參數(shù)資料
型號: MC908QL4M
廠商: Motorola, Inc.
英文描述: Microcontrollers
中文描述: 微控制器
文件頁數(shù): 157/222頁
文件大?。?/td> 2861K
代理商: MC908QL4M
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁第156頁當(dāng)前第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁第177頁第178頁第179頁第180頁第181頁第182頁第183頁第184頁第185頁第186頁第187頁第188頁第189頁第190頁第191頁第192頁第193頁第194頁第195頁第196頁第197頁第198頁第199頁第200頁第201頁第202頁第203頁第204頁第205頁第206頁第207頁第208頁第209頁第210頁第211頁第212頁第213頁第214頁第215頁第216頁第217頁第218頁第219頁第220頁第221頁第222頁
Initialization/Application Information
MC68HC908QL4 MC68HC908QL3 MC68HC908QL2 Data Sheet, Rev. 4
Freescale Semiconductor
157
checksum on the first data byte. Using CHKMOD in this way allows the SLIC to receive messages with
either method of data consistency check and change on a frame-by-frame basis. If a system uses both
types of data consistency checking methods, the software must simply change the setting of this bit based
on the identifier of each message. If the network only uses one type of check, CHKMOD can be set as a
constant value in the user’s code. If CHKMOD is not written on each frame, care must be taken not to
accidentally modify the bit when writing the data length and TXGO bits. This is especially true if using C
code without carefully inspecting the output of the compiler and assembler.
The control bits and data length code are contained in one register, allowing the user to maximize the
efficiency of the identifier processing by writing a single byte value to indicate the nature of the message
frame. This allows very efficient identifier processing code, which is important in a command frame, as
the master node can be sending data immediately following the identifier byte which might be as little as
one byte in length. The SLIC module uses a separate internal storage area for the incoming data bytes,
so there is no danger of losing incoming data, but the user should spend as little time as possible within
the ISR to ensure that the application or other ISRs are able to use the majority of the CPU bandwidth.
The identifier must be processed in a maximum of 2 byte times on the LIN bus to ensure that the ISR
completes before the checksum would be received for the shortest possible message. This should be
easily achievable, as the only operations required are to read SLCID and look up the checksum method,
data length, and command/request state of that identifier, then write that value to the SLCDLC. This can
be easily streamlined in code with a lookup table of identifiers and corresponding SLCDLC bytes.
NOTE
Once the ID is decoded for a message header and a length code written to
SLCDLC, the SLIC is expecting that number of bytes to be received. If the
SLIC module doesn't receive the number of bytes indicated in the SLCDLC
register, it will continue to look for data bytes. If another message header
begins, a byte framing error will trigger on the break symbol of that second
message. The second message will still properly generate an ID received
interrupt, but the byte framing error prior to this is an indication to the
application that the previous message was not properly handled and should
be discarded.
14.9.8.2 Extended Command Message Frames
Handling of extended frames is very similar to handling of standard frames, providing that the length is
less than or equal to 64 bytes. Because the SLIC module can only receive 8 bytes at a time, the receive
buffer must be emptied periodically for long message frames. This is not standard LIN operation, and is
likely only to be used for downloading calibration data or reprogramming FLASH devices in a factory or
service facility, so the added steps required for processing are not as critical to performance. During these
types of operations, the application code is likely very limited in scope and special adjustments can be
made to compensate for added message processing time.
For extended command frames, the data length is still written one time at the time the identifier is
decoded, along with the TXGO and CHKMOD bits. When this is done, a software counter must also be
initialized to keep track of how many bytes are expected to be received in the message frame. The ISR
completes, clearing the SLCF flag, and resumes application execution. The SLIC will generate an
interrupt, if unmasked, after 8 bytes are received or an error is detected. At this interrupt, the SLCSV will
indicate an error condition (in case of byte framing error, idle bus) or that the receive buffer is full. If the
data is successfully received, the user must then empty the buffer by reading SLCD7-SLCD0 and then
subtract 8 from the software byte count. When this software counter reaches 8 or fewer, the remaining
相關(guān)PDF資料
PDF描述
MC908QL4V Microcontrollers
MC912DG128x microcontroller unit 16BIT DEVICE
MC68HC912DG128A microcontroller unit 16BIT DEVICE
MC912DG128A microcontroller unit 16BIT DEVICE
MC68HC912DT128A microcontroller unit 16BIT DEVICE
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC908QL4MDT 功能描述:IC MCU 8BIT 4K FLASH 16-TSSOP RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:HC08 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 程序存儲器容量:40KB(20K x 16) 程序存儲器類型: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 配用:MC56F8323EVME-ND - BOARD EVALUATION MC56F8323
MC908QL4MDTE 功能描述:8位微控制器 -MCU NITRON LINE 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 最大時鐘頻率:50 MHz 程序存儲器大小: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
MC908QL4MDTE 制造商:Freescale Semiconductor 功能描述:Microcontroller
MC908QL4MDTER 功能描述:8位微控制器 -MCU NITRON LINE 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 最大時鐘頻率:50 MHz 程序存儲器大小: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
MC908QL4MDW 功能描述:IC MCU 8BIT 4K FLASH 16-SOIC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:HC08 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 程序存儲器容量:40KB(20K x 16) 程序存儲器類型: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 配用:MC56F8323EVME-ND - BOARD EVALUATION MC56F8323