参数资料
型号: 668-0003-C
厂商: Rabbit Semiconductor
文件页数: 36/228页
文件大小: 0K
描述: IC CPU RABBIT2000 30MHZ 100PQFP
标准包装: 100
系列: Rabbit 2000
处理器类型: Rabbit 2000 8-位
速度: 30MHz
电压: 2.7V,3V,3.3V,5V
安装类型: 表面贴装
封装/外壳: 100-BQFP
供应商设备封装: 100-PQFP(14x20)
包装: 托盘
其它名称: 316-1004
668-0003
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页当前第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页第109页第110页第111页第112页第113页第114页第115页第116页第117页第118页第119页第120页第121页第122页第123页第124页第125页第126页第127页第128页第129页第130页第131页第132页第133页第134页第135页第136页第137页第138页第139页第140页第141页第142页第143页第144页第145页第146页第147页第148页第149页第150页第151页第152页第153页第154页第155页第156页第157页第158页第159页第160页第161页第162页第163页第164页第165页第166页第167页第168页第169页第170页第171页第172页第173页第174页第175页第176页第177页第178页第179页第180页第181页第182页第183页第184页第185页第186页第187页第188页第189页第190页第191页第192页第193页第194页第195页第196页第197页第198页第199页第200页第201页第202页第203页第204页第205页第206页第207页第208页第209页第210页第211页第212页第213页第214页第215页第216页第217页第218页第219页第220页第221页第222页第223页第224页第225页第226页第227页第228页
124
Rabbit 2000 Microprocessor User’s Manual
12.3 Transmit Serial Data Timing
On transmit, if the interrupts are enabled, an interrupt is requested when the transmit regis-
ter becomes empty and, in addition, an interrupt occurs when the shift register and trans-
mit register both become empty, that is, when the transmitter becomes idle. When the
transmit data register contains data and the shift register finishes sending data, the data bits
are clocked from the transmit register to the shift register, and the shift register is never
idle. The interrupt request is cleared either by writing to the data register or by writing to
the status register (which does not affect the status register). The data register normally is
clocked into the shift register each time the shift register finishes sending data, leaving the
data register empty. This causes an interrupt request. The interrupt routine normally
answers the interrupt before the shift register runs dry (9 to 11 baud clocks, depending on
the mode of operation). The interrupt routine stores the next data item in the data register,
clearing the interrupt request and supplying the next data bits to be sent. When all the
characters have been sent, the interrupt service routine answers the interrupt once the data
register becomes empty. Since it has no more data, it clears the interrupt request by storing
to the status register. At this point the routine should check if the shift register is empty;
normally it won’t be. If it is, because the interrupt was answered late, the interrupt routine
should do any final cleanup and store to the status register again in case the shift register
became empty after the pending interrupt is cleared. Normally, though, the interrupt ser-
vice routine will return and there will be a final interrupt to give the routine a chance to
disable the output buffers, as in the case for RS-485 transmission.
12.4 Receive Serial Data Timing
When the receiver is ready to receive data, a falling edge indicates that a start bit must be
detected. The falling edge is detected as a different Rx input between two different clocks,
the clock being 16x the baud rate. Once the start bit has been detected, data bits are sam-
pled at the middle of each data bit and are shifted into the receive shift register. After 7 or
8 data bits have been received, the next bit will be either a 9th (8th) address bit, or a stop
bit will be sampled. If the Rx line is low, it is an address bit and the address bit received bit
in the status register will be enabled. If an address bit is detected, the receiver will attempt
to sample the stop bit. If the line is high when sampled, it is a stop bit and a new scan for a
new start bit will begin after the sample point. At the same time, the data bits are trans-
ferred into the receive data register and an interrupt, if enabled, is requested.
On receive, an interrupt is requested when the receiver data register has data. This happens
when data bits are transferred from the receive shift register to the data register. This also
sets bit 7 of the status register. The interrupt request and bit 7 are cleared when the data
register is read.
An interrupt is requested if bit 7 is high. The interrupt is requested on the edge of the trans-
mitter data register becoming empty or the transmitter shift register becoming empty. The
transmitter interrupt is cleared by writing to the status register or to the data register.
On receive, the scan for the next start bit starts immediately after the stop bit is detected.
The stop bit is normally detected at a sample clock that nominally occurs in the center of
the stop bit. If there is a 9th (8th) address bit, the stop bit follows that bit.
相关PDF资料
PDF描述
668-0011 IC MPU RABIT3000A 55.5MHZ128LQFP
6PAIC3106IRGZRQ1 IC AUDIO CODEC STEREO 48-QFN
70001851 DEVICE SERVER 1PORT SRL-ETHERNET
73M1822-IM/F MICRODAA VOICE DATA/FAX 42-QFN
73M1866B-IM/F MICRODAA SGL PCM HIGHWAY 42-QFN
相关代理商/技术参数
参数描述
6680005578829 制造商: 功能描述: 制造商:undefined 功能描述:
6680008268807 制造商: 功能描述: 制造商:undefined 功能描述:
6680-00-882-0965 制造商: 功能描述: 制造商:undefined 功能描述:
6680008912796 制造商: 功能描述: 制造商:undefined 功能描述:
6680009296667 制造商: 功能描述: 制造商:undefined 功能描述: