ZARLINK ZL10355QCF

ZL10355
Nordig Unified DVB-T COFDM
Terrestrial Demodulator for PC-TV
and Hand-held Digital TV (DTV)
Data Sheet
Features
August 2005
•
Compliant with ETSI 300 744 DVB-T, Unified
Nordig and DTG performance specifications
•
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
•
Digital filtering of adjacent channels
•
Single 8 MHz SAW filter for 6, 7 & 8 MHz OFDM
•
Superior single frequency network performance
•
Fast AGC to track out signal fades
Applications
•
Good 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
Ordering Information
ZL10355QCG
ZL10355QCG1
ZL10355QCF
ZL10355QCF1
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
•
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 ZL10355 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.
ZL10355
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 ZL10355 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 ZL10355 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.
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Zarlink Semiconductor Inc.
ZL10355
Data Sheet
Table of Contents
1.0 Pin & Package Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Pin Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Pin Allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.0 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Analog-to-Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Automatic Gain Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3 IF to Baseband Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4 Adjacent Channel Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.5 Interpolation and Clock Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.6 Carrier Frequency Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.7 Symbol Timing Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.8 Fast Fourier Transform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.9 Common Phase Error Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.10 Channel Equalization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.11 Impulse Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.12 Transmission Parameter Signalling (TPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.13 De-Mapper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.14 Symbol and Bit De-Interleaving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.15 Viterbi Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.16 MPEG Frame Aligner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.17 De-interleaver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.18 Reed-Solomon Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.19 De-scrambler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.20 MPEG Transport Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.0 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1 2-Wire Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1.1 Host . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1.2 Tuner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1.3 Examples of 2-Wire Bus Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.1.4 Primary 2-Wire Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2 MPEG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2.1 Data Output Header Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2.2 MPEG Data Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2.3 MPEG Output Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2.4 MOCLKINV = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.2.5 MOCLKINV = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.0 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.1 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2 Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.3 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.4 Crystal Specification and External Clocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.4.1 Selection of External Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.4.1.1 Loop Gain Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.4.1.2 List of Equation Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.4.1.3 Calculating Crystal Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.4.1.4 Capacitor Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.4.1.5 Oscillator/Clock Application Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.0 Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
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Zarlink Semiconductor Inc.
ZL10355
1.0
Pin & Package Details
1.1
Pin Outline
Figure 2 - Pin Outline
4
Zarlink Semiconductor Inc.
Data Sheet
ZL10355
1.2
Data Sheet
Pin Allocation
Pin
Function
Pin
Function
Pin
Function
Pin
Function
1
Vss
17
SADD1
33
Vdd
49
MDO0
2
Vdd
18
SADD0
34
RFLEV
50
MDO1
3
Vss
19
CVdd
35
CLK2/GPP0
51
MDO2
4
CLK1
20
Vss
36
DATA2/GPP1
52
MDO3
5
DATA1
21
PLLVdd
37
CVdd
53
MDO4
6
IRQ
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
57
MDO6
10
SLEEP
26
PLLTEST
42
AGC1
58
MDO7
11
STATUS
27
OSCMODE
43
GPP3
59
CVdd
28
AVdd
44
SMTEST
60
Vss
12
13
Vdd
29
AGnd
45
Vdd
61
MOCLK
14
Vss
30
VIN
46
Vss
62
BKERR
15
31
VIN
47
MOSTRT
63
MICLK
16
32
AGnd
48
MOVAL
64
CVdd
Table 1 - Pin Names - numeric
Function
Pin
Function
Pin
Function
Pin
Function
Pin
AGC1
42
GPP3
43
PLLTEST
26
Vdd
54
AGC2/GPP2
41
IRQ
6
PLLVdd
21
VIN
30
AGnd
29
MDO0
49
RESET
9
VIN
31
AGnd
32
MDO1
50
RFLEV
34
Vss
1
AVdd
28
MDO2
51
SADD0
18
Vss
3
BKERR
62
MDO3
52
SADD1
17
Vss
8
CLK1
4
MDO4
53
N/C
16
Vss
14
CLK2/GPP0
35
MDO5
56
N/C
15
Vss
20
CVdd
7
MDO6
57
N/C
12
Vss
25
CVdd
19
MDO7
58
SLEEP
10
Vss
38
CVdd
37
MICLK
63
SMTEST
44
Vss
40
CVdd
39
MOCLK
61
STATUS
11
Vss
46
Table 2 - Pin Names - alphabetical order
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Zarlink Semiconductor Inc.
ZL10355
Data Sheet
CVdd
59
MOSTRT
47
Vdd
2
Vss
55
CVdd
64
MOVAL
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
MPEG data valid
O
3.3
1
49-53, 56-58
MDO(0:4)/MDO(5:7)
MPEG data bus
O
3.3
1
61
MOCLK
MPEG clock out
O
3.3
1
62
BKERR
Block error
O
3.3
1
63
MICLK
MPEG clock in
I
11
STATUS
Status output
O
6
IRQ
Interrupt output
O
4
CLK1
Serial clock
5
DATA1
23
XTI
24
XTO
10
SLEEP
Device power down
I
12, 15-18
SADD(4:0)
Serial address set
I
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
6
O
3.3
CMOS
3.3
44
SMTEST
Production test (only set low)
I
3.3
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)
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Zarlink Semiconductor Inc.
Open drain
ZL10355
Data Sheet
Pin Description Table (continued)
Pin No
Name
Pin Description
I/O
Type
V
Analog inputs
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
Supply pins
2nd ADC supply
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Zarlink Semiconductor Inc.
mA
ZL10355
2.0
Data Sheet
Functional Description
A functional block diagram of the ZL10355 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.
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Zarlink Semiconductor Inc.
ZL10355
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 ZL10355 have been optimized to minimize power consumption.
2.1
Analog-to-Digital Converter
The ZL10355 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.
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Zarlink Semiconductor Inc.
ZL10355
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 ZL10355 used to minimize acquisition time. A robust AGC lock
mechanism is provided and the other parts of the ZL10355 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 ZL10355 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
ZL10355 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 ZL10355 register (defaults are for 45 MHz sampling and 8 MHz OFDM). The clock recovery
phase locked loop in the ZL10355 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.
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Zarlink Semiconductor Inc.
ZL10355
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
ZL10355 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
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.
2.14
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.
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Zarlink Semiconductor Inc.
ZL10355
2.15
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.
2.16
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.
2.17
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.
2.18
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 ZL10355 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.
2.19
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.
2.20
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 ZL10355
with a clock provided by the user.
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Zarlink Semiconductor Inc.
ZL10355
3.0
Interfaces
3.1
2-Wire Bus
3.1.1
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 ZL10355 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 ZL10355 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.
3.1.2
Tuner
The ZL10355 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.
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Zarlink Semiconductor Inc.
ZL10355
3.1.3
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
ZL10355 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 - ZL10355 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 - ZL10355 as a slave transmitter:
S
DEVICE
W
A
RADD
ADDRESS
3.1.4
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 5 - Primary 2-Wire Bus Timing
Where:
P
S = Start
Sr = Restart, i.e., start without stopping first.
P = Stop.
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Zarlink Semiconductor Inc.
t SU;STO
ZL10355
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
Table 3 - 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.
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Zarlink Semiconductor Inc.
kHz
ns
ZL10355
3.2
3.2.1
Data Sheet
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 6 - 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).
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Zarlink Semiconductor Inc.
ZL10355
3.2.2
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 7 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 7 - MPEG Output Data Waveforms
3.2.3
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.
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Zarlink Semiconductor Inc.
ZL10355
3.2.4
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 8 - MPEG Timing - MOCLKINV = 1
3.2.5
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 9 - MPEG Timing - MOCLKINV = 0
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Zarlink Semiconductor Inc.
ZL10355
4.0
Electrical Characteristics
4.1
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.
4.2
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.
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Zarlink Semiconductor Inc.
ZL10355
4.3
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.
4.4
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
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Zarlink Semiconductor Inc.
0.8
V
±1
µA
1.8
pF
3.6
pF
ZL10355
XTI
Data Sheet
XT0
OSCMODE
XTI
C1
C2
Figure 10 - Crystal Oscillator Circuit
4.4.1
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.
4.4.1.1
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 =
4.4.1.2
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)
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Zarlink Semiconductor Inc.
ZL10355
4.4.1.3
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)
4.4.1.4
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
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ZL10355
4.4.1.5
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 11 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 11 - 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.
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Zarlink Semiconductor Inc.
ZL10355
5.0
Application Circuit
Figure 12 - Typical Application Circuit
24
Zarlink Semiconductor Inc.
Data Sheet
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However, Zarlink assumes no liability for errors that may appear in this publication, or for liability otherwise arising from the application or use of any such
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This publication is issued to provide information only and (unless agreed by Zarlink in writing) may not be used, applied or reproduced for any purpose nor form part
of any order or contract nor to be regarded as a representation relating to the products or services concerned. The products, their specifications, services and other
information appearing in this publication are subject to change by Zarlink without notice. No warranty or guarantee express or implied is made regarding the
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any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user’s responsibility to fully determine the performance and
suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. Manufacturing does
not necessarily include testing of all functions or parameters. These products are not suitable for use in any medical products whose failure to perform may result in
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Purchase of Zarlink’s I2C components conveys a licence under the Philips I2C Patent rights to use these components in and I2C System, provided that the system
conforms to the I2C Standard Specification as defined by Philips.
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TECHNICAL DOCUMENTATION - NOT FOR RESALE