ZL10354 Diversity Enabled Nordig Unified DVB-T COFDM Terrestrial Demodulator for PC-TV and Hand-held Digital TV (DTV) Data Sheet Features September 2005 • Compliant with ETSI 300 744 DVB-T, Unified Nordig and DTG performance specifications • Diversity enabled multi-tuner solution. • High performance with fast fully blind acquisition and tracking capability • Low power consumption: less than 0.32 W, and eco-friendly standby and sleep modes Ordering Information ZL10354QCG ZL10354QCG1 ZL10354QCF ZL10354QCF1 64 64 64 64 Pin Pin Pin Pin LQFP LQFP* LQFP LQFP* Trays, Trays, Trays, Trays, Bake Bake Bake Bake & & & & Drypack Drypack Drypack Drypack *Pb Free Matte Tin -40°C to +85°C • Single 8 MHz SAW filter for 6, 7 & 8 MHz OFDM • Superior single frequency network performance • Fast AGC to track out signal fades Applications • Advanced Doppler tracking capability • Digital terrestrial set-top boxes • Enhanced frequency capture range to include triple offsets • Integrated digital televisions • External 4 MHz clock or single low-cost 20.48 MHz crystal, tolerance up to +/-200 ppm • Personal video recorders • PC-TV receivers Portable applications • Automatic mode (2 K/8 K), guard and spectral inversion detection • • Very low driver software overhead due to on-chip state-machine control Description • Novel RF level detect facility via a separate ADC • Pre and post Viterbi-decoder bit error rates, and uncorrectable block count The ZL10354 is a superior fourth generation fully compliant ETSI ETS300 744 COFDM demodulator that exceeds, with margin, the performance requirements of all known DVB-T digital terrestrial television standards, including Unified Nordig and DTG. Figure 1 - Block Diagram 1 Zarlink Semiconductor Inc. Zarlink, ZL and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc. Copyright 2005, Zarlink Semiconductor Inc. All Rights Reserved. ZL10354 Data Sheet A high performance 10 bit on-chip ADC is used to sample the 44 or 36 MHz IF analog signal. Advanced digital filtering of the upper and lower channel enables a single 8 MHz channel SAW filter to be used for 6, 7 and 8 MHz OFDM signal reception. All sampling and other internal clocks are derived from a single 20.48 MHz crystal or a 4 MHz clock input, the tolerance of which may be relaxed as much as 200 ppm. The pinout of the ZL10354 is highly adaptable to allow multiple devices to be connected as a diversity receiver. Any number of ZL10354s can be connected together using the high-speed five-bit diversity data bus in a chain of devices. Together with separate aerials and tuners for each device, the combined performance of the connected demodulators will normally exceed a single device, especially in mobile applications or in areas where the signal is prone to echoes and/or fading. The ZL10354 has a wide frequency capture range able to automatically compensate for the combined offset introduced by the tuner xtal and broadcaster triple frequency offsets. An on-chip state machine controls all acquisition and tracking operations of the ZL10354 as well as controlling the tuner via a 2-wire bus. Any frequency range can be automatically scanned for digital TV channels. This mechanism ensures minimal interaction, maximum flexibility and fast acquisition - very low software overhead. Also included in the design is a 7-bit ADC to detect the RF signal strength and thereby efficiently control the tuner RF AGC. Users have access to all the relevant signal quality information, including input signal power level, signal-to-noise ratio, pre-Viterbi BER, post-Viterbi BER, and the uncorrectable block counts. The error rate monitoring periods are programmable over a wide range. The device is packaged in a 7 x 7 mm 64-pin LQFP and is very low power. 2 Zarlink Semiconductor Inc. ZL10354 Data Sheet Table of Contents 1.0 Pin & Package Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.1 Pin Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.2 Pin Allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.3 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.0 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.1 Analog-to-Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2 Automatic Gain Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 IF to Baseband Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.4 Adjacent Channel Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.5 Interpolation and Clock Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.6 Carrier Frequency Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.7 Symbol Timing Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.8 Fast Fourier Transform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.9 Common Phase Error Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.10 Channel Equalization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.11 Impulse Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.12 Transmission Parameter Signalling (TPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.13 Diversity Optimizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.14 De-Mapper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.15 Symbol and Bit De-Interleaving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.16 Viterbi Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.17 MPEG Frame Aligner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.18 De-interleaver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.19 Reed-Solomon Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.20 De-scrambler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.21 MPEG Transport Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.0 Diversity Operation of ZL10354 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.1 Pin Allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.0 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.1 2-Wire Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.1.1 Host . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.1.2 Tuner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.1.3 Examples of 2-Wire Bus Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.1.4 Primary 2-Wire Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.2 Diversity Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 4.3 MPEG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4.3.1 Data Output Header Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4.3.2 MPEG Data Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.3 MPEG Output Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.4 MOCLKINV = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4.3.5 MOCLKINV = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.0 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.1 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.2 Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.3 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5.4 Crystal Specification and External Clocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5.4.1 Selection of External Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 5.4.1.1 Loop Gain Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 5.4.1.2 List of Equation Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 5.4.1.3 Calculating Crystal Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 5.4.1.4 Capacitor Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 5.4.1.5 Oscillator/Clock Application Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3 Zarlink Semiconductor Inc. ZL10354 Data Sheet Table of Contents 6.0 Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4 Zarlink Semiconductor Inc. ZL10354 Data Sheet List of Figures Figure 1 - Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Figure 2 - Pin Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 3 - OFDM Demodulator Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 4 - FEC Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 5 - Outline Diversity System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 6 - Outline of Dual Diversity/Play-and-Record System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 7 - Basic Interconnections and Serial Address Options for Four ZL10354s on the Same Bus. . . . . . . . . . 20 Figure 8 - Primary 2-Wire Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 9 - Timing Diagram for the Diversity Bus with DvrClkInv = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 10 - DVB Transport Packet Header Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 11 - MPEG Output Data Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Figure 12 - MPEG Timing - MOCLKINV = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 13 - MPEG Timing - MOCLKINV = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 14 - Crystal Oscillator Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Figure 15 - External Clocking via AC Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Figure 16 - Typical Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 5 Zarlink Semiconductor Inc. ZL10354 Data Sheet List of Tables Table 1 - Pin Names - numeric. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 2 - Pin Names - alphabetical order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 3 - Pin Names Mode A - diversity first or last device in chain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 4 - Pin Names Mode B - diversity mid-chain device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 5 - Pin Names Mode C - non-diversity use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 6 - Diversity Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 7 - Timing of 2-Wire Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 8 - Diversity Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6 Zarlink Semiconductor Inc. ZL10354 1.0 Pin & Package Details 1.1 Pin Outline Data Sheet Figure 2 below shows the basic, non-diversity, pin functions of the ZL10354. The device can effectively be set up in seven different pin configurations, so for brevity only this version is shown. Figure 2 - Pin Outline 7 Zarlink Semiconductor Inc. ZL10354 1.2 Data Sheet Pin Allocation Pin Function Pin Function Pin Function Pin Function 1 Vss 17 SADD1 33 Vdd 49 MDO0/Dv0/ Dv1 2 Vdd 18 SADD0 34 RFLEV 50 MDO1/Dv1/ Dv3 3 Vss 19 CVdd 35 CLK2/GPP0 51 MDO2/Dv2 4 CLK1 20 Vss 36 DATA2/GPP1 52 MDO3/Dv3/ Dv1 5 DATA1 21 PLLVdd 37 CVdd 53 MDO4/Dv4/ Dv0 6 IRQ/Dv4/Dv0 22 PLLGND 38 Vss 54 Vdd 7 CVdd 23 XTI 39 CVdd 55 Vss 8 Vss 24 XTO 40 Vss 56 MDO5 9 RESET 25 Vss 41 AGC2/GPP2/DvVal 57 MDO6 10 SLEEP 26 PLLTEST 42 AGC1 58 MDO7 11 STATUS/Dv3/ Dv1 27 OSCMODE 43 GPP3/DvClk 59 CVdd 12 N/C 28 AVdd 44 SMTEST 60 Vss 13 Vdd 29 AGnd 45 Vdd 61 MOCLK/DvClk 14 Vss 30 VIN 46 Vss 62 BKERR 15 N/C 31 VIN 47 MOSTRT 63 MICLK 16 N/C 32 AGnd 48 MOVAL/DvVal 64 CVdd Table 1 - Pin Names - numeric Function Pin Function Pin Function Pin Function Pin AGC1 42 GPP3/DvClk 43 PLLTEST 26 Vdd 54 AGC2/GPP2/DvVal 41 IRQ/Dv4/Dv0 6 PLLVdd 21 VIN 30 AGnd 29 MDO0/Dv0/ Dv1 49 RESET 9 VIN 31 AGnd 32 MDO1/Dv1/ Dv3 50 RFLEV 34 Vss 1 AVdd 28 MDO2/Dv2 51 SADD0 18 Vss 3 BKERR 62 MDO3/Dv3/ Dv1 52 SADD1 17 Vss 8 CLK1 4 MDO4/Dv4/ Dv0 53 N/C/Dv0/Dv1 16 Vss 14 CLK2/GPP0 35 MDO5 56 N/C/Dv1/Dv3 15 Vss 20 CVdd 7 MDO6 57 N/C/Dv2 12 Vss 25 CVdd 19 MDO7 58 SLEEP 10 Vss 38 Table 2 - Pin Names - alphabetical order 8 Zarlink Semiconductor Inc. ZL10354 Data Sheet CVdd 37 MICLK 63 SMTEST 44 Vss 40 CVdd 39 MOCLK/DvClk 61 STATUS/Dv3/ Dv1 11 Vss 46 CVdd 59 MOSTRT 47 Vdd 2 Vss 55 CVdd 64 MOVAL/DvVal 48 Vdd 13 Vss 60 DATA1 5 OSCMODE 27 Vdd 33 XTI 23 DATA2/GPP1 36 PLLGND 22 Vdd 45 XTO 24 Table 2 - Pin Names - alphabetical order (continued) 1.3 Pin Description Pin Description Table Pin No Name Pin Description I/O Type V mA MPEG pins 47 MOSTRT MPEG packet start O 3.3 1 48 MOVAL (or DvVal-O) MPEG/diversity data valid O 3.3 1 49-53, 56-58 MDO(0:4)/Dv(0:4)-O MDO(5:7) MPEG/diversity data bus O 3.3 1 61 MOCLK (or DvClk-O) MPEG/diversity clock out O 3.3 1 62 BKERR Block error O 3.3 1 63 MICLK MPEG clock in I 11 STATUS (or Dv3/1) Status output or diversity data I/O 6 IRQ (or Dv4/0) Interrupt output or diversity data I/O 4 CLK1 Serial clock 5 DATA1 23 XTI 24 XTO 10 SLEEP CMOS Tristate 3.3 CMOS 3.3 1 Open drain 5 6 I CMOS 5 Serial data I/O Open drain 5 Low phase noise oscillator I Control pins N/C O Device power down I 3.3 I/O 3.3 Dv2,1,0/2,3,4 N/C or Diversity data I/O 3.3 17, 18 SADD(1:0) Serial address set I 3.3 44 SMTEST Production test (only set low) I 3.3 12, 15, 16 9 Zarlink Semiconductor Inc. CMOS 6 ZL10354 Data Sheet Pin Description Table (continued) Pin No Name Pin Description I/O Type V mA 35 CLK2/GPP0 Serial clock tuner I/O 5 6 36 DATA2/GPP1 Serial data tuner I/O 5 6 42 AGC1 Primary AGC O 5 6 41 AGC2/GPP2 Secondary AGC I/O 5 6 43 GPP(3) General purpose I/O I/O 5 6 9 RESET Device reset I CMOS 5 27 OSCMODE Crystal oscillator mode I CMOS 3.3 26 PLLTEST PLL analog test O (tristated) 30 VIN positive input I 31 VIN negative input I 34 RFLEV RF level I 21 PLLVdd PLL supply S 1.8 22 PLLGnd S 0 7, 19, 37, 39, 59, 64 CVdd Core logic power S 1.8 2, 13, 45, 54, Vdd I/O ring power S 3.3 1, 3, 8, 14, 20, 25, 38, 40, 46, 55, 60 Vss Core and I/O ground S 0 28 AVdd ADC analog supply S 1.8 29, 32 AGnd S 0 33 Vdd S 3.3 Open drain Analog inputs Supply pins 2nd ADC supply 10 Zarlink Semiconductor Inc. ZL10354 2.0 Data Sheet Functional Description A functional block diagram of the ZL10354 OFDM demodulator is shown in Figure 3. This accepts an IF analog signal and delivers a stream of demodulated soft decision data to the on-chip Viterbi decoder. Clock, timing and frequency synchronization operations are all digital and there are no analog control loops except the AGC. The frequency capture range is large enough for all practical applications. This demodulator has novel algorithms to combat impulse noise as well as co-channel and adjacent channel interference. If the modulation is hierarchical, the OFDM outputs both high and low priority data streams. Only one of these streams is FEC-decoded, but the FEC can be switched from one stream to another with minimal interruption to the transport stream. Figure 3 - OFDM Demodulator Diagram The FEC module shown in Figure 4 consists of a concatenated convolutional (Viterbi) and Reed-Solomon decoder separated by a depth-12 convolutional de-interleaver. The Viterbi decoder operates on 5-bit soft decisions to provide the best performance over a wide range of channel conditions. The trace-back depth of 128 ensures minimum loss of performance due to inevitable survivor truncation, especially at high code rates. Both the Viterbi and Reed-Solomon decoders are equipped with bit-error monitors. The former provides the bit error rate (BER) at the OFDM output. The latter is the more useful measure as it gives the Viterbi output BER. The error collecting intervals of these are programmable over a very wide range. 11 Zarlink Semiconductor Inc. ZL10354 Data Sheet Figure 4 - FEC Block Diagram The FSM controller shown in Figure 3 controls both the demodulator and the FEC. It also drives the 2-wire bus to the tuner. The controller facilitates the automated search of all parameters or any sub-set of parameters of the received signal. It can also be used to scan any defined frequency range searching for OFDM channels. This mechanism provides the fast channel scan and acquisition performance, whilst requiring minimal software overhead in the host driver. The algorithms and architectures used in the ZL10354 have been optimized to minimize power consumption. 2.1 Analog-to-Digital Converter The ZL10354 has a high performance 10-bit analog-to-digital converter (ADC) which can sample a 6, 7 or 8 MHz bandwidth OFDM signal, with its spectrum centred at: • 36.17 MHz IF • 43.75 MHz IF • 5 - 10 MHz near-zero IF An on-chip programmable phase locked loop (PLL) is used to generate the ADC sampling clock. The PLL is highly programmable allowing a wide choice of sampling frequencies to suit any IF frequency, and all signal bandwidths. 2.2 Automatic Gain Control An AGC module compares the absolute value of the digitized signal with a programmable reference. The error signal is filtered and is used to control the gain of the amplifier. A sigma-delta modulated output is provided, which has to be RC low-pass filtered to obtain the voltage to control the amplifier. The programmable AGC reference has been optimized. A large value for the reference leads to excessive ADC clipping and a small value results in excessive quantization noise. Hence the optimum value has been determined assuming the input signal amplitude to be Gaussian distributed. The latter is justified by applying the central limit theorem in statistics to the OFDM signal, which consists of a large number of randomly modulated carriers. This reference or target value may have to be lowered slightly for some applications. Slope control bits have been provided for the AGCs and these have to be set correctly depending on the gain-versus-voltage slope of the gain control amplifiers. 12 Zarlink Semiconductor Inc. ZL10354 Data Sheet The bandwidth of the AGC is set to a large value for quick acquisition then reduced to a small value for tracking. The AGC is free running during OFDM channel changes and locks to the new channel while the tuner lock is being established. This is one of the features of ZL10354 used to minimize acquisition time. A robust AGC lock mechanism is provided and the other parts of the ZL10354 begin to acquire only after the AGC has locked. 2.3 IF to Baseband Conversion Sampling a 36.17 MHz IF signal at 45 MHz results in a spectrally inverted OFDM signal centred at approximately 8.9 MHz. The first step of the demodulation process is to convert this signal to a complex (in-phase and quadrature) signal in baseband. A correction for spectral inversion is implemented during this conversion process. Note also that the ZL10354 has control mechanisms to search automatically for an unknown spectral inversion status. 2.4 Adjacent Channel Filtering Adjacent channels, in particular the Nicam digital sound signal associated with analog channels, are filtered prior to the FFT. 2.5 Interpolation and Clock Synchronization ZL10354 uses digital timing recovery and this eliminates the need for an external VCXO. The ADC samples the signal at a fixed rate, for example, 45.056 MHz. Conversion of the 45.056 MHz signal to the OFDM sample rate is achieved using the time-varying interpolator. The OFDM sample rate is 64/7 MHz for 8 MHz and this is scaled by factors 6/8 and 7/8 for 6 and 7 MHz channel bandwidths. The nominal ratio of the ADC to OFDM sample rate is programmed in a ZL10354 register (defaults are for 45 MHz sampling and 8 MHz OFDM). The clock recovery phase locked loop in the ZL10354 compensates for inaccuracies in this ratio due to uncertainties of the frequency of the sampling clock. 2.6 Carrier Frequency Synchronization There can be frequency offsets in the signal at the input to OFDM, partly due to tuner step size and partly due to broadcast frequency shifts, typically 1/6 MHz. These are tracked out digitally, up to 1 MHz in 2 K and 8 K modes, without the need for an analog frequency control (AFC) loop. The default frequency capture range has been set to ±286 kHz in the 2 K and 8 K mode. However, these values can be increased, if necessary, by programming an on-chip register (see 7.4.1). It is recommended that a larger capture range be used for channel scan in order to find channels with broadcast frequency shifts, without having to adjust the tuner. After the OFDM module has locked (the AFC will have been previously disabled), the frequency offset can be read from an on-chip register. 2.7 Symbol Timing Synchronization This module computes the optimum sample position to trigger the FFT in order to eliminate or minimize inter-symbol interference in the presence of multi-path distortion. Furthermore, this trigger point is continuously updated to dynamically adapt to time-variations in the transmission channel. 2.8 Fast Fourier Transform The FFT module uses the trigger information from the timing synchronization module to set the start point for an FFT. It then uses either a 2 K or 8 K FFT to transform the data from the time domain to the frequency domain. An extremely hardware-efficient and highly accurate algorithm has been used for this purpose. 13 Zarlink Semiconductor Inc. ZL10354 2.9 Data Sheet Common Phase Error Correction This module subtracts the common phase offset from all the carriers of the OFDM signal to minimize the effect of the tuner phase noise on system performance. 2.10 Channel Equalization This consists of two parts. The first part involves estimating the channel frequency response from pilot information. Efficient algorithms have been used to track time-varying channels with a minimum of hardware. The second part involves applying a correction to the data carriers based on the estimated frequency response of the channel. This module also generates dynamic channel state information (CSI) for every carrier in every symbol. 2.11 Impulse Filtering ZL10354 contains several mechanisms to reduce the impact of impulse noise on system performance. 2.12 Transmission Parameter Signalling (TPS) An OFDM frame consists of 68 symbols and a superframe is made up of four such frames. There is a set of TPS carriers in every symbol and all these carry one bit of TPS. These bits, when combined, include information about the transmission mode, guard ratio, constellation, hierarchy and code rate, as defined in ETS 300 744. In addition, the first eight bits of the cell identifier are contained in even frames and the second eight bits of the cell identifier are in odd frames. The TPS module extracts all the TPS data, and presents these to the host processor in a structured manner. 2.13 Diversity Optimizer When two or more ZL10354s are combined in a chain using their diversity buses, the first stage chip operates in the normal way on a single tuner source, however the channel-corrected OFDM data are output to the next device in the chain. This ZL10354 combines the received diversity data with the channel-corrected data from its own OFDM demodulation process, selecting the optimum data from each source for any given carrier. The resulting data are either passed to another ZL10354 for further combining, or the FEC logic to generate an MPEG transport stream. 2.14 De-Mapper This module generates soft decisions for demodulated bits using the channel-equalized in-phase and quadrature components of the data carriers as well as per-carrier channel state information (CSI). The de-mapping algorithm depends on the constellation (QPSK, 16QAM or 64QAM) and the hierarchy (α = 0, 1, 2 or 4). Soft decisions for both low- and high-priority data streams are generated. 2.15 Symbol and Bit De-Interleaving The OFDM transmitter interleaves the bits within each carrier and also the carriers within each symbol. The de-interleaver modules consist largely of memory to invert these interleaving functions and present the soft decisions to the FEC in the original order. 14 Zarlink Semiconductor Inc. ZL10354 2.16 Data Sheet Viterbi Decoder The Viterbi decoder accepts the soft decision data from the OFDM demodulator and outputs a decoded bit-stream. The decoder does the de-puncturing of the input data for all code rates other than 1/2. It then evaluates the branch metrics and passes these to a 64-state path-metric updating unit, which in turn outputs a 64-bit word to the survivor memory. The Viterbi decoded bits are obtained by tracing back the survivor paths in this memory. A trace-back depth of 128 is used to minimize any loss in performance, especially at high code rates. The decoder re-encodes the decoded bits and compares these with received data (delayed) to compute bit errors at its input, on the assumption that the Viterbi output BER is significantly lower than its input BER. 2.17 MPEG Frame Aligner The Viterbi decoded bit stream is aligned into 204-byte frames. A robust synchronization algorithm is used to ensure correct lock and to prevent loss of lock due to noise impulses. 2.18 De-interleaver Errors at the Viterbi output occur in bursts and the function of the de-interleaver is to spread these errors over a number of 204-byte frames to give the Reed-Solomon decoder a better chance of correcting these. The de-interleaver is a memory unit which implements the inverse of the convolutional interleaving function introduced by the transmitter. 2.19 Reed-Solomon Decoder Every 188-byte transport packet is encoded by the transmitter into a 204-byte frame, using a truncated version of a systematic (255,239) Reed-Solomon code. The corresponding (204,188) Reed-Solomon decoder is capable of correcting up to eight byte errors in a 204-byte frame. It may also detect frames with more than eight byte errors. In addition to efficiently performing this decoding function, the Reed-Solomon decoder in ZL10354 keeps a count of the number of bit errors corrected over a programmable period and the number of uncorrectable blocks. This information can be used to compute the post-Viterbi BER. 2.20 De-scrambler The de-scrambler de-randomizes the Reed-Solomon decoded data by generating the exclusive-OR of this with a pseudo-random bit sequence (PRBS). This outputs 188-byte MPEG transport packets. The TEI bit of the packet header may be set if required to indicate uncorrectable packets. 2.21 MPEG Transport Interface MPEG data can be output in parallel or serial mode. The output clock frequency is automatically chosen to present the MPEG data as uniformly spaced as possible to the transport processor. This frequency depends on the guard ratio, constellation, hierarchy and code rate. There is also an option for the data to be extracted from the ZL10354 with a clock provided by the user. 15 Zarlink Semiconductor Inc. ZL10354 3.0 Data Sheet Diversity Operation of ZL10354 The ZL10354 demodulator can be used as a stand-alone system, but is designed primarily for use as part of a multi-receiver system in which two or more tuners, each with their own aerial, are connected to the same number of ZL10354s. This is shown in general form in Figure 5. Figure 5 - Outline Diversity System The ZL10354s are connected together in a chain using the diversity data bus, a high-speed, 5-bit bus which feeds channel-corrected, ODFM data to the next demodulator in the chain. Each subsequent ZL10354 combines the incoming OFDM data with its own received data to get the optimum reception for each carrier. The SADD1 and SADD0 pins allow up to four ZL10354s to each be defined with a different serial bus address, but the system is not limited to four devices. However, each group of (up to) four ZL10354s must be controlled via a separate serial bus to avoid address clashes. The other main requirement is that all the demodulators are driven from the same clock source. The diversity data are transferred from one device to the next through either the diversity pins, or parts of the MPEG bus, which isn’t (usually) required on any device other than the last. The diversity bus pins are very flexible, being definable as either inputs or outputs, and when defined as inputs, the data pin order can be swapped. This flexibility eases the PCB layout issues considerably. In effect, six different pinouts can be defined for the ZL10354, in addition to the default non-diversity pinout. These pinout possibilities are shown in detail in Table 6, the non-diversity pin list is in Table 5, and the two main diversity pin list options are in Table 3 and Table 4. In these latter two tables the bus pin swap options are not shown. The versatility of this approach can be demonstrated with a dual receiver system (see Figure 6) in which the two ZL10354 based receivers can function either as a single diversity receiver, giving improved reception in mobile environments, or as a dual non-diversity receiver where two MPEG streams from different channels are required for picture-in-picture or play-and-record applications. 16 Zarlink Semiconductor Inc. ZL10354 Data Sheet Figure 6 - Outline of Dual Diversity/Play-and-Record System Although the two functions are very different, this one hardware design can easily be used in either mode just by setting the appropriate diversity register bits, and of course using appropriate software for tuning the same channel on both receivers, or two different channels. 3.1 Pin Allocation Pin Function Pin Function Pin 1 Vss 17 SADD1 33 2 Vdd 18 SADD0 3 Vss 19 4 CLK1 5 DATA1 Function Pin Function Vdd 49 MDO0 34 RFLEV 50 MDO1 CVdd 35 CLK2/GPP0 51 MDO2 20 Vss 36 DATA2/GPP1 52 MDO3 21 PLLVdd 37 CVdd 53 MDO4 6 Dv4 1 22 PLLGND 38 Vss 54 Vdd 7 CVdd 23 XTI 39 CVdd 55 Vss 8 Vss 24 XTO 40 Vss 56 MDO5 57 MDO6 58 MDO7 59 CVdd 9 RESET 25 Vss 41 DvVal 10 SLEEP 26 PLLTEST 42 AGC1 3 Dv3 2 27 OSCMODE 43 DvClk 12 Dv2 3 28 AVdd 44 SMTEST 60 Vss 13 Vdd 29 AGnd 45 Vdd 61 MOCLK 14 Vss 30 VIN 46 Vss 62 BKERR 11 3 Table 3 - Pin Names Mode A - diversity first or last device in chain 17 Zarlink Semiconductor Inc. ZL10354 Pin Function Pin Function Pin 15 Dv1 4 31 VIN 47 16 Dv0 5 32 AGnd 48 Function Data Sheet Pin Function MOSTRT 63 MICLK MOVAL 64 CVdd Table 3 - Pin Names Mode A - diversity first or last device in chain (continued) 1. Can be defined as either an input or output and can be swapped with Dv0 when used as an input. 2. Can be defined as either an input or output and can be swapped with Dv1 when used as an input. 3. Can be defined as either an input or output. 4. Can be defined as either an input or output and can be swapped with Dv3 when used as an input. 5. Can be defined as either an input or output and can be swapped with Dv4 when used as an input. Pin Function Pin Pin Function 1 Vss 17 SADD1 33 Vdd 49 Dv0-O 2 Vdd 18 SADD0 34 RFLEV 50 Dv1-O 3 Vss 19 CVdd 35 CLK2/GPP0 51 Dv2-O 4 CLK1 20 Vss 36 DATA2/GPP1 52 Dv3-O 5 DATA1 21 PLLVdd 37 CVdd 53 Dv4-O 1 6 Dv4-I 22 PLLGND 38 Vss 54 Vdd 7 CVdd 23 XTI 39 CVdd 55 Vss 8 Vss 24 XTO 40 Vss 56 MDO5 4 9 RESET 25 Vss 41 DvVal-I 57 MDO6 4 10 SLEEP 26 PLLTEST 42 AGC1 58 MDO7 4 11 Dv3-I 2 27 OSCMODE 43 DvClk-I 59 CVdd 12 Dv2-I 28 AVdd 44 SMTEST 60 Vss 13 Vdd 29 AGnd 45 Vdd 61 DvClk-O 14 Vss 30 VIN 46 Vss 62 BKERR 15 Dv1-I 3 31 VIN 47 MOSTRT 4 63 MICLK 16 5 32 AGnd 48 DvVal-O 64 CVdd Dv0-I Function Pin Function Table 4 - Pin Names Mode B - diversity mid-chain device 1. Can be swapped with Dv0-I 2. Can be swapped with Dv1-I 3. Can be swapped with Dv3-I 4. Held low in this mode 5. Can be swapped with Dv4-I Pin Function Pin Function Pin 1 Vss 17 SADD1 33 2 Vdd 18 SADD0 3 Vss 19 4 CLK1 5 DATA1 Function Pin Function Vdd 49 MDO0 34 RFLEV 50 MDO1 CVdd 35 CLK2/GPP0 51 MDO2 20 Vss 36 DATA2/GPP1 52 MDO3 21 PLLVdd 37 CVdd 53 MDO4 Table 5 - Pin Names Mode C - non-diversity use 18 Zarlink Semiconductor Inc. ZL10354 Pin Function Pin Function Pin 6 IRQ 22 PLLGND 38 7 CVdd 23 XTI 8 Vss 24 9 RESET 10 Function Data Sheet Pin Function Vss 54 Vdd 39 CVdd 55 Vss XTO 40 Vss 56 MDO5 25 Vss 41 AGC2/GPP2 57 MDO6 SLEEP 26 PLLTEST 42 AGC1 58 MDO7 11 STATUS 27 OSCMODE 43 GPP3 59 CVdd 12 N/C 28 AVdd 44 SMTEST 60 Vss 13 Vdd 29 AGnd 45 Vdd 61 MOCLK 14 Vss 30 VIN 46 Vss 62 BKERR 15 N/C 31 VIN 47 MOSTRT 63 MICLK 16 N/C 32 AGnd 48 MOVAL 64 CVdd Table 5 - Pin Names Mode C - non-diversity use (continued) In Table 6 all the possible variations are shown, of which pin numbers on the ZL10354 can be used for each of the diversity bus functions. This versatility - six different diversity pinout options - eases board layout constraints and allows the high speed diversity data buses between devices to be kept as short as possible. PortEn DvrInEn DvrSwp Out In Out In Out In Out In Out In Out In Out In 0 1 0 X 16 - 15 - 12 - 11 - 6 - 43 - 41 - 0 X 1 1 0 - 16 - 15 - 12 - 11 - 6 - 43 - 41 0 X 1 1 1 - 6 - 11 - 12 - 15 - 16 - 43 - 41 Table 3 2,4 1 1 0 0 X 49 - 50 - 51 - 52 - 53 - 61 - 48 - Table 4 1,3 1 1 1 1 0 49 16 50 15 51 12 52 11 53 6 61 43 48 41 1 1 1 1 1 49 6 50 11 51 12 52 15 53 16 61 43 48 41 0 X 0 0 X - - - - - - - - - - - - - - Dv1 Dv2 Dv3 Dv4 DvClk Table 6 - Diversity Pin Configurations 1. Option for the first device in a diversity chain. 2. Option for the last device in a diversity chain. 3. Diversity input pins can be used for their non-diversity functions as in Table 5. 4. Dv0 to Dv4 inputs are reversed relative to the names given in Table 3/Table 4. 19 Zarlink Semiconductor Inc. DvVal Pinout DvrPort 1 Dv0 Mode DvrOpEn Control of the diversity hardware functions is through six bits, three in the CONFIG register (address 0x50, see page 56) and three in the DVR_CTL register (address 0x59, see page 56). The function of these bits is described in detail in the relevant register descriptions, which should be read in conjunction with reference to Table 6. Table 3 1 A B Table 3 2 Table 4 Table 4 4 C Table 5 Figure 7 - Basic Interconnections and Serial Address Options for Four ZL10354s on the Same Bus ZL10354 4.0 Interfaces 4.1 2-Wire Bus 4.1.1 Data Sheet Host The primary 2-wire bus serial interface uses pins: • DATA1 (pin 5) serial data, the most significant bit is sent first. • CLK1 (pin 4) serial clock. The 2-wire bus address is determined by applying VDD or VSS to the SADD[4:0] pins. In TNIM evaluation applications, the 2-wire bus address is 0001 111 R/W with the pins connected as follows: ADDR[7] ADDR[6] ADDR[5] ADDR[4] ADDR[3] Not programmable VSS VSS VSS VDD VDD ADDR[2] ADDR[1] SADD[1] SADD[0] VDD VDD When the ZL10354 is powered up, the RESET pin 9 should be held low for at least 50 ms after VDD has reached normal operation levels. As the RESET pin goes high, the logic levels on SADD[4:0] are latched as the 2-wire bus address. ADDR[0] is the R/W bit. The circuit works as a slave transmitter with the lsb set high or as a slave receiver with the lsb set low. In receive mode, the first data byte is written to the RADD virtual register, which forms the register sub-address. The RADD register takes an 8-bit value that determines which of 256 possible register addresses is written to by the following byte. Not all addresses are valid and many are reserved registers that must not be changed from their default values. Multiple byte reads or writes will auto-increment the value in RADD, but care should be taken not to access the reserved registers accidentally. Following a valid chip address, the 2-wire bus STOP command resets the RADD register to 00. If the chip address is not recognized, the ZL10354 will ignore all activity until a valid chip address is received. The 2-wire bus START command does NOT reset the RADD register to 00. This allows a combined 2-wire bus message, to point to a particular read register with a write command, followed immediately with a read data command. If required, this could next be followed with a write command to continue from the latest address. RADD would not be sent in this case. Finally, a STOP command should be sent to free the bus. When the 2-wire bus is addressed (after a recognized STOP command) with the read bit set, the first byte read out is the contents of register 00. 4.1.2 Tuner The ZL10354 has a General Purpose Port that can be configured to provide a secondary 2-wire bus. See register GPP_CTL address 0x8C. Master control mode is selected by setting register SCAN_CTL (0x62) [b3] = 1. The allocation of the pins is: GPP0 pin 35 = CLK2, GPP1 pin 36 = DATA2. 21 Zarlink Semiconductor Inc. ZL10354 4.1.3 Data Sheet Examples of 2-Wire Bus Messages KEY: S Start condition W Write (= 0) P Stop condition R Read (= 1) A Acknowledge NA NOT Acknowledge Italics ZL10354 output RADD Register Address Write operation - as a slave receiver: S DEVICE W A RADD ADDRESS A DATA (n) A (reg n) DATA A P (reg n+1) Read operation - ZL10354 as a slave transmitter: S DEVICE R A ADDRESS DATA A DATA (reg 0) A (reg 1) DATA NA P (reg 2) Write/read operation with repeated start - ZL10354 as a slave transmitter: S DEVICE W A RADD ADDRESS 4.1.4 A S (n) DEVICE R A DATA ADDRESS A (reg n) DATA NA (reg n+1) Primary 2-Wire Bus Timing t BUFF Sr P DATA1 t LOW tR tF CLK1 P S t HD;STA t HD;DAT t HIGH t SU;DAT t SU;STA Figure 8 - Primary 2-Wire Bus Timing Where: P S = Start Sr = Restart, i.e., start without stopping first. P = Stop. 22 Zarlink Semiconductor Inc. t SU;STO ZL10354 Data Sheet Value Parameter Symbol Unit Min. Max. 400 1 CLK clock frequency (Primary) fCLK 0 Bus free time between a STOP and START condition. tBUFF 200 ns Hold time (repeated) START condition. tHD;STA 200 ns LOW period of CLK clock. tLOW 1300 ns HIGH period of CLK clock. tHIGH 600 ns Set-up time for a repeated START condition. tSU;STA 200 ns Data hold time (when input). tHD;DAT 100 ns Data set-up time tSU;DAT 100 ns Rise time of both CLK and DATA signals. tR Fall time of both CLK and DATA signals, (100 pF to ground). tF 20 ns Set-up time for a STOP condition. tSU;STO 200 ns note 2 kHz ns Table 7 - Timing of 2-Wire Bus 1. If operating with an external 4 MHz clock, the serial clock frequency is reduced to 100 kHz maximum. 2. The rise time depends on the external bus pull up resistor. Loading prevents full speed operation. 4.2 Diversity Bus The diversity bus is a high speed 5-bit data bus that allows OFDM data from multiple ZL10354s to be optimized on a carrier by carrier basis. The diversity clock is output at the ADC clock rate and in the receiving device latches the data and validation bit on the rising edge. To achieve this with the optimum timing parameters, the clock should be inverted by setting the DvrClkInv bit in the DVR_CTL register (address 0x59) as part of the setup routine when using a diversity system. Figure 9 - Timing Diagram for the Diversity Bus with DvrClkInv = 1 23 Zarlink Semiconductor Inc. ZL10354 Data Sheet Timing conditions Parameter Diversity clock period tDvrP Units Minimum Maximum 22.06 28.48 Diversity setup time tDvrSU tba Diversity hold time tDvrH tba ns Table 8 - Diversity Bus Timing 4.3 4.3.1 MPEG Data Output Header Format 188 byte packet output 184 Transport packet bytes Transport Packet Header 4 bytes 0 1 0 0 0 1 1 1 1st byte 2nd byte TEI MDO[7] MDO[0] Figure 10 - DVB Transport Packet Header Byte After decoding the 188-byte MPEG packet, it is output on the MDO pins in 188 consecutive clock cycles. Additionally when the TEI_En bit in the OP_CTRL_0 register (0x5A) is set high (default), the TEI bit of any uncorrectable packet will automatically be set to ‘1’. If TEI_En bit is low then TEI bit will not be changed (but note that if this bit is already 1, for example, due to a channel error which has not been corrected, it will remain high at output). 24 Zarlink Semiconductor Inc. ZL10354 4.3.2 Data Sheet MPEG Data Output Signals The MPEGEN bit in the CONFIG register must be set low to enable the MPEG data. The maximum movement in the packet synchronization byte position is limited to ±1 output clock period. MOCLK will be a continuously running clock once symbol lock has been achieved, and is derived from the symbol clock. MOCLK is shown in Figure 11 with MOCLKINV = ‘1’, the default state, see register 0x50. All output data and signals (MDO[7:0], MOSTRT, MOVAL & BKERR) change on the negative edge of MOCLK (MOCLKINV = 1) to present stable data and signals on the positive edge of the clock. A complete packet is output on MDO[7:0] on 188 consecutive clocks and the MDO[7:0] pins will remain low during the inter-packet gaps. MOSTRT goes high for the first byte clock of a packet. MOVAL goes high on the first byte of a packet and remains high until the last byte has been clocked out. BKERR goes low on the first byte of a packet where uncorrectable bytes are detected and will remain low until the last byte has been clocked out. 188 byte packet n 1st byte packet n 1st byte packet n+1 MOCLKINV=1 MOCLK MDO7:0 MOSTRT MOVAL BKERR Tp Ti Figure 11 - MPEG Output Data Waveforms 4.3.3 MPEG Output Timing Maximum delay conditions: VDD = 3.0V, CVDD = 1.62V, Tamb = 85oC, Output load = 10pF. Minimum delay conditions: VDD = 3.6V, CVDD = 1.98V, Tamb = -40oC, Output load = 10pF. MOCLK frequency = 45.06 MHz. 25 Zarlink Semiconductor Inc. ZL10354 4.3.4 Data Sheet MOCLKINV = 1 Delay conditions Parameter Units Maximum Minimum Data output delay tD 3.0 1.0 Setup Time tSU 7.0 10.0 Hold Time tH 7.0 10.0 ns MOCLK MDO MOSTRT MOVAL BKERRB BKERR tD } tSU tH Figure 12 - MPEG Timing - MOCLKINV = 1 4.3.5 MOCLKINV = 0 MDOSWAP = 0 Delay conditions Parameter Units Maximum Minimum 3.0 1.0 18.0 20.0 1.0 0.2 Data output delay tD Setup Time tSU Hold Time tH ns The hold time is better when MOCLKINV = 1, therefore this should be used if possible. MOCLK MDO MOSTRT MOVAL BKERRB BKERR } tD tSU tH Figure 13 - MPEG Timing - MOCLKINV = 0 26 Zarlink Semiconductor Inc. ZL10354 5.0 Electrical Characteristics 5.1 Recommended Operating Conditions Parameter Power supply voltage: Power supply current: Data Sheet Symbol Min. Typ. Max. Units VDD 3.0 3.3 3.6 V core CVDD 1.62 1.8 1.98 V periphery 1 IDDP 1 mA core IDDC 170 mA 2 periphery Input clock frequency 3 XTI CLK1 primary serial clock frequency 4 16.00 20.48 fCLK Ambient operating temperature -40 25.00 MHz 400 kHz 85 °C 1. Current from the 3.3 V supply will be mainly dependent on the external loads. 2. Current given is for optimum performance, lower current is possible with reduced performance. 3. The min/max frequencies given are those supported by the oscillator cell. Required system frequencies are as defined in the design manual. Frequencies outside these limits are acceptable with an external clock signal. 4. If operating with an external 4 MHz clock, the serial clock frequency is reduced to 100 kHz maximum. 5.2 Absolute Maximum Ratings Maximum Operating Conditions Parameter Symbol Min. Max. Unit VDD -0.3 +3.6 V CVDD -0.3 +2.0 V Voltage on input pins (5 V rated) VI -0.3 5.5 V Voltage on input pins (3.3 V rated) VI -0.3 VDD + 0.3 V Voltage on output pins (5 V rated) VO -0.3 5.5 V Voltage on output pins (3.3 V rated) VO -0.3 VDD + 0.3 V Storage temperature TSTG -55 150 °C Operating ambient temperature TOP -40 85 °C Junction temperature TJ 125 °C Power supply Note: Stresses exceeding these listed under absolute maximum ratings may induce failure. Exposure to absolute maximum ratings for extended periods may reduce reliability. Functionality at or above these conditions is not implied. 27 Zarlink Semiconductor Inc. ZL10354 5.3 Data Sheet DC Electrical Characteristics DC Electrical Characteristics Parameter Operating voltage Conditions Pins periphery core Supply current 1 1.62>CVDD>1.98 Symbol Min. Typ. Max. Unit VDD 3.0 3.3 3.6 V CVDD 1.62 1.8 1.98 IDDCORE Supply current sleep mode V 170 mA 300 µA Outputs Output levels IOH 2mA 3.0>VDD>3.6 IOL 2mA 3.0>VDD>3.6 IOL 6mA 3.0>VDD>3.6 Output capacitance MDO(7:0), MOVAL, MOSTRT, MOCLK, STATUS, BKERR GPP(3:0), DATA1, AGC1, AGC2, IRQ VOH 2.4 V VOL 0.4 V VOL 0.4 V Not including track MDO(7:0), MOVAL, MOSTRT, MOCLK, STATUS, BKERR GPP(3:0), DATA1, AGC1, AGC2,IRQ 3.0 pF 3.6 pF Output leakage (tri-state) 1 µA Inputs Input levels 3.0>VDD>3.6 -0.5 ≥ Vin ≥ VDD+0.5V Input levels Input levels Input leakage Current Input capacitance Input capacitance MICLK, SADD(4:0) SLEEP, OSCMODE VIH 2.0 V GPP(3:0), CLK1, 3.0>VDD>3.6 -0.5 ≥ Vin ≥ +5.5V DATA1, RESET VIH 2.0 V 3.0>VDD>3.6 All inputs VIL Capacitances do not include track SLEEP, SMTEST, MICLK, CLK1, OSCMODE SADD(4:0), DATA1, GPP(3:0) 1. Current given is for optimum performance, lower current is possible with reduced performance. 5.4 Crystal Specification and External Clocking Parallel resonant fundamental frequency (preferred) Tolerance over operating temperature range Tolerance overall Typical load capacitance Drive level Equivalent series resistance 20.4800 MHz ± 150 ppm ± 200 ppm 27 pF 0.4 mW max <25 Ω 28 Zarlink Semiconductor Inc. 0.8 V ±1 µA 1.8 pF 3.6 pF ZL10354 XTI Data Sheet XT0 OSCMODE XTI C1 C2 Figure 14 - Crystal Oscillator Circuit 5.4.1 Selection of External Components The capacitor values used must ensure correct operation of the Pierce oscillator such that the total loop gain is greater than unity. Correct selection of the two capacitors is very important and the following method is recommended to obtain values for C1 and C2. 5.4.1.1 Loop Gain Equation Although oscillation may still occur if the loop gain is just above 1, a loop gain of between 5 and 25 is optimum to ensure that oscillations will occur across all variations in temperature, process and supply voltage, and that the circuit will exhibit good start-up characteristics. Equation 1 - -A= Equation 2 - - Zin = 5.4.1.2 Cout.gm Cout + Cin Cin Rf.Cin + 1 Zin + 1 -1 Zo 1 (2.π.f.Cout)2.ESR List of Equation Parameters A total loop gain (between 5 and 25) Cin C1 + Cpar Cout C2 + Cpar Cpar parasitic capacitance associated with each oscillator pin (XTI and XTO). It consists of track capacitances, package capacitance and cell input capacitance. Normally Cpar ≈ 4pF. Zo 9.143 kΩ - output impedance of amplifier at 1.8 V operation - typical gm 8.736 mA/V - transconductance of amplifier at 1.8 V operation -typical Rf 2.3 MΩ - internal feedback resistor ESR maximum equivalent series resistance of crystal - given by crystal manufacturer (Ω) f fundamental frequency of crystal (Hz) 29 Zarlink Semiconductor Inc. ZL10354 5.4.1.3 Data Sheet Calculating Crystal Power Dissipation To calculate the power dissipated in a crystal the following equation can be used. Equation 3 - Pc = Vpp2 8.Zin Pc = power dissipated in crystal at resonant frequency (W) Vpp = maximum peak to peak output swing of amplifier is 1.8 V for all CVDD Zin = crystal network impedance (see Equation 2) 5.4.1.4 Capacitor Values Using the loop gain limits (5 < A < 25), the maximum and minimum values for C1 and C2 can be calculated with Equation 4 below. Equation 4 - Cin = Cout = 2 1 . 1 gm A Rf Zo (2.π.f)2.ESR when: C1 = C2 = Cout - Cpar Note: Equation 4 was derived from Equation 1 and Equation 2 using the premise that C1 = C2. Within these limits, any value for C1 and C2 can now be selected. Normally C1 and C2 are chosen such that the resulting crystal load capacitance CL (see Equation 5) is close to the crystal manufacturers recommended CL (standard values for CL are 15 pF, 20 pF and 30 pF). The crystal will then operate very near its specified frequency. Equation 5 - - CL = Cout . Cin Cout + Cin + Cpar12 Cpar12 = parasitic capacitance between the XTI and XTO pins. It consists of the IC package’s pin-to-pin capacitance (including any socket used) and the printed circuit board’s track-to-track capacitance. Cpar12 ≈ 2pF. If some frequency pulling can be tolerated, a crystal load capacitance different from the crystal manufacturer’s recommended CL may be acceptable. Larger values of CL tend to reduce the influence of circuit variations and tolerances on frequency stability. Smaller values of CL tend to reduce startup time and crystal power dissipation. Care must however be taken that CL does not fall outside the crystal pulling range or the circuit may fail to start up altogether. It is also possible to quote CL to the crystal manufacturer who can then cut a crystal to order which will resonate, under the specified load conditions, at the desired frequency. Finally the power dissipation in the crystal must be checked. If Pc is too high C1 and C2 must be reduced. If this is not feasible C2 alone may be reduced. Unbalancing C1 and C2 will, however, require checking if the loop gain condition is still satisfied. This must be done using Equation 1. C2 Note: 2 > > 0.5 C1 30 Zarlink Semiconductor Inc. ZL10354 5.4.1.5 Data Sheet Oscillator/Clock Application Notes • On the printed circuit board, the tracks to the crystal and capacitors must be made as short as possible. Other signal tracks must not be allowed to cross through this area. The component tracks should preferably be ringed by a ground track connected to the chip ground (0 V) on adjacent pins either side of the crystal pins. It is also advisable to provide a ground plane for the circuit to reduce noise. • External clock signals, applied to XTI and/or XTO, must not exceed the cell supply limits (i.e., 0V and CVDD) and current into or out of XTI and/or XTO must be limited to less than 10mA to avoid damaging the cell’s amplitude clamping circuit. • An external, DC coupled, single ended square wave clock signal may be applied to XTI if OSCMODE = 0. To limit the current taken from the signal source a resistor should be placed between the clock source and XTI. The recommended value for this series resistor is 470 Ω for a clock signal switching between 0 V and CVDD. The current the clock source needs to source/sink is then <1.9 mA. The XTO pin must be left unconnected in this configuration. • AC coupling of a single ended external clock to XTI, with OSCMODE = 0, is not recommended. The duty cycle of the OSCOUT signal cannot be guaranteed in such a configuration. • AC coupling of a single ended external clock to XTI, with OSCMODE = 1, is possible. It is recommended that the circuit shown in Figure 15 be used to correctly bias the oscillator inputs: The common-mode voltage VCM for XTI and XTO, (set by the 36 kΩ and 22 kΩ resistors) must be 800 mV < VCM < CVDD and the amplitude Vpp of the clock signal must be >100 mV. XTO XTI Vdd OSCMODE 36k 10nF 100k External clock 10nF 22k Figure 15 - External Clocking via AC Coupling • External, differential clock signals may be applied to XTI and XTO if OSCMODE = 1. The common-mode voltage VCM for the differential clock signals must be 800 mV < VCM < CVDD, and the peak-to-peak signal amplitude Vpp must be >100 mV. It is recommended that differential clock signals have VCM = 1.0V. For Vpp > 400 mV a resistor of >390 Ω in series with XTI or XTO may be required to limit the current taken from or supplied to the clock sources. 31 Zarlink Semiconductor Inc. ZL10354 6.0 Application Circuit Figure 16 - Typical Application Circuit 32 Zarlink Semiconductor Inc. Data Sheet For more information about all Zarlink products visit our Web Site at www.zarlink.com Information relating to products and services furnished herein by Zarlink Semiconductor Inc. or its subsidiaries (collectively “Zarlink”) is believed to be reliable. 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