product brief mc92314/MC92315 integrated ofdm demodulator for dvb-t implementation feature set usable for 8/7/6 mhz channels by adjusting the clock rate 2 k and 8 k transmission modes supported by the MC92315 (mc92314 is 2 k only) digital i/q separation on chip digital afc on chip supports qpsk, 16-qam and 64-qam (non-hierchical for the mc92314) supports all guard interval lengths (1/32, 1/16, 1/8, 1/4) automatic locking to any dvb-t guard interval accepts 8-bit ttl-compatible twos complement and offset-binary data input provides control signals for agc and adc clock frequency control dvb reed-solomon and viterbi decoders channel estimation and correction using the pilot carriers 3.3 v operation for the mc92314, 1.8 v for the MC92315 each part is pin compatible in a 160 qfp the mc92314 is a dvb-t (digital video broadcast-terrestrial) compliant demodulator for a 2 k transmission mode according to the etsi specification for digital terrestrial broadcasting. the MC92315 device is a pin-for-pin version of the mc92314 which supports the 8 k transmission mode as well. this two-part option allows for flexibility in cost for system designs without spending resources on engineering. both devices are derived from three 1st generation dtv parts: fft, ofdm demodulator and fec. the ofdm block combines an effective i/q demodulator with active, real time control blocks for afc and agc on the input. the fft block performs either a 2 k or 8 k (MC92315) length fourier transform and has a selectable output accuracy of 10 or 12-bit. the fec combines a dvb reed-solomon decoder, a viterbi decoder and error monitoring and bit-setting while allowing an output mpeg-2 transport stream rate of up to 37 mbit/s. mc92314/MC92315 block diagram motorola, inc. 1999 the mc92314/MC92315 has been designed with system effectiveness in mind. multi-path signals (which cause ghosting), signal strength conditions (which cause distortion to the picture) and many other artifacts need to be considered in a terrestrial design. the mc92314/MC92315 combines a high- performance, active front end along with a precise fft which allows the dvb-t system to operate normally under the worst conditions. operational interface is provided via a i 2 c bus protocol. operation is simplified by having the device preconfigured such that only minimal set up programmimg is required. motorola was the first to market the dvb-t demodulation technology and has provided its customers with a migration to more cost effective solutions. today, motorola provides a promising road-map, with state-of-the-art manufacturing capabilities, making them an attractive partner for the future.
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