參數(shù)資料
型號: Z85233
廠商: ZiLOG, Inc.
英文描述: The Zilog SCC Serial Communication Controller
中文描述: Zilog公司鱗癌的串行通信控制器
文件頁數(shù): 220/317頁
文件大?。?/td> 3201K
代理商: Z85233
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頁當(dāng)前第220頁第221頁第222頁第223頁第224頁第225頁第226頁第227頁第228頁第229頁第230頁第231頁第232頁第233頁第234頁第235頁第236頁第237頁第238頁第239頁第240頁第241頁第242頁第243頁第244頁第245頁第246頁第247頁第248頁第249頁第250頁第251頁第252頁第253頁第254頁第255頁第256頁第257頁第258頁第259頁第260頁第261頁第262頁第263頁第264頁第265頁第266頁第267頁第268頁第269頁第270頁第271頁第272頁第273頁第274頁第275頁第276頁第277頁第278頁第279頁第280頁第281頁第282頁第283頁第284頁第285頁第286頁第287頁第288頁第289頁第290頁第291頁第292頁第293頁第294頁第295頁第296頁第297頁第298頁第299頁第300頁第301頁第302頁第303頁第304頁第305頁第306頁第307頁第308頁第309頁第310頁第311頁第312頁第313頁第314頁第315頁第316頁第317頁
Application Note
SCC in Binary Synchronous Communications
6-85
9
TRANSMIT OPERATION
To transmit a block of data, the main program calls up the
transmit data routine. With this routine, each message
block to be transmitted is stored in memory, beginning with
location ‘TBUF’. The number of characters contained in
each block is determined by the value assigned to the
‘COUNT’ parameter in the main module.
To prepare for transmission, the routine enables the
transmitter and selects the Wait On Transmit function; it
then enables the wait function. The Wait On Transmit
function indicates to the CPU whether or not the Z-SCC is
ready to accept data from the CPU. If the CPU attempts to
send data to the Z-SCC when the transmit buffer is full, the
Z-SCC asserts its Wait line and keeps it Low until the
buffer is empty. In response, the CPU extends its I/O
cycles until the Wait line goes inactive, indicating that the
Z-SCC is ready to receive data.
The CRC generator is reset and the Transmit CRC bit is
enabled before the first character is sent, thus including all
the characters sent to the Z-SCC in the CRC calculation,
until the Transmit CRC bit is disabled. CRC generation can
be disabled for a particular character by resetting the
TxCRC bit within the transmit routine. In this application,
however, the Transmit CRC bit is not disabled, so that all
characters sent to the Z-SCC are included in the CRC
calculation.
The Z-SCC’s transmit underrun/EOM latch must be reset
sometime after the first character is transmitted by writing
a Reset Tx Underrun/EOM command to WR0. When this
latch is reset, the Z-SCC automatically appends the CRC
characters to the end of the message in the case of an
underrun condition.
Finally, a five-character delay is introduced at the end of
the transmission, which allows the Z-SCC sufficient time to
transmit the last data byte, two CRC characters, and two
sync characters before disabling the transmitter.
RECEIVE OPERATION
Once the Z-SCC is initialized, it can be prepared to receive
data. First, the receiver is enabled, placing the Z-SCC in
Hunt mode and thus setting the Sync/Hunt bit in status
register RR0 to 1. In Hunt mode, the receiver is idle except
that it searches the incoming data stream for a sync
character match. When a match is discovered between the
incoming data stream and the sync characters stored in
WR6 and WR7, the receiver exits the Hunt mode, resetting
the Sync/Hunt bit in status register RR0 and establishing
the Receive Interrupt On First Character mode. Upon
detection of the receive interrupt, the CPU generates an
Interrupt Acknowledge cycle. The Z-SCC sends to the
CPU vector %2C, which points to the location in the
Program Status Area from which the receive interrupt
service routine is accessed.
The receive data routine is called from within the receive
interrupt service routine. While expecting a block of data,
the Wait On Receive function is enabled. Receive data
buffer RR8 is read, and the characters are stored in
memory locations starting at RBUF. The Start of Text
(%02) character is discarded. After the End of
Transmission character (%04) is received, the two CRC
bytes are read. The result of the CRC check becomes valid
two characters later, at which time, RR1 is read and the
CRC error bit is checked. If the bit is zero, the message
received can be assumed correct; if the bit is 1, an error in
the transmission is indicated.
Before leaving the interrupt service routine, Reset Highest
IUS (Interrupt Under Service), Enable Interrupt on Next
Receive Character, and Enter Hunt Mode commands are
issued to the Z-SCC.
If a receive overrun error is made, a special condition
interrupt occurs. The Z-SCC presents the vector %2E to
the CPU, and the service routine located at address
%447A is executed. The Special Receive Condition
register RR1 is read to determine which error occurred.
Appropriate action to correct the error should be taken by
the user at this point. Error Reset and Reset Highest IUS
commands are given to the Z-SCC before returning to the
main program so that the other lower priority interrupts can
occur.
SOFTWARE
Software routines are presented in the following pages.
These routines can be modified to include various versions of
Bisync protocol, such as Transparent and Nontransparent
modes. Encoding methods other than NRZ (e.g., NRZI, FM0,
FM1) can also be used by modifying WR10.
UM010901-0601
相關(guān)PDF資料
PDF描述
Z8602 CAP 0.033UF 100V 10% X7R AXIAL TR-14
Z860201PSC 8-BIT MICROCONTROLLER
Z860202PSC Leaded Cartridge Fuse; Current Rating:600mA; Voltage Rating:250V; Fuse Terminals:Axial Lead; Fuse Type:Time Delay; Voltage Rating:250V; Body Material:Glass; Diameter:4.7mm; Fuse Size/Group:5 x 15 mm; Leaded Process Compatible:Yes RoHS Compliant: Yes
Z860203PSC 8-BIT MICROCONTROLLER
Z86116 CAP 0.033UF 100V 10% X7R AXIAL TR-14
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
Z8523310ASG 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 10 MHZ CMOS ESCC/2 RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
Z8523310FSC 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 10MHz CMOS ESCC/2 RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
Z8523310FSC00TR 功能描述:IC ESCC 44QFP RoHS:否 類別:集成電路 (IC) >> 接口 - 控制器 系列:EMSCC™ 標(biāo)準(zhǔn)包裝:4,900 系列:- 控制器類型:USB 2.0 控制器 接口:串行 電源電壓:3 V ~ 3.6 V 電流 - 電源:135mA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:36-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:36-QFN(6x6) 包裝:* 其它名稱:Q6396337A
Z8523310FSG 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 10MHz CMOS ESCC/2 RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
Z8523310VSC 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 10MHz CMOS ESCC/2 RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray