes other than Idle mode, the clock system to the TWI is turned off. If the TWEA
bit is set, the interface can still acknowledge its own Slave address or the general call address
by using the Two-wire Serial Bus clock as a clock source. The part will then wake up from sleep
and the TWI will hold the SCL clock will low during the wake up and until the TWINT Flag is
cleared (by writing it to one). Further data transmission will be carried out as normal, with the
AVR clocks running as normal. Observe that if the AVR is set up with a long start-up time, the
SCL line may be held low for a long time, blocking other data transmissions.
Note that the Two-wire Serial Interface Data Register – TWDR does not reflect the last byte
present on the bus when waking up from these sleep modes.
TWCR
TWINT
TWEA
TWSTA
TWSTO
TWWC
TWEN
TWIE
Value
0
100
01
0
X
相關(guān)PDF資料
PDF描述
MS80C51-12D 8-BIT, MROM, 12 MHz, MICROCONTROLLER, PQCC44
MT80C51T-16R 8-BIT, MROM, 16 MHz, MICROCONTROLLER, PQFP44
MD80C32E-20SC 8-BIT, 20 MHz, MICROCONTROLLER, CDIP40
MC80C52XXX-16SHXXX 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CDIP40
MD80C52EXXX-20 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CDIP40
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MR850 功能描述:整流器 3.0 Amp 50 Volt 150ns RoHS:否 制造商:Vishay Semiconductors 產(chǎn)品:Standard Recovery Rectifiers 配置: 反向電壓:100 V 正向電壓下降: 恢復(fù)時間:1.2 us 正向連續(xù)電流:2 A 最大浪涌電流:35 A 反向電流 IR:5 uA 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DO-221AC 封裝:Reel
MR850 _AY _10001 制造商:PanJit Touch Screens 功能描述:
MR850 R0 制造商:SKMI/Taiwan 功能描述:Diode Switching 50V 3A 2-Pin DO-201AD T/R
MR850_ R2 _10001 制造商:PanJit Touch Screens 功能描述:
MR850_09 制造商:PANJIT 制造商全稱:Pan Jit International Inc. 功能描述:SOFT RECOVERY, FAST SWITCHING PLASTIC RECTIFIER