參數(shù)資料
型號(hào): MC68711D3CFBE2
廠商: Freescale Semiconductor
文件頁數(shù): 93/124頁
文件大?。?/td> 0K
描述: IC MCU 8BIT 44-QFP
標(biāo)準(zhǔn)包裝: 96
系列: HC11
核心處理器: HC11
芯體尺寸: 8-位
速度: 2MHz
連通性: SCI,SPI
外圍設(shè)備: POR,WDT
輸入/輸出數(shù): 26
程序存儲(chǔ)器容量: 4KB(4K x 8)
程序存儲(chǔ)器類型: OTP
RAM 容量: 192 x 8
電壓 - 電源 (Vcc/Vdd): 4.5 V ~ 5.5 V
振蕩器型: 內(nèi)部
工作溫度: -40°C ~ 85°C
封裝/外殼: 44-QFP
包裝: 托盤
SERIAL COMMUNICATIONS INTERFACE
7-4
TECHNICAL DATA
7.4 Wake-up Feature
The wake-up feature reduces SCI service overhead in multiple receiver systems. Soft-
ware for each receiver evaluates the first character of each message. The receiver is
placed in wakeup mode by writing a one to the RWU bit in the SCCR2 register. While
RWU is one, all of the receiver-related status flags (RDRF, IDLE, OR, NF, and FE) are
inhibited (cannot become set). Although RWU can be cleared by a software write to
SCCR2, to do so would be unusual. Normally RWU is set by software and is cleared
automatically with hardware. Whenever a new message begins, logic alerts the sleep-
ing receivers to wake up and evaluate the initial character of the new message.
Two methods of wake-up are available: idle line wake-up and address mark wake-up.
During idle line wake-up, a sleeping receiver awakens as soon as the RxD line be-
comes idle. In the address mark wake-up, logic one in the most significant bit (MSB)
of a character wakes up all sleeping receivers.
7.4.1 Idle-Line Wakeup
To use the receiver wake-up method, establish a software addressing scheme to allow
the transmitting devices to direct a message to individual receivers or to groups of re-
ceivers. This addressing scheme can take any form as long as all transmitting and re-
ceiving devices are programmed to understand the same scheme. Because the
addressing information is usually the first frame(s) in a message, receivers that are not
part of the current task do not become burdened with the entire set of addressing
frames. All receivers are awake (RWU = 0) when each message begins. As soon as
a receiver determines that the message is not intended for it, software sets the RWU
bit (RWU = 1), which inhibits further flag setting until the RxD line goes idle at the end
of the message. As soon as an idle line is detected by receiver logic, hardware auto-
matically clears the RWU bit so that the first frame of the next message can be re-
ceived. This type of receiver wakeup requires a minimum of one idle-line frame time
between messages, and no idle time between frames in a message.
7.4.2 Address-Mark Wakeup
The serial characters in this type of wakeup consist of seven (eight if M = 1) information
bits and an MSB, which indicates an address character (when set to one — mark). The
first character of each message is an addressing character (MSB = 1). All receivers in
the system evaluate this character to determine if the remainder of the message is di-
rected toward this particular receiver. As soon as a receiver determines that a mes-
sage is not intended for it, the receiver activates the RWU function by using a software
write to set the RWU bit. Because setting RWU inhibits receiver-related flags, there is
no further software overhead for the rest of this message. When the next message be-
gins, its first character has its MSB set, which automatically clears the RWU bit and
enables normal character reception. The first character whose MSB is set is also the
first character to be received after wakeup because RWU gets cleared before the stop
bit for that frame is serially received. This type of wakeup allows messages to include
gaps of idle time, unlike the idle-line method, but there is a loss of efficiency because
of the extra bit time for each character (address bit) required for all characters.
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.
相關(guān)PDF資料
PDF描述
VE-B11-CU-F4 CONVERTER MOD DC/DC 12V 200W
MC68711E20CFNE3 IC MCU 8BIT 52-PLCC
HCE103MBCDJ0KR CAP CER 10000PF 3KV 20% RADIAL
MC68711E20CFUE2 IC MCU 8BIT 64-QFP
HCE103MBCDF0KR CAP CER 10000PF 3KV 20% RADIAL
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68711E20CFNE2 功能描述:8位微控制器 -MCU 8B 20K EPROM 768RAM 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT
MC68711E20CFNE2 制造商:Freescale Semiconductor 功能描述:8-Bit Microcontroller IC
MC68711E20CFNE3 功能描述:8位微控制器 -MCU 8B 20K EPROM 768RAM 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT
MC68711E20CFNE4 功能描述:8位微控制器 -MCU 8B 20K EPROM 768RAM 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT
MC68711E20CFUE2 功能描述:IC MCU 8BIT 64-QFP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:HC11 標(biāo)準(zhǔn)包裝:1 系列:AVR® ATmega 核心處理器:AVR 芯體尺寸:8-位 速度:16MHz 連通性:I²C,SPI,UART/USART 外圍設(shè)備:欠壓檢測(cè)/復(fù)位,POR,PWM,WDT 輸入/輸出數(shù):32 程序存儲(chǔ)器容量:32KB(16K x 16) 程序存儲(chǔ)器類型:閃存 EEPROM 大小:1K x 8 RAM 容量:2K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 5.5 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 8x10b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 125°C 封裝/外殼:44-TQFP 包裝:剪切帶 (CT) 其它名稱:ATMEGA324P-B15AZCT