an mpeg 2 decoder multichip module for digital tv and multimedia applications cyrus ghahremani, dr. arzu simsek, prof. herbert reichl fraunhofer institut fr zuverl?ssigkeit und mikrointegration gustav-meyer-allee 25 13355 berlin tel.: ++49 / 30 / 464 03 - 145 fax: ++49 / 30 / 464 03 - 111 email: ghahri@izm.fhg.de introduction the digitization of audiovisual and written information offers the possibility of joining them to one package and transmitting them via the same channel. now these different kinds of information can be processed on computers and any other common hardware. furthermore the user can interact with his system and manipulate the information instead of only consuming it. this conveniance means a high datarate to be transmitted and processed. so basing on the standard for teleconferencing h.261 and jpeg ( j oint p hotographic e xperts g roup) for images the m oving p ictures e xperts g roup ( mpeg ) established the standards mpeg 1 and mpeg 2. especially mpeg 2 addresses different kinds of applications which can be used in portable and stationary systems for computers or in consumer products. as portability and more functionality are the main selling features the systems have to be miniaturized. to meet these demands m ulti c hip m odules (mcm ) are a suitable means of designing systems of small size with high functionality. in this paper an mcm for mpeg 2 decoding is presented. possible applications in 1994 mpeg published the final version of mpeg 2 ?information technology - generic coding of moving pictures and associated audio information; international standard / recommendation iso / iec 13818?. this standard covers all aspects of digital coding and transmission of audiovisual information and supports for different applications such as dvb ( d igital v ideo b roadcast), dab ( d igital a udio b roadcast), dss ( d igital s atellite s ervices), dvd ( d igital v ersatile d isc) or videoconferencing. thus basing on the algorithms for data reduction described in the mpeg 2 standard subsystems for computers portable or stationary disc players codecs for handycams and for receivers for set-top-boxes and tv-sets can be designed. as the mpeg standards only describe the decoding algorithm and the bitstream organization parameters and features such as aspect ratio simulcasting audio formats and ca ( c onditional a ccess) have to be regarded individually for the particular application. in figure 1 the application areas for mpeg 2 decoder mcm are shown.
cpd98 2 mpeg-codec with dvd-support mpeg 2 codec mcm set-top-box with dvb and dss pcmcia-cards for notebooks pc plug-in cards (portable) dvd-player dvd-mcm figure 1: applications with an mpeg 2 decoder mcm mpeg 2 decoder mcm an mpeg 2 decoder mcm suitable for pc-cards or portable devices can consist of the decoder chip, the memory (figure 2) and if necessary a decryption engine for conditional access. memory 16 mbit mpeg 2 a/v decoder mpeg data in decompressed a/v data out mpeg 2 decoder mcm figure 2: mpeg 2 decoder mcm an area comparison between discrete smt devices and bare dice mounted on a substrate shows that the size shrinks to a quarter. so the whole decoder systems can be placed into a package as large as the package of the discrete mpeg decoder chip as shown in table 1 and figure 3.
cpd98 3 device quantity ic area / mm 2 die area / mm 2 mpeg decoder 1 900 129,96 dram 256k x 16 5 5 x 286 = 1430 5 x 27,15 = 135,75 total area 2330 265,71 table 1: area comparison packaged devices vs. bare dice mpeg 2 decoder ODM8211P micron dram 256k 16 micron dram 256k 16 micron dram 256k 16 micron dram 256k 16 micron dram 256k 16 mpeg 2 decoder ODM8211P dram dram dram dram dram pcb: 57,67 cm 2 mcm: 13,65 cm 2 space ratio: 4:1 7,3 cm. 7,9 cm. 3,5 cm. 3,9 cm. figure 3: size comparison packaged devices vs. bare dice if placed into a plcc package the mcm can be placed into a socket. then it can be removed and replaced by an upgraded version. this can also be achieved by mounting j- leads on the edges of the substrate. an alternative is putting bumps on the downside of the substrate and sealing the upside with a globtop. this is the most simple and cheapest way of getting a bga ( b all g rid a rray). this way no additional package is needed. this is suitable for small systems and applications in price sensitive market segments. conclusion with this technology various benefits can be gained. as the size is shrinked possible emc problems of the discrete smt solution caused by clock signals and high datarates can be minimized. the mcm offers a standardized interface. therefore silent upgrades can be made as the main changes occure in the mcm. a simple base system is suitable for many product generations. these properties of the mcm technology yield in design flexibility with shorter design time and lower development costs. furthermore one type of mcm can be used for a variety of products. the integration of further devices onto the mcm and combining it with other function units can yield in new product categories.
cpd98 4 references ?audio- und videodatenkompression mit mpeg2? prof. dr. r.r. grigat, tu hamburg harburg dipl.-ing. a. ibenthal, philips semiconductors/mk) funkschau 3/95 s. 26 ?der mpeg-2-standard? d. teichner fernseh- und kinotechnik 48. jahrgang nr. 4/1994 s. 155 dvd video dvd specifications for read-only disc toshiba, 1997 ?introduction to multichip modules? naveed sherwani, qiong yu, sandeep badida john wiley & sons, inc. new york/chichester/brisbane/toronto/singapore 1995
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