參數(shù)資料
型號(hào): MC68L11F1CFN3
廠商: FREESCALE SEMICONDUCTOR INC
元件分類: 微控制器/微處理器
英文描述: 8-BIT, EEPROM, MICROCONTROLLER, PQCC68
封裝: PLASTIC, LCC-68
文件頁(yè)數(shù): 165/174頁(yè)
文件大?。?/td> 981K
代理商: MC68L11F1CFN3
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)第151頁(yè)第152頁(yè)第153頁(yè)第154頁(yè)第155頁(yè)第156頁(yè)第157頁(yè)第158頁(yè)第159頁(yè)第160頁(yè)第161頁(yè)第162頁(yè)第163頁(yè)第164頁(yè)當(dāng)前第165頁(yè)第166頁(yè)第167頁(yè)第168頁(yè)第169頁(yè)第170頁(yè)第171頁(yè)第172頁(yè)第173頁(yè)第174頁(yè)
MOTOROLA
SERIAL COMMUNICATIONS INTERFACE
MC68HC11F1
7-4
TECHNICAL DATA
7.4 Wakeup Feature
The wakeup 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 wakeup are available: idle-line wakeup and address-mark wakeup.
During idle-line wakeup, a sleeping receiver awakens as soon as the RxD line be-
comes idle. In the address-mark wakeup, 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 wakeup 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, or mark).
The first character of each message is an addressing character (MSB = 1). All receiv-
ers in the system evaluate this character to determine if the remainder of the message
is directed toward this particular receiver. As soon as a receiver determines that a
message is not intended for it, the receiver activates the RWU function by using a soft-
ware 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 begins, 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 al-
lows 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.
相關(guān)PDF資料
PDF描述
MC68HC11F1CFN3R2 8-BIT, EEPROM, 3 MHz, MICROCONTROLLER, PQCC68
MC68HC11F1CFN3R2 8-BIT, EEPROM, 3 MHz, MICROCONTROLLER, PQCC68
MC68SZ328VH66V 66 MHz, RISC PROCESSOR, PBGA196
MC74F2970N DRAM CONTROLLER, PDIP24
MC908GP32CFBR2 8-BIT, FLASH, 8.2 MHz, MICROCONTROLLER, PQFP44
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68L11F1CFNE3 功能描述:8位微控制器 -MCU 8B MCU 1KRAM 512BYTES 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
MC68L11K1FN2R2 制造商:Motorola Inc 功能描述:
MC68L11K1FUE2 功能描述:8位微控制器 -MCU 8B MCU L-VOLTAGE-EPP 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
MC68L711E9FN2 制造商:Rochester Electronics LLC 功能描述:- Bulk
MC68L711E9FNE2 功能描述:8位微控制器 -MCU 8B MCU LO VOLTAGE 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