The Inter IC bus or I2C bus is a simple bidirectional two wire bus designed primarily for general control and data transfer communication between ICs. Some of the features of the I2C bus are: • Two signal lines, a serial data line (SDA) and a serial clock line (SCL), and ground are required. A 12V supply line (500mA max.) for powering the peripherals often may be present. • Each device connected to the bus is software addressable by a unique address and simple master/ slave relationships exist at all times masters can operate as master-transmitters or as master-receivers. • The I2C bus is a true multi-master bus including collision detection and arbitration to prevent data corruption if two or more masters simultaneously initiate data transfer systems. • Serial, 8-bit oriented, bidirectional data transfers can be made at up to 100 kbit/s in the standard mode or up to 400 kbit/s in the fast mode.
标签： bus bidirectional primarily designed
上传时间： 2013-12-10
上传用户：jeffery
ITU-T G.729 Annex C+ - Reference C code for floating point implementation of G.729 at 6.4/8/11.8 kbit/s with DTX functionality (integration of Annexes B, D and E)
标签： implementation 729 Reference floating
上传时间： 2017-04-10
上传用户：cccole0605
General packet radio service (GPRS) is a packet oriented mobile data service available to users of the 2G cellular communication systems global system for mobile communications (GSM), as well as in the 3G systems. In the 2G systems, GPRS provides data rates of 56-114 kbit/s.
标签： service packet available oriented
上传时间： 2014-01-11
上传用户：宋桃子
General packet radio service (GPRS) is a packet oriented mobile data service available to users of the 2G cellular communication systems global system for mobile communications (GSM), as well as in the 3G systems. In the 2G systems, GPRS provides data rates of 56-114 kbit/s.
标签： service packet available oriented
上传时间： 2013-12-19
上传用户：evil
General packet radio service (GPRS) is a packet oriented mobile data service available to users of the 2G cellular communication systems global system for mobile communications (GSM), as well as in the 3G systems. In the 2G systems, GPRS provides data rates of 56-114 kbit/s.
标签： service packet available oriented
上传时间： 2013-12-03
上传用户：894898248
The 4.0 kbit/s speech codec described in this paper is based on a Frequency Domain Interpolative (FDI) coding technique, which belongs to the class of prototype waveform Interpolation (PWI) coding techniques. The codec also has an integrated voice activity detector (VAD) and a noise reduction capability. The input signal is subjected to LPC analysis and the prediction residual is separated into a slowly evolving waveform (SEW) and a rapidly evolving waveform (REW) components. The SEW magnitude component is quantized using a hierarchical predictive vector quantization approach. The REW magnitude is quantized using a gain and a sub-band based shape. SEW and REW phases are derived at the decoder using a phase model, based on a transmitted measure of voice periodicity. The spectral (LSP) parameters are quantized using a combination of scalar and vector quantizers. The 4.0 kbits/s coder has an algorithmic delay of 60 ms and an estimated floating point complexity of 21.5 MIPS. The performance of this coder has been evaluated using in-house MOS tests under various conditions such as background noise. channel errors, self-tandem. and DTX mode of operation, and has been shown to be statistically equivalent to ITU-T (3.729 8 kbps codec across all conditions tested.
标签： frequency-domain interpolation performance Design kbit_s speech coder based and of
上传时间： 2018-04-08
上传用户：kilohorse
1引言由于环境温度、湿度、油污等外界条件对诸如预付费水表、预付费燃气表、预付费热量表等接触式卡表的影响明显，卡座磨损、腐蚀，以及潮气、灰尘等大大缩短了对卡表的使用寿命，因此非接触卡表已成为当前发展趋势。这里给出了一种基于射频器件MFRCS22"的智能仪表设计，提高了智能仪表的使命寿命。2 MFRC522简介2.1 MFRC522的特点MFRC522采用串行通信方式与主机通信，可根据用户需求，选用SPIPC或串行UART工作模式，有利于减少连线，缩小PCB板面积，降低成本。MFRC522主要特点如下：高度集成的调制解调电路，采用少量外部器件，即可将输出驱动级接至天线；支持ISO/EC 14443 TypeA接口和MIFARE通信协议；支持多种主机接口：10 Mbitls的SPI接口；PC接口，快速模式的速率为400 kbit/s，高速模式的速率为3400 kbitls；串行UART，传输速率可以高达1 228.8 kbits，取 RS232 口；特有的发送器掉电机制可关团内部天线驱动器，即关闭RF场，达到低功耗；内置温度传感器，在过热时自动停止RF发射；独立的多组电源供电，避免相互干扰，优化EMC特性和信号退构性能；25 V-3.6 V的低压、低功耗，采用5 mmx5mmx0.85 mm的超小型HVQFN32封装。
上传时间： 2022-06-20
上传用户：wky20090436
