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.
標(biāo)簽： bus bidirectional primarily designed
上傳時(shí)間： 2013-12-11
上傳用戶：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)
標(biāo)簽： implementation 729 Reference floating
上傳時(shí)間： 2017-04-10
上傳用戶：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.
標(biāo)簽： service packet available oriented
上傳時(shí)間： 2014-01-11
上傳用戶：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.
標(biāo)簽： service packet available oriented
上傳時(shí)間： 2013-12-20
上傳用戶：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.
標(biāo)簽： service packet available oriented
上傳時(shí)間： 2013-12-04
上傳用戶：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.
標(biāo)簽： frequency-domain interpolation performance Design Kbit_s speech coder based and of
上傳時(shí)間： 2018-04-08
上傳用戶：kilohorse
1引言由于環(huán)境溫度、濕度、油污等外界條件對諸如預(yù)付費(fèi)水表、預(yù)付費(fèi)燃?xì)獗怼㈩A(yù)付費(fèi)熱量表等接觸式卡表的影響明顯，卡座磨損、腐蝕，以及潮氣、灰塵等大大縮短了對卡表的使用壽命，因此非接觸卡表已成為當(dāng)前發(fā)展趨勢。這里給出了一種基于射頻器件MFRCS22"的智能儀表設(shè)計(jì)，提高了智能儀表的使命壽命。2 MFRC522簡介2.1 MFRC522的特點(diǎn)MFRC522采用串行通信方式與主機(jī)通信，可根據(jù)用戶需求，選用SPIPC或串行UART工作模式，有利于減少連線，縮小PCB板面積，降低成本。MFRC522主要特點(diǎn)如下：高度集成的調(diào)制解調(diào)電路，采用少量外部器件，即可將輸出驅(qū)動級接至天線；支持ISO/EC 14443 TypeA接口和MIFARE通信協(xié)議；支持多種主機(jī)接口：10 Mbitls的SPI接口；PC接口，快速模式的速率為400 Kbit/s，高速模式的速率為3400 Kbitls；串行UART，傳輸速率可以高達(dá)1 228.8 Kbits，取 RS232 口；特有的發(fā)送器掉電機(jī)制可關(guān)團(tuán)內(nèi)部天線驅(qū)動器，即關(guān)閉RF場，達(dá)到低功耗；內(nèi)置溫度傳感器，在過熱時(shí)自動停止RF發(fā)射；獨(dú)立的多組電源供電，避免相互干擾，優(yōu)化EMC特性和信號退構(gòu)性能；25 V-3.6 V的低壓、低功耗，采用5 mmx5mmx0.85 mm的超小型HVQFN32封裝。
上傳時(shí)間： 2022-06-20
上傳用戶：
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