A language monitor provides a full duplex communications path between the print spooler and bi-directional printers that are capable of providing software-accessible status information and adds printer control information, such as commands defined by a printer job language, to the data stream s.
This design is a universal register which can be used as a straightforward storage register, a bi-directional shift register, an up counter and a down counter.
HIGH SPEED 8051 μC CORE
- Pipe-lined Instruction Architecture; Executes 70% of Instructions in 1 or 2
System Clocks
- Up to 25MIPS Throughput with 25MHz System Clock
- 22 Vectored Interrupt Sources
MEMORY
- 4352 Bytes Internal Data RAM (256 + 4k)
- 64k Bytes In-System Programmable FLASH Program Memory
- External Parallel Data Memory Interface – up to 5Mbytes/sec
DIGITAL PERIPHERALS
- 64 Port I/O; All are 5V tolerant
- Hardware SMBusTM (I2CTM Compatible), SPITM, and Two UART Serial
Ports Available Concurrently
- Programmable 16-bit Counter/Timer Array with 5 Capture/Compare
Modules
- 5 General Purpose 16-bit Counter/Timers
- Dedicated Watch-Dog Timer; bi-directional Reset
CLOCK SOURCES
- Internal Programmable Oscillator: 2-to-16MHz
- External Oscillator: Crystal, RC, C, or Clock
- Real-Time Clock Mode using Timer 3 or PCA
SUPPLY VOLTAGE ........................ 2.7V to 3.6V
- Typical Operating Current: 10mA @ 25MHz
- Multiple Power Saving Sleep and Shutdown Modes
100-Pin TQFP (64-Pin Version Available)
Temperature Range: –40°C to +85°C
基于幅移鍵控技術(shù)ASK（Amplitude-Shift Keying），以C8051F340單片機(jī)作為監(jiān)測(cè)終端控制器，C8051F330D單片機(jī)作為探測(cè)節(jié)點(diǎn)控制器，采用半雙工的通信方式，通過(guò)監(jiān)控終端和探測(cè)節(jié)點(diǎn)的無(wú)線收發(fā)電路，實(shí)現(xiàn)數(shù)據(jù)的雙向無(wú)線傳輸。收發(fā)電路采用直徑為0.8 mm的漆包線自行繞制成圓形空心線圈天線，天線直徑為（3.4±0.3）cm。試驗(yàn)表明，探測(cè)節(jié)點(diǎn)與監(jiān)測(cè)終端的通信距離為24 cm，通過(guò)橋接方式，節(jié)點(diǎn)收發(fā)功率為102 mW時(shí)，節(jié)點(diǎn)間的通信距離可達(dá)20 cm。與傳統(tǒng)無(wú)線收發(fā)模塊相比，該無(wú)線收發(fā)電路在受體積、功耗、成本限制的場(chǎng)合有廣闊的應(yīng)用前景。
Abstract:
Based on ASK technology and with the C8051F340 and C8051F330D MCU as the controller， using half-duplex communication mode， this paper achieves bi-directional data transfer. Transceiver circuit constituted by enameled wire which diameter is 0.8mm and wound into a diameter （3.4±0.3） cm circular hollow coil antenna. Tests show that the communication distance between detection and monitoring of the terminal is 24cm，the distance is up to 20cm between two nodes when using the manner of bridging and the node transceiver power is 102mW. Compared with the conventional wireless transceiver modules， the circuit has wide application prospect in small size， low cost and low power consumption and other characteristics.
The Philips family of Multiplexers and Switches consists of bi-directional translating switches controlled via the I2C or SMBus to fan out an upstream SCL/SDA pair to 2, 4 or 8 downstream channels of SCx/SDx pairs. The Multiplexers allow only one downstream channel to be selected at a time, while the Switches allow any individual downstream channel or combination of downstream channels to be selected, depending on the content of the programmable control register. Once one or several channels have been selected, the device acts as a wire, allowing the master on the upstream channel to send commands to devices on all the active downstream channels, and devices on the active downstream channels to communicate with each other and the master. External pull-up resistors are used to pull each individual channel up to the desired voltage level. Combined interrupt output and hardware reset input are device options that are featured.
The MC68HC05K0 is a low cost, low pin countsingle chip microcomputer with 504 bytes of userROM and 32 bytes of RAM. The MC68HC05K0 isa member of the 68HC05K series of devices whichare available in 16-pin DIL or SOIC packages.It uses the same CPU as the other devices in the68HC05 family and has the same instructions andregisters. Additionally, the device has a 15-stagemulti-function timer and 10 general purposebi-directional I/0 lines. A mask option is availablefor software programmable pull-downs on all ofthe I/O pins and four of the pins are capable ofgenerating interrupts.The device is ideally suited for remote-controlkeyboard applications because the pull-downs andthe interrupt drivers on the port pins allowkeyboards to be built without any externalcomponents except the keys themselves. There isno need for external pull-up or pull-down resistors,or diodes for wired-OR interrupts, as these featuresare already designed into the device.
