The Digital Costas Loop (DCL) performs many of the
baseband processing tasks required for the demodulation of
BPSK, QPSK, 8-PSK, OQPSK, FSK, AM and FM
waveforms. These tasks include matched filtering, carrier
tracking, symbol synchronization, AGC, and soft decision
slicing. The DCL is designed for use with the HSP50110
Digital Quadrature Tuner to provide a two chip solution for
digital down conversion and demodulation.
The DCL processes the In-phase (I) and Quadrature (Q)
components of a baseband signal which have been digitized
to 10 bits. As shown in the block diagram, the main signal
path consists of a complex multiplier, selectable matched
filters, gain multipliers, cartesian-to-polar converter, and soft
decision slicer. The complex multiplier mixes the I and Q
inputs with the output of a quadrature NCO. Following the
mix function, selectable matched filters are provided, which
perform integrate and dump or root raised cosine filtering
(α ~ 0.40). The matched filter output is routed to the slicer,
which generates 3-bit soft decisions, and to the cartesian-topolar converter, which generates the magnitude and phase
terms required by the AGC and Carrier Tracking Loops.
The PLL system solution is completed by the HSP50210
error detectors and second order Loop Filters that provide
carrier tracking and symbol synchronization signals. In
applications where the DCL is used with the HSP50110,
these control loops are closed through a serial interface
between the two parts. To maintain the demodulator
performance with varying signal power and SNR, an internal
AGC loop is provided to establish an optimal signal level at
the input to the slicer and to the cartesian-to-polar converter.
FN3652.5
Features
• Clock Rates Up to 52MHz
• Selectable Matched Filtering with Root Raised Cosine or
Integrate and Dump Filter
• Second Order Carrier and Symbol Tracking Loop Filters
• Automatic Gain Control (AGC)
• Discriminator for FM/FSK Detection and Discriminator
Aided Acquisition
• Swept Acquisition with Programmable Limits
• Lock Detector
• Data Quality and Signal Level Measurements
• Cartesian-to-Polar Converter
• 8-Bit Microprocessor Control - Status Interface
• Designed to Work With the HSP50110 Digital Quadrature
Tuner
• 84 Lead PLCC
• Pb-Free Available (R oH S compliant)
Applications
• Satellite Receivers and Modems
• BPSK, QPSK, 8-PSK, OQPSK, FSK, AM and FM
Demodulators
• Digital Carrier Tracking
• Related Products: HSP50110 Digital Quadrature Tuner,
D/A Converters HI5721, HI5731, HI5741
• HSP50110/210EVAL Digital Demod Evaluation Board
Block Diagram
CARRIER
TRACK
CONTROL
HI/LO
I SER OR
(9-0)
I
IN
SERCLK
OR CLK
Q SER OR
Q
(9-0)
IN
SYMBOL
TRACK
CONTROL
CONTROL/
STATUS
BUS
(COF)
LEVEL
DETECT
(SOF)
COS
10
10
13
NCO
SIN
SYMBOL
TRACKING
LOOP FILTER
1
CARRIER ACQ/TRK
LOOP FILTER
I
RRC
FILTER
Q
RRC
FILTER
CONTROL
INTERFACE
CARRIER PHASE
ERROR DETECT
LOOP
FILTER
INTEGRATE/
DUMP
INTEGRATE/
DUMP
SYMBOL
PHASE
ERROR
DETECT
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
LEVEL
DETECT
8
CARTESIAN
8
| Intersil (and design) is a registered trademark of Intersil Americas Inc.
All other trademarks mentioned are the property of their respective owners.
LOCK
DETECT
MAGNITUDE
8
PHASE
TO
POLAR
Copyright Intersil Americas Inc. 2000, 2008. All Rights Reserved
PART NUMBERPART MARKINGTEMP. RANGE (°C)PACKAGEPKG. DWG. #
HSP50210JC-52HSP50210JC-520 to +7084 Ld PLCCN84.1.15
HSP50210JC-52Z (Note)HSP50210JC-52Z0 to +7084 Ld PLCC (Pb-free)N84.1.15
HSP50210JI-52HSP50210JI-52-40 to +8584 Ld PLCCN84.1.15
HSP50210JI-52Z (Note)HSP50210JI-52Z-40 to +8584 Ld PLCC (Pb-free)N84.1.15
NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100%
matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil
Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
2
FN3652.5
July 2, 2008
HSP50210
www.BDTIC.com/Intersil
Pin Description
NAMETYPEDESCRIPTION
VCC -+5V Power Supply.
GND-Ground.
IIN9-0IIn-Phase Parallel Input. Data may be two’s complement or offset binary format (see Table 15). These inputs are
sampled by CLK when the SYNC
QIN9-0IQuadrature Parallel Input. Data may be two’s complement or offset binary format (see Table 15). These inputs are
sampled by CLK when the SYNC
SYNC
COFOCarrier Offset Frequency. The frequency term generated by the Carrier Tracking Loop Filter is output serially via this
COFSYNCOCarrier Offset Frequency Sync. This signal is asserted one CLK or SLOCLK cycle before the MSB of the serial data
SOF OSampler Offset Frequency. Sample frequency correction term generated by the Symbol Tracking Loop Filter is
SOFSYNCOSampler Offset Frequency Sync. This signal is asserted one CLK or SLOCLK cycle before the MSB of the serial data
A2-0IAddress Bus. The address on these pins specify a target register for reading or writing (see “Microprocessor
C7-0I/OMicroprocessor Interface Data Bus. This bi-directional bus is used for reading and writing to the processor interface.
WR
RD
IData Sync. When SYNC is asserted “Low”, data on IIN9-0 and QIN9-0 is clocked into the processing pipeline by the
rising edge of CLK.
pin. The new offset frequency is shifted out MSB first by CLK or SLOCLK starting with the clock cycle after the
assertion of COFSYNC.
word. (Programmable Polarity, see Table 42 on page 42, Bit 11).
output serially via this pin. The frequency word is shifted out MSB first by CLK or SLOCLK starting with the clock
cycle after assertion of SOFSYNC.
word. (Programmable Polarity, see Table 42 on page 42, Bit 12).
Interface” on page 27). A0 is the LSB.
These are the data I/O pins for the processor interface. C0 is the LSB.
IWrite. This is the write strobe for the processor interface (see “Microprocessor Interface” on page 27).
IRead. This is the read enable for the processor interface (see “Microprocessor Interface” on page 27).
signal is active Low. IIN9 is the MSB. See “Input Controller” on page 6.
signal is active Low. QIN9 is t heMSB. “Input Controller” on page 6.
FZ_STIFreeze Symbol Tracking Loop. Asserting this pin “high” zeroes the sampling error into the Symbol Tracking Loop
FZ_CTIFreeze Carrier Tracking Loop. Asserting this pin “high” zeroes the carrier Phase Error input to the Carrier Tracking
LKINTOLock Detect Interrupt. This pin is asserted “high” for at least 4 CLK cycles when the Lock Detector Integration cycle
THRESH
SLOCLKOSlow Clock. Optional serial clock used for outputting data from the Carrier and Symbol Tracking Loop Filters. The
ISERIIn-Phase Serial Input. Serial data input for In-Phase Data. Data on this pin is shifted in MSB first and is synchronous
QSERIQuadrature Serial Input. Serial data input for Quadrature Data. Data on this pin is shifted in MSB first and is
SSYNCISerial Word Sync. This input is asserted “high” one CLK before the first data bit of the serial word (see Figure 2).
SERCLKISerial Clock. May be asynchronous to other clocks. Used to clock in serial data (see “Input Controller” on page 6).
AOUT9 -0OA Output. Data on this output depend on the configuration of Output Selector. AOUT9 is the MSB (see Table 43 on
BOUT9-0OB Output. Data on this output depend on the configuration of Output Selector. BOUT9 is the MSB (see T able 43 page 44).
SMBLCLKOSymbol Clock. 50% duty cycle clock aligned with soft bit decisions (see Figure 19).
Filter (see “Symbol Tracking Loop Filter” on page 17).
Loop Filter.
is finished (see “Lock Detector” on page 23). Used as an interrupt for a pr ocessor. The Lock Detect Interrupt may
be asserted “high” longer than 4 CLK cycles, depending on the Lock Detector mode.
OThreshold Exceeded. This output is asserted “low” when the magnitude out of the Cartesian to Polar converter
exceeds the programmable Power Detect Threshold (see Table 16 on page33 and “AGC” on page 10).
clock is programmable and has a 50% duty cycle. Note: Not used when the HSP50110 is used with the HSP50210
(see Table 42 page 42).
to SERCLK (see “Input Controller” on page 6).
synchronous to SERCLK (see “Input Controller” on page 6).
page 44).
3
FN3652.5
July 2, 2008
HSP50210
www.BDTIC.com/Intersil
Pin Description (Continued)
NAMETYPEDESCRIPTION
OEAIA Output Enable. This pin is the three-state control pin for the AOUT9-0. When OEA is high, the AOUT9-0 is high
impedance.
OEB
HI/LO
CLKISystem Clock. Asynchronous to the processor interface and serial inputs.
IB Output Enable. This pin is the three-state control pin for the BOUT9-BOUT0. When OEB is high, the AOUT9-0 is
high impedance.
0HI/LO. The output of the Input Level Detector is provided on this pin (see “Input Level Detector” o n page 6). This
signal can be externally averaged and used to control the gain of an amplifier to close an AGC loop around the A/D
converter. This type of AGC sets the level based on the median value on the input.
4
FN3652.5
July 2, 2008
AGC
www.BDTIC.com/Intersil
LOOP
HI/LO
SYNC
5
IIN9-0
QIN9-0
SSYNC
SERCLK
ISER
QSER
LEVEL
DETECT
INPUT CONTROLLER
SYNTHESIZER/
I
Q
MIXER
COS
NCO
MATCHED FILTERING
M
U
X
M
U
X
SIN
RRC
RRC
M
U
X
M
U
X
FILTER
I AND D
I AND D
GAIN ERROR
DETECT
M
U
X
M
U
X
CARTESIAN
TO
POLAR
I2+Q
Q
TAN-1( )
SLICER
2
I
THRESH
SMBLCLK
SYMBOL TRACKING
SOFSYNC
SOF
COFSYNC
COF
SLOCLK
C7-0
A2-0
CLK
FRZ_ST
FRZ_CT
July 2, 2008
FN3652.5
8
WR
RD
SERIAL
OUTPUT
FORMATTER
MICROPROCESSOR
INTERFACE
FROM
LOCK
DETECTOR
ACQUISITION
CONTROL
FIGURE 1. FUNCTIONAL BLOCK DIAGRAM OF THE HSP50210
2ND ORDER LOOP
FILTER
CARRIER TRACKING
2ND ORDER LOOP
FILTER
SYMBOL PHASE
ERROR DETECT
CARRIER PHASE
ERROR DETECT
DISCRIMINATOR
FREQUENCY
ERROR DETECT
LOCK
DETECT
AOUT9-0
BOUT9-0
OEA
OEB
d
dt
LKINT
HSP50210
HSP50210
www.BDTIC.com/Intersil
Functional Description
The HSP50210 Digital Costas Loop (DCL) contains most of
the baseband processing functions needed to implement a
digital Costas Loop Demodulator. These functions include
LO generation/mixing, matched filtering, AGC, carrier phase
and frequency error detection, timing error detection, carrier
loop filtering, bit sync loop filtering, lock detection,
acquisition/tracking control, and soft decision slicing for
forward error correction algorithms. While the DCL is
designed to work with the HSP50110 Digital Quadrature
Tuner (DQT) as a variable rate PSK demodulator for satellite
demodulation, functions on the chip are common to many
communications receivers.
The DCL provides the processing blocks for the three
tracking loops commonly found in a data demodulator: the
Automatic Gain Control (AGC) loop, the Carrier Tracking
Loop, and a Symbol Tracking Loop. The AGC loop adjusts
for input signal power variations caused by path loss or
signal-to-noise variations. The carrier tracking loop removes
the frequency and phase uncertainties in the carrier due to
oscillator inaccuracies and doppler. The symbol tracking
loop removes the frequency and phase uncertainties in the
data and generates a recovered clock synchronous with the
received data. Each loop consists of an error detector , a loop
filter, and a frequency or gain adjustment/control. The AGC
loop is internal to the DCL, while the symbol and carrier
tracking loops are closed external to the DCL. When the
DCL is used together with the HSP50110, the tracking loops
are closed around the baseband filtering to center the signal
in the filter bandwidth. In addition, the AGC function is
divided between the two chips with the HSP50110 providing
the coarse AGC, and the HSP50210 providing the fine or
final AGC.
A top level block diagram of the HSP50210 is shown in
Figure 1. This diagram shows the major blocks and the
multiplexers used to reconfigure the data path for various
architectures.
Input Controller
In-Phase (I) and Quadrature (Q) data enters the part through
the Input Controller. The 10-bit data enters in either serial or
parallel fashion using either two’s complement or offset
binary format. The input mode and binary format is set in the
Data Path Configuration Control Register, bits 14 and 15
(see Table 15 on page 32).
If Parallel Input mode is selected, I and Q data are clocked
into the part through IIN0-9 and QIN0-9 respectively. Data
enters the processing pipeline when the input enable
(SYNC
) is sampled “low” by the processing clock (CLK). The
enable signal is pipelined with the data to the various
processing elements to minimize pipeline delay where
possible. As a result, the pipeline delay through the AGC,
Carrier Tracking, and Symbol Tracking Loop Filters is
measured in CLKs; not input data samples.
If serial input mode is selected, the I and Q data enters via
the ISER and QSER pins using SERCLK and SSYNC. The
beginning of a serial word is designated by asserting
SSYNC ‘high’ one SERCLK prior to the first data bit, as
shown in Figure 2. On the following SERCLKs, data is
shifted into the register until all 10 bits have been input. Data
shifting is then disabled and the contents of the register are
held until the next assertion of SSYNC. The assertion of a
SSYNC transfers data into the processing pipeline, and the
Shift Register is enabled to accept new data on the following
SERCLK. When data is transferred to the processing
pipeline by SSYNC, a processing enable is generated which
follows the data through the pipeline. This enable allows the
delay through processing elements (like the loop filters) to be
minimized since their pipeline delay is expressed in CLKs
not SSYNC periods. Note: SSYNC should not be asserted for more than one SERCLK cycle.
SERCLK
SSYNC
ISER/QSER
NOTE: Data must be loaded MSB first.
FIGURE 2. SERIAL INPUT TIMING FOR ISER AND QSER INPUTS
MSB
SSYNC LEADS 1st DATA BIT
MSB
Input Level Detector
The Input Level Detector generates a one-bit error signal for
an external IF AGC filter and amplifier. The error signal is
generated by comparing the magnitude of the input samples
to a user programmable threshold. The HI/LO pin is then
driven “high” or “low” depending on the relationship of its
magnitude to the threshold. The sense of the HI/LO pin is
programmable so that a magnitude exceeding the threshold
can either be represented as a “high” or “low” logic state.
The Input Level Detector (HI/LO output) threshold and the
sense are set by the Data Path Configuration Control
Register bits 16 to 23 and 13 (see Table 15 page 32).
Note: The Inpu t Level Detector is typically not used in
applications which use the HSP50210 with the
HSP50110.
The high/low outputs can be integrated by an external loop
filter to close an AGC loop. Using this method, the gain of
the loop forces the median magnitude of the input samples
to the threshold. When the magnitude of half of the samples
is above the threshold (and half is below), the error signal is
integrated to zero by the loop filter. The magnitude of the
complex input is estimated using Equation 1:
Mag (I, Q)I0.375Q if I Q and>×+=
Mag (I, Q)Q0.375I if Q I>×+=
(EQ. 1)
6
FN3652.5
July 2, 2008
REGISTER ENABLE RATE
www.BDTIC.com/Intersil
@ = SYNC RATE
= TWICE SYMBOL RATE
*
! = SYMBOL RATE
BLANK = CLK RATE
MID AND END
SYMBOL SAMPLES
TO SYMBOL TRACKING
I
MID
I
END
Q
MID
Q
END
D
HI/LO
MATCHED FILTERING
7
REG
REG
DETECT
LEVEL
IIN9-0QIN9-0
NCO MIXER
COMPLEX
MULTIPLY
BYPASS
MIXER
BYPASS
R
E
G
R
E
M
G
U
X
R
R
E
E
G
G
R
R
E
E
G
G
@
@
RRC
15 TAP RRC
15 TAP RRC
M
U
R
R
X
E
E
G
G
R
R
E
E
G
G
R
R
L
E
E
I
G
G
M
R
R
I
E
E
T
G
G
DUMP
+
DUMP
+
M
U
X
DATA DE-SKEW
OQPSK
“0”
R
R
E
E
G
G
@
*
“0”
M
U
X
R
E
G
M
U
X
@
SIN
COS
REG REG
REG REG
SIN/COS
ROM
REG
+
REG
CF
REGISTER
ROOT RAISED COSINE
(RRC)
AGC LOOP FILTER
L
I
R
M
E
I
G
UPPER
GAIN
LIMIT
T
LOWER
GAIN
LIMIT
@ OR !
INTEGRATE AND DUMP
R
E
+
G
LOOP GAIN
EXPONENT
FALSE LOCK
COMPARE
S
H
I
F
T
*
TWO SAMPLE
SUMMER
S
H
F
T
R
E
I
G
*
S
R
H
E
I
G
F
T
LOOP GAIN
MANTISSA
REG
R
E
G
BYPASS
I AND D
+
M
U
X
+
HOLD AGC
M
U
X
E
M
U
X
D
E
M
U
X
M
U
X
AGC ERROR DETECT
“0”
AGC THRESHOLD
GAIN
ERROR
POWER
THRESHOLD
CARTESIAN TO
POLAR
2
DELAY
I2+Q
Q
-1
TAN
( )
DELAY
I
PHASE OUT AT
MAG OUT AT
-
+
COMPARE
SOFT
DECISION
SLICER
TEST
M
U
X
5
REG
5
REG
@ OR
@ OR !
R
E
G
R
E
G
R
E
G
R
E
G
O
R
U
E
**
T
G
P
R
U
! OR! OR
E
T
G
S
E
L
E
8
C
T
8
AOUT9-0BOUT9-0
R
E
G
R
E
G
HSP50210
*
TO
CARRIER
TRACKING
AND
DISCRIMINATOR
THRESH
R
E
G
FROM CARRIER TRACKING
LOOP FILTER
July 2, 2008
FN3652.5
FIGURE 3. MAIN DATA PATH
HSP50210
www.BDTIC.com/Intersil
NCO/Mixer
The NCO/Mixer performs a complex multiply between the
baseband input and the output of a quadrature NCO
(Numerically Controlled Oscillator). When the HSP50210
(DQT) is used with the HSP50110 (DCL), the NCO/Mixer
shortens the Carrier Tracking Loop (i.e., minimizes pipeline
delay around the loop) while providing wide loop
bandwidths. This becomes important when operating at
symbol rates near the maximum range of the part.
There are three configurations possible for closing the
Carrier Tracking Loop when the DQT and the DCL are used
together. The first configuration utilizes the NCO on the DQT
and bypasses the NCO in the DCL. The Data Path
Configuration Control Register (see Table 15 on page 32),
Bit 10, and Carrier Loop Filter Control Register #1
(see Table 21 on page 34), Bit 6, are used to bypass the
DCL NCO/Mixer and route the Loop filter outputs,
respectively. The DQT provides maximum flexibility in NCO
control with respect to frequency and phase offsets.
The second configuration feeds the lead Carrier Loop filter
term to the DCL NCO/Mixer, and the lag Loop filter Term to
the DQT NCO. This reduces the loop transport delay while
maintaining wide loop bandwidths and reasonable loop
damping factors. This configuration is especially useful in
SATCOM applications with medium to high symbol rates.
The Carrier Loop Filter Control Register #1, Bit 5 is where
the lead/lag destination is set.
The final configuration feeds both the lead and lag Carrier
Loop Filter terms back to the DCL NCO/Mixer. This provides
the shortest transport delay. The DCL NCO/Mixer provides
only for frequency/phase control from the Carrier Loop filter.
The center frequency of this NCO/Mixer is set to the average
of the Upper and Lower Carrier Loop Limits programmable
parameters. These parameters are set in the two control
registers bearing their names (see Tables 23 and 24 on
page 35).
The NCO/Mixer uses a complex multiplier to multiply the
baseband input by the output of a quadrature NCO. This
operation is represented by Equations 2 and 3:
I
OUTIIN
Q
OUTIIN
Equation 3 illustrates how the complex multiplier implicitly
performs the summing function when the DCL is configured
as a modulator. The quadrature outputs of the NCO are
generated by driving a sine/cosine look-up table with the
output of a phase accumulator, as shown in Figure 3 on
page 7. Each time the phase accumulator is clocked, its sum
is incremented by the contents of the Carrier Frequency (CF)
Register. As the accumulator sum increments from 0 to 2
the SIN/COS ROM produces quadrature outputs whose
phase advances from 0 to 360°. The CF Register contains a
ωC()cosQ
ωC()sinQ
IN
IN
ωC()sin–=
ωC()cos+=
(EQ. 2)
(EQ. 3)
32
32-bit phase increment, which is updated with the output of
Carrier Tracking Loop. Large phase increments take fewer
clocks to step through the sine wave cycle, which results in a
higher frequency NCO output.
The CF Register sets the NCO frequency using Equation 4:
F
CfCLK
CFINT F
where f
complement hexadecimal value loaded into the Carrier
Frequency Register. As an example, if the CF Register is
loaded with a value of 4000 0000 (Hex), and the CLK
frequency is 40MHz, the NCO would produce quadrature
terms with a frequency of 10MHz. When CF is a negative
value, a clockwise cos/sin vector rotation is produced. When
CF is positive, a counterclockwise vector rotation is
produced.
Note: The NCO is set to a fixed frequency by programming
the upper and lower limits of the Carrier Tracking Loop Filter
to the same value and zeroing the lead gain.
×=
32
⁄()2
[]H=
CfCLK
is the CLK frequency, and CF is the 32-bit two’s
CLK
32
CF()2⁄
(EQ. 4)
Matched Filtering
The HSP50210 provides two selectable matched filters: a
Root Raised Cosine Filter (RRC) and an Integrate and Dump
(I and D) filter. These are shown in Figure 3. The RRC filter
is provided for shaped data pulses and the I and D filter is
provided for square wave data. The filters may be cascaded
for better adjacent channel rejection for square wave data. If
these two filters do not meet baseband filtering
requirements, then they can be bypassed and an external
digital filter (such as the HSP43168 Dual FIR Filter or the
HSP43124 Serial I/O Filter) used to implement the desired
matched filter. The desired filter configuration is set in the
Data Path Configuration Control Register, bits 1 through 7
(see Table 15 on page 32).
The sample rate of the baseband input depends on the
symbol rate and filtering configuration chosen. In
configurations which bypass both filters or use only the RRC
Filter, the input sample rate must be twice the symbol rate. In
configurations which use the I and D Filter, the input sample
rate is decimated by the I and D Filter, down to two samples
per symbol. I and D configurations support input sample
rates up to 32x the input symbol rate.
The RRC filter is a fixed coefficient 15 Tap FIR filter. It has
~40% excess bandwidth beyond Nyquist, which equates to
α = ~0.4 shape factor. The filter frequency response is
shown in Figures 4 and 5. In addition, the 9-bit filter
coefficients are listed as integer values in Table 1. The noise
,
equivalent bandwidth of the RRC filter and other filter
configurations possible with the HSP50110/210 chipset are
given in Appendix A.
8
FN3652.5
July 2, 2008
HSP50210
www.BDTIC.com/Intersil
0
-20
-40
-60
-80
NORMALIZED MAGNITUDE (dB)
-100
0
f
CLK
10
FREQUENCY (NORMALIZED TO INPUT SAMPLE RATE)
2f
CLK
10
3f
CLK
10
4f
CLK
10
f
CLK
2
FIGURE 4. RRC FILTER IN HSP50210
0
-0.18
-0.36
SHOWN BELOW
-0.54
-0.72
NORMALIZED MAGNITUDE (dB)
-0.90
0
0
-0.07
-0.14
-0.21
-0.28
NORMALIZED MAGNITUDE (dB)
-0.35
0
FREQUENCY (NORMALIZED TO INPUT SAMPLE RATE)
ENLARGED FOR CLARITY
f
CLK
20
2f
CLK
25
3f
f
CLK
f
CLK
25
40
CLK
40
3f
CLK
25
f
CLK
10
4f
CLK
25
5f
CLK
40
f
CLK
5
3f
CLK
20
FIGURE 5. PASSBAND RIPPLE OF RRC FILTER IN HSP50210
TABLE 1. ROOT RAISED COSINE COEFFICIENTS
COEFFICIENT INDEXCOEFFICIENT
02
1-2
21
38
4-16
5-14
686
7160
886
9-14
10-16
118
121
13-2
142
The I and D filter consists of an accumulator, a
programmable shifter and a two sample summer, as shown
in Figure 3. The programmable shifter is provided to
compensate for the gain introduced by the accumulator (see
Table 15). The accumulator provides Integrate and Dump
Filtering for decimation factors up to 16. The two sample
summer provides the moving average required for an
additional decimation factor of 2. A decimation factor of 1
(bypass), 2, 4, 8, 16, or 32 may be selected. At the maximum
decimation rate, a baseband signal sampled at 32x the
symbol rate can be filtered.
The output of the two sample summer is demultiplexed into
two sample streams at the symbol rate. The demultiplexed
data streams from the I and Q processing paths are fed to
the Symbol Tracking Block and Soft decision slicer. The
multiplexed data streams on I and Q are provided as one of
the selectable inputs for the Cartesian-to-Polar Converter.
Cartesian/Polar Converter
The Cartesian/Polar Converter maps samples on the I and Q
processing paths to their equivalent phase/magnitude
representation. The magnitude conversion is equivalent to
Equation 5:
Mag (I, Q)0.81()∗I2Q2+()=
where 0.81 is the gain of the conversion process. The
magnitude output is an 8-bit unsigned value ranging from 0.0
to 1.9922.
9
(EQ. 5)
FN3652.5
July 2, 2008
HSP50210
www.BDTIC.com/Intersil
The phase conversion is equivalent to Equation 6:
Phase (I, Q)tan
-1
where tan
( ) is the arctangent function. The phase
1–
QI⁄(),=
(EQ. 6)
conversion output is an 8-bit two’s complement output,
which ranges from -1.0 to 0.9922 (80 to 7f HE X,
respectively). The -1 to almost 1 range of the phase output
represents phase values from -π to π, respectively. An
example of the I/Q to phase mapping is shown in Figures 6A
through 6C. The phase and magnitude values may be output
via the Output Selector bits 0 through 3 (see Tab le 43).
1.0
0.5
0
MAGNITUDE
-0.5
-1.0
-π
FIGURE 6A. I INPUT TO CARTESIAN/POLAR CONVERTER
1.0
0.5
0
MAGNITUDE
-0.5
-1.0
-π
FIGURE 6B. Q INPUT TO CARTESIAN/POLAR CONVERTER
1.0
0
INPUT PHASE
0
INPUT PHASE
π/2π-π/2
π/2π-π/2
The I/Q data path selected for input to the Cartesian-to-Polar
converter determines the input data rate of the AGC and
carrier tracking loops. If the I/Q data path out of the Integrate
and Dump Filter is selected, the AGC is fed with magnitude
values produced by the end-symbol samples. Magnitude
values produced by midsymbol samples are not used
because these samples occur on symbol transitions, resulting
in poor signal magnitude estimates. The Carrier Tracking
block is fed with phase values generated from both the end
and mid-symbol samples. The carrier tracking loop filte r,
however, is only fed with Ph ase Erro r terms gen erate d by the
end symbol samples. If the input of the I and D is selected for
input to the coordinate converter , the control loops are fed with
data at the I/Q data rate. The desired dat a p a th input to the
Cartesian to Polar converter is specified in the Data Path
Configuration Control Register , Bit 8 (see Table 15 on
page 32).
AGC
The AGC loop operates on the main data path (I and Q) and
performs three signal level adjusting functions:
1. Maximizing dynamic range
2. Compensating for SNR variations
3. Maintaining an optimal level into the Soft Decision Slicer.
The AGC Loop Block Diagram, shown in Figure 7, consists
of an Error Detector, a Loop Filter, and Signal Gain Adjusters
(multipliers). The AGC Error Detector generates an error
signal by subtracting the programmable AGC threshold from
the magnitude output of the Cartesian to Polar Converter.
This difference signal is scaled (gain adjusted via multiplier
and shifter), then filtered (integrated) by the AGC Loop Filter
to generate the gain correction to the I and Q signals at the
multipliers. If a fixed gain is desired, set the upper and lower
limits equal.
The AGC responds to the magnitude of the sum of all the
signals in the bandpass of the narrowest filter preceding the
Cartesian to Polar Coordinate Converter. This filter may be
the Integrate and Dump filter shown in Figure 7 on page 12,
the RRC filter upstream in the HSP50210 data path, or some
other filter outside the DCL chip. The magnitude signal
usually contains several components:
0.5
2. The noise comp onent, and
3. Interfering signals component.
1. The signal of interest component,
0
At high SNR’s the signal of interest is significantly greater
than the other components. At lower SNR’s, components 2
-0.5
OUTPUT VOLTAGE
or 3 may become greater than the signal of interest.
Narrowing the filter bandwidth is the primary technique
-1.0
-π
0
INPUT PHASE
π/2π-π/2
used to mitigate magnitude contributions of component 3.
This will also improve the SNR by reducing the magnitude
contributions of element 2. Consideration of the range of
signal amplitudes expected into the HSP50210, in
FIGURE 6C. CARTESIAN/POLAR CONVERTER PHASE OUTPUT
conjunction with a gain distribution analysis, will provide the
10
FN3652.5
July 2, 2008
A
HSP50210
www.BDTIC.com/Intersil
necessary insight to set the signal level into the Soft
Decision Slicer to yield opti mum perf or ma nce .
Note: Failure to consider the variations due to noise or
interfering signals, can result in signal limiting in the
HSP50210 processing algorithms, which will degrade the
system Bit Error Rate performance.
The AGC Loop is configured by the Power Detect Threshold
and AGC Loop Parameters Control Registers (see Tables 16
and 17 on page 33). Seven programmable parameters must be
set to configure the AGC Loop and its status outputs. Two
parameters, the Power Threshold and the AGC Threshold are
associated with the Error Detector and are represented in 8-bit
fractional unsigned binary format: 2
02-12-22-32-42-52-62-7
.
While the format provides a range from 0 to 1.9961 for the
thresholds, the Cartesian-to-Polar Converter scales the I
and Q input magnitudes by 0.81. Thus, if a full scale (±1)
complex (I and Q) input signal is presented to the converter,
the output will be √(0.81)
2
+ (0.81)2 = 1.1455. The AGC
Threshold parameter value is the desired magnitude of the
signal as it enters the Soft Decision Slicer. It is the parameter
that will determine the error signal in the AGC loop. The
Power Threshold, on the other hand, determines only the
power threshold at which the THRESH
signal is asserted. If
the signal magnitude exceeds the threshold, then the
THRESH
is asserted. This may be used for signal detection,
power detection or external AGC around the A/D converter.
The AGC Threshold parameter is set in the AGC Loop
Parameters Control Register, Bits 16 through 23 (see
Table 17 on page 33). The Power Threshold parameter is
set in the Power Detect Threshold Control Register, Bits 0
through 7 (see Table 16 on page 33). Note that these two
threshold parameters are not required to be set to identical
or even related values, since they perform independent
functions.
The Enable AGC parameter sets the AGC Error Detector
output to zero if asserted and to normal error detection
output when not asserted. This control bit is set in the AGC
Loop Parameter Control Register, Bit 31 (see Tables 17 on
page 33). This bit is used to disable the AGC loop.
The remaining AGC parameters determine the AGC loop
characteristics: gain tracking, tracking rate and tracking limits.
The AGC Loop gain is set via two parameters: AGC Loop Gain
Exponent and AGC Loop Gain Mantissa. In general, the higher
the loop gain, the faster signal level acquisition and tracking,
but this must be tempered by the specific signal characteristics
of the application and the remaining programmable loop
parameters. For the HSP50210, the AGC Loop Gain provides
for a variable attenuation of t he input to the loop filter. The AGC
gain mantissa is a 4-bit value which provides error signal
scaling from 0.000 to 0.9375, with a resolution of 0.0625.
Table 2 on page 11 details the discrete set of decimal values
possible for the AGC Loop Gain mantissa. The exponent
-7
provides a shift factor scaling from 2
to 2
-14
. Table 3 on
page 11 details the discrete set of decimal values possible for
the AGC Loop Gain Exponent. When combined, the exponent
and mantissa provide a loop gain defined as Equation 7:
GC Loop Gain: G
AGC
M()24–()[]2
7E+()–
()[]=
(EQ. 7)
where M is a binary number with a range from 0 to 15 and E
is a 3-bit binary value from 0 to 7. M and E are the
parameters set in the AGC Loop Parameters Control
Register, Bits 24 through 30 (see Table 17 on page 33). The
composite range of the AGC loop Gain is 0.0000 to
[0.9375][2 to 7]. This will scale the AGC error signal to a
range of 0.000 to (1.1455)(0.9375)(2 to 7) = 1.07297(2 to 7).
The AGC Loop Filter integrates the scaled error signal to
provide a correction control term to the multipliers in the I and
Q path. The loop filter accumulator has internal upper and
lower limiters. The upper eight bits of the accumulator output
map to an exponent and mantissa format that is used to set
these upper and lower limits. The format, illustrated in Figure
8, is used for the AGC Upper Limit, AGC Lower Limit and the
Correction Control Term (AGC output). This format should not
be confused with the similar format used for the AGC Loop
Gain. The input to the AGC Loop Filter is included in Figure 8
to show the relative weighting of the input to output of the loop
filter. The loop filter input is represented as the eleve n letter
“G”s. Lower case “e” and “m” detail the format for the AGC
Upper and Lower Limits. This change in type case should help
keep the AGC Limits and AGC Gain formats from being
confused. The AGC Upper and Lower Limits are set in the
AGC Loop Parameters Control Register, Bit s 0 throu gh15,
(see Table 17). This 6-bit unsigned mantissa format provides
for an AGC output control range from 0.0000 to 0.9844, with a
resolution of 0.015625. The 2-bit exponent format provides an
AGC output control range from 1 to 8. The decimal values for
each of the 64 binary mantissa values is detailed in Table 4,
while Table 5 details the decimal value for the 4 exponent
values.
GAIN
M
U
X
“0”
ENABLE AGC †
The AGC Output is implemented in the multiplier according
to Equations 8 and 9.
where m and e are the binary values for mantissa and
exponent found in Ta bles 4 and 5.
Note: This format is identical to the format used to program
the AGC Upper and Lower Limits, but in this usage it is not a
programmed value. It is a representation of the digital AGC
output number, which is presented to the Gain Adjuster
(multipliers) to correct the gain of the I and Q data signals in
the main data path.
These equations yield a composite (mantissa and
exponent) AGC output range of 0.0000 to 1.9844(2
is a logarithmic range from 0dB to 24dB. Figure 9 has
graphed the results of Equations 8 and 9 for both the linear
and logarithmic equations. Figure 9 also has a linear
estimate of the logarithmic equation. This linear
approximation will be used in calculating the AGC response
time.
M
U
X
Out
Out
AGC ERROR DETECT
COMPARE
POWER
THRSHLD †
+
GAIN
ERROR
AGC THRSHLD †
CARTESIAN TO POLAR
G
1.0
AGC linear–
AGC dB–
I2+Q
TAN
20 log 1.0 m
R
E
THRESH
G
-
1.64
-----------=
-1
( )
dcloutlvlagc thresh
where dcloutlvl is the
2
2
Q
I
magnitude output expressed
in dB from Full Scale (dBFS)
There are two techniques for setting a fixed gain for the
AGC. The first is to set Control Word 2 Bit 31 = 1. This
precludes any error update of present AGC gain value. The
second is to set the upper and lower AGC limits to the
desired gain using Figure 9. The upper and lower limits
have the same value for this case.
The HSP50210 provides two mechanisms for monitoring
signal strength. The first, which involved the THRESH
signal, has already been described. The second
mechanism is via the Microprocessor Interface. The 8 most
significant bits of the AGC loop filter output can be read by
a microprocessor. Refer to the “Microprocessor Interface”
on page 27 for details of how to read this value. This AGC
value has the format describ ed i n Fi gur e 8.
AGC Bit Weighting and Loop Response
The AGC loop response is a function of the programmable
gain, the bit weightings inherent in the connection of each
element of the loop, the AGC Loop filter limits and the
magnitude of the input gain error step. Table 6 on page 14
details the bit weighting between each element of the AGC
Loop from the error detector through the weighting at the
gain adjuster in the signal path. The AGC Loop Gain sets the
growth rate of the sum in the loop filter accumulator. The
Loop filter output growth rate determines how quickly the
AGC loop traces the transfer function shown previously in
Figure 9. To calculate the rate at which the AGC can adjust
over a given period of time, a gain step is introduced to the
gain error detector and the amount of change that is
observed between clocks at the AGC Level Adjusters
(multipliers) is the AGC response time in dB per symbol.
This AGC loop will respond immediately with the greatest
correction term, then asymptotically approach zero
correction.
We begin calculation of the loop response with a full scale
error detector input of ±1. This error input is scaled by the
Cartesian to Polar converter, the error detecto r and th e AGC
GAIN (dB)
13
FN3652.5
July 2, 2008
HSP50210
www.BDTIC.com/Intersil
Loop Gain, accumulated in the loop filter , limited and output to
the gain adjusters. The AGC loop tries to make the error
correction as quickly as possible, but is limited by the AGC
Loop Gain and potentially, the AGC limits. The maximum
AGC response is the maximum gain adjustment made in any
given clock cycle. This involves applying maximum Loop gain
and setting the AGC limits as wide as possible. A calculation
using only exponent terms of the various gains will be
sufficient to yield a rough order of magnitude of the range of
the AGC Loop response. The results are shaded in the last
column of Table 6 on page 14 and provided in detail in
Equations 10 and 11.
AGC
LOOP
FILTER
GAIN BITS
KEPT
(rnd)SHIFT = 0SHIFT = 7
0••0-70.04688
0•G-140.000366
AGC
OUTPUT
AND AGC
LIMITS BIT
WEIGHT
RESOLUTION
AGC GAIN
(dB)
AGC Response
AGC Response
where (0.5) is the MSB of the 0.81 scaling in the Cartesian-to-Polar Coo rdinate Con verter, (0.5) is the MSB of the mantissa of the
Loop Gain, (2
10.5()±0.5()27–()24() 129–()24()±0.04688dB symbol time⁄===
is the maximum shift gain, and 24 is the maximum loop filter gain.
A similar procedure is used to calculate the minimum AGC response rate.
AGC Response
MIN
10.5()±0.5()2
14–
()24() 12
16–
()24()±0.000366dB symbol time⁄===
Thus, the expected range for the AGC rate is approximately 0.0004 to 0.0469dB/symbol time.
14
(EQ. 10)
(EQ. 11)
FN3652.5
July 2, 2008
SYNTHESIZER/
www.BDTIC.com/Intersil
MIXER
G = 1.0, 0.5 (NOTE 1)
PART
INPUT
(NOTE 4)
0
BINARY
POINT
-2
-1
2
AGC GAIN
MANTISSA
1.0 TO 1.9844
(0.0156 STEPS)
G = 1.0 - 1.9844*2
RRC
FILTER
G = 1.0, 1.13 (NOTE 2)
G
1
0
-2
-1
2
-2
0
2
-1
2
AGC
HSP50210
EXPONENT
0
3
TO 2
2
3
ACCUMULATOR
G = 1 TO 16
L
I
8
M
/
I
T
5
-2
4
2
3
2
2
2
1
2
0
2
-1
2
INT/DUMP
0
-2
-1
2
INTEGRATE AND
DUMP FILTER
INT/DUMP
SHIFTER
0 TO 2-4
G = 2
4
-2
3
2
2
2
1
2
0
2
-1
2
SAMPLE PAIR
SUMMER
G = 0.5, 1.0 (NOTE 3)
L
I
M
I
T
4
-2
3
2
2
2
1
2
0
2
-1
2
0
-2
-1
2
INPUT TO
SOFT DECISION
SLICER
AND
SYMBOL TRACKING
BLOCK
0
-2
-1
2
-9
2
INPUT TO CARTESIAN-TO-POLAR CONVERTER
-10
2
RND
IF AGC OUTPUT SELECTED
-10
2
RND
-9
2
-7
2
RND
INPUT TO CARTESIAN-TO-POLAR CONVERTER
-7
2
IF INT/DUMP OUTPUT SELECTED
-11
2
-6
2
-6
2
-7
2
NOTES:
1. If the Mixer is enabled, the result of the complex multiply is scaled by two (G = 0.5). If the mixer is bypassed, the data passes unmodified (G = 1.0).
2. If the Root Raised Cosine Filter is enabled, a gain of G = 1.13 is introduced. If the RRC filters bypassed, the gain is unity.
-7
3. If the integrate and Dump Filter is bypassed the Sample Pair summer has a gain of G = 1.0 and the 2
-bit position is set to 1. If the integrate
and dump is enabled, the sample pair sum is scaled by one half (G = 0.5).
4. The negative sign on the MSBs indicates use of 2’s complement data format.
FIGURE 10. GAIN DISTRIBUTION AND INTERMEDIATE BIT WEIGHTINGS
Gain Distribution
The gain distribution in the DCL is shown in Figure 10.
These gains consist of a combination of fixed,
programmable, and adaptive gains. The fixed gains are
introduced by processing elements such as the Mixer and
Square Root of Root Raised Cosine Filter. The adaptive
gains are set to compensate for variations in input signal
strength.
The main signal path, with processing block gains and path
bit weightings, is shown in Figure 10. The quadrature inputs
to the HSP50210 are 10-bit fractional two’s complement
numbers with relative bit weightings, as shown in Figure 10.
Following the AGC, the signal path is limited to 8 bits and
passed through the Integrate and Dump Filter en route to the
Soft Decision Slicer and Symbol Tracking Block. The I and D
Filter uses an accumulator together with a sample pair summer
to achieve the desired decimation rate. The I and D shifter is
provided to compensate for the gain introduced by the I and D
Accumulator. The accumulator introduces gain equal to the
decimation factor R, and the shifter gain can be set to 1/R. For
example, if the I and D Filter decimation of 16 is chosen, the I
and D Accumulator will accumulate 8 samples before dumping,
which produces a gain of 8. Thus, for unity gain, the I and D
Shifter would be set for a gain of 2
-3
. The Sample Pair Summer
is unity gain since its output is scaled by one-half.
The first element in the processing chain is the Mixer, which
scales the quadrature outputs of the complex multiplier by
1/2 providing a gain of G = 0.5. If the Mixer is bypassed, the
signal is passed unmodified with a gain of 1.0. Following the
mixer, the quadrature signal is passed to the fixed coefficient
RRC filtering block, which has a gain of 1.13 if enabled and
1.0 if bypassed. Next, the AGC supplies gain to maintain an
optimal signal level at the input to the Soft Decision Slicer,
Cartesian-to-Polar Converter, and the Symbol Tracking
Loop. The gain supplied by the AGC ranges from 1.0 to
1.9844*2
3
.
Symbol Tracking
The symbol tracking loop adjusts the baseband sampling
frequency to force sampling of the baseband waveform at
optimal points for data decisions. The key elements of this loop
are the Sampling Error Detector and Symbol Tracking Loop
Filter shown in Figure 11. The output of these two blocks is a
frequency correction term which is used to adjust the baseband
sample frequency external to the HSP50210. In typical
applications, the frequency correction term is fed back to the
HSP50110 to adjust baseband sampling via the Resampling
NCO (see HSP501 10 Datasheet).
15
FN3652.5
July 2, 2008
REGISTER ENABLE RATE
www.BDTIC.com/Intersil
! = SYMBOL RATE
BLANK = CLK RATE
SYMBOL TRACK
LOOP FILTER
LEAD GAIN
16
FRZ_ST
MID AND END
SYMBOL SAMPLES
END
MID
!
END
MID
R
E
G
SAMPLING ERROR DETECTOR
I
I
Q
Q
DATA
DECISION
MID-SYMBOL
DATA
DECISION
MID-SYMBOL
TRANSITION
DETECT
TRANSITION
MID-POINT
TRANSITION
DETECT
TRANSITION
MID-POINT
LEAD
MANTISSA
‘0’‘-1’‘1’
MUX
ACQ
ZERO
LEAD
“0”
LEAD
MANTISSA
TRACK
REGREG
MUX
-
+
“0”
‘0’‘-1’‘1’
‘0’
MUX
SINGLE/
DOUBLE
RAIL
SAMPLING
MUX
-
+
+
MUX
ERROR
INVERT
INVERT
ERROR
!
ERROR
ACCUM.
“0”
ZERO
LAG
REGREG
LAG
MANTISSA
ACQ
MUXMUX
MUX
LAG
MANTISSA
TRACK
LEAD
EXPONENT
ACQ
REG
REGREG
LAG
EXPONENT
ACQ
MUX
SHIFTSHIFT
MUX
LEAD
EXPONENT
TRACK
REG
+
MUX
LOAD
ACC
LAG
EXPONENT
TRACK
REG
LIMIT
ACC LIMITS
UPPER/LOWER
LAG
ACCUMULATOR
+
SERIAL
OUTPUT
FORMATTER
SOFSYNC
REG
TO
μP
INTERFACE
SOF
HSP50210
July 2, 2008
FN3652.5
FIGURE 11. SYMBOL TRACKING
LAG GAIN
HSP50210
www.BDTIC.com/Intersil
Sampling Error Detector
The Sampling Error Detector is a decision based error
detector which determines sampling errors on both the I and
Q processing paths. The detector assumes that it is fed with
samples of the baseband waveform taken in the middle of
the symbol period (mid-symbol sample) and between
symbols (end-symbol sample) as shown in Figure 12. The
sampling error is a measure of how far the mid-symbol
sample is from the symbol transition mid-point. The
transition mid-point is half way between two symbol
decisions. The detector makes symbol decisions by
comparing the end-symbol samples against a selectable
threshold set (see Modulation Order Select bits 9 through 10
in Table 29 on page 37). The error term is generated by
subtracting the mid-symbol sample from the transition midpoint. The sign of the error term is negated for negatively
sloped symbol transitions. If no symbol transitions are
detected the error detector output is zeroed. Errors on both
the I and Q processing paths are summed and divided by
two if Double Rail error detection is selected (see Symbol
Tracking Configuration Control Register, Bit 8: Table 29 on
page 37).
The sampling Error Detector provides an error accumulator
to compensate for the processing rate of the loop filter. The
error detector generates outputs at the symbol rate, but the
loop filter can only accept inputs every eight f
Thus, if the symbol rate is faster than 1/8 CLK, the error
accumulator should be used to accumulate the error until the
loop filter is ready for a new input. If the error accumulator is
not used when the symbol rate exceeds 1/8 CLK, some error
outputs will be missed. For example, if f
error accumulation is required for symbol rates greater than
5 MSPS (f
be scaled accordingly if the accumulator is used.
/8). Note: The loop filter lead gain term must
CLK
MID-SYMBOL
SAMPLE
CLK
X
X
SAMPLING
ERROR
FIGURE 12. TRACKING ERROR ASSOCIATED WITH
BASEBAND SAMPLING ON EITHER I OR Q RAIL
(BPSK/QPSK)
X
X
TRANSITION
X
X
MIDPOINT
clocks.
CLK
= 40MHz, then
END-SYMBOL
SAMPLE
EXPECTED
SYMBOL
LEVELS
Symbol Tracking Loop Filter
The Symbol Tracking Loop Filter is a second order lead/lag
filter. The sampling error is weighted by th e lag gain and
accumulated to give the integral response (see Figure 11).
The Lag Accumulator output is summed with the sampling
error weighted by the Lead Gain. The result is a frequency
term which is output serially, via the SOF output, to the
NCO/VCO controlling the baseband sample rate (see “Serial
Output Interfaces” on page 23). In basic configurations, the
SOF output of the HSP50210 is connected to the SOF input of
the HSP501 10.
Two sets of registers are provided to store the loop gain
parameters associated with acquisition and tracking. The
appropriate loop gain parameters are selected manually via
the Microprocessor Interface or automatically via the Carrier
Lock Detector. The loop filter’s lead and lag gain terms are
represented as a mantissa and exponent. The mantissa is a
4-bit value which weights the loop filter input from 1.0 to
1.9375. The exponent defines a shift factor that provides
additional weighting from 2
mantissa and exponent provide a gain range between 2
and
~1.0 as given by Equation 10.
Lead/Lag Gain = (1.0+M*2-4)*2
where M = a 4-bit binary number from 0 to 15, and E is a 5-bit
binary value ranging from 0 to 31. For example, if M = 0101
and E = 001 10, the Gain = 1.3125*2
Control Registers described in Tables 32 and 33 beginning on
page 38.
A limiter is provided on the lag accumulator output to keep the
baseband sample rate within a user defined range (see
Tables 30 and 31 on page 38). If the lag accumulator exceeds
either the upper or lower limit, the accumulator is loaded with
the limit. For additional loop filter control, the loop filter output
can be frozen by asserting the FZ_ST pin which null the
sampling error term into the loop filter. The lag accu mulator
can be initialized to a particular value and can be rea d via the
microprocessor interface as described in “Reading from the
Microprocessor Interface” on page 27, and Table 34 on
page 39. The symbol tracking loop filter bit weighting is
identical to the carrier tracking loop bit weighting, shown in
Figures 9 and 10.
-1
-32
to 2
. Together the loop gain
-(32 -E)
-26
. They are stored in the
-32
(EQ. 10)
Soft Decision Slicer
The Soft Decision Slicer encodes the I/Q end-symbol
samples into 3-bit soft decisions. The input to the slicer is
assumed to be a bipolar (2ary) baseband signal
representing encoded values of either ‘1’ or ‘0’. The most
significant bit of the 3-bit soft decision represents a hard
decision with respect to the mid-point between the expected
symbol values. The 2 LSBs represent a level of confidence
in the decision. They are determined by comparing the
magnitude of the slicer input to multiples (1x, 2x, and 3x) of a
programmable soft decision threshold (see Figure 13).
17
FN3652.5
July 2, 2008
HSP50210
www.BDTIC.com/Intersil
HARD DECISION
THRESHOLD
‘1’ DECISION
STRONGERWEAKERSTRONGERWEAKER
-0.5
THRESHOLD
2x THRESHOLD
3x THRESHOLD
FS
1/2
MSB
1/3
0
1/3
MSB
1/2
-FS
FIGURE 13. OVERLAY OF THE HARD/SOFT DECISION
THRESHOLDS ON THE SYMBOL PROBABILITY
DENSITY FUNCTIONS (PDFs) FOR BPSK/QPSK
SIGNALS)
0.0
MSB-1
MSB-1
MSB-1
MSB-1
‘0’ DECISION
‘0’‘1’
0.5
THRESHOLD
2x THRESHOLD
3x THRESHOLD
PROBABILITY
DENSITY
FUNCTION
THRESHOLD
THRESHOLD
The soft decision threshold represents a range of
magnitude values from 0.0 to ~0.5. Note: Since the input to
the slicer has a range of 0.0 to
~1.0, the threshold setting
should be set to less than 1.0/3 = 0.33. This avoids
saturation. The slicer decisions are output in either a two’s
complement or sign/magnitude format (see Soft Decision
Slicer Configuration Control Register, Bit 7: Table 41 on
page 42). The slicer input to output mapping for a range of
input magnitudes is given in Table 7. For example, a
negative input to the slicer whose magnitude is greater
than twice the programmable threshold but less than 3x the
threshold would produce a sign/magnitude output of 110
(BINARY). The I and Q inputs to the slicer are encoded i nto
3-bit soft decisions ISOFT(2-0) and QSOFT(3-0). These
signals are routed to the OUTA(9-4) outputs by the Output
Configuration Control Register Selector bits 0-3 (see
Table 43 on page 44).
TABLE 7. SLICER INPUT TO OUTPUT MAPPING
SLICER INPUT MAGNITUDE
RELATIVE TO
SIGNAL
+>>>011011
+>>≤010010
+>≤<001001
+≤<<000000
-≤<<100111
->≤<101110
->>≤110101
->>>111100
INPUT POLARITY
1x
THRESHOLD2xTHRESHOLD
3x
THRESHOLD
SIGN/MAGNITUDE
OUTPUT
TWO’S
OUTPUT
COMPLEMENT
Carrier Phase Error Detector
The Carrier Phase Error is computed by removing the
phase modulation from the phase output of the
Cartesian-to-Polar Converter. To remove the modulation,
the phase term is rotated and multiplied (modulo 2π) to fold
the Phase Error into an arc centered about 0° but
encompasses the whole plane, as shown in Figure 14. The
phase rotation is performed by adding a 4-bit two’s
complement phase offset (resolution 22.5°) to the 4 MSBs
of the 8-bit phase term. The multiplication is performed by
left shifting the result from 0 to 3 positions with the MSBs
discarded and zeros inserted into the LSBs. For example,
Carrier Phase Error produces I/Q constellation points which
are rotated from the expected constellation points as
shown in Figure 14. By adding an offset of 45° (0010 0000
binary) and multiplying by 4 (left shift by two positions) the
phase modulation is removed, and the error is folded into a
90° arc centered at 0°. The left axis represents a decision
boundary of ±45°C, implying the vertical axis is ±22.5° as
shown in Figure 15. The phase offset and shift factors
required for different PSK orders is given in Table 9 on
page 21. Configuration of the Carrier Phase Error Detector
is done via the Carrier Phase Error Detector Control
Register, bit s 0 to 5, (see Table 18 on page 33). The Phase
Error term may be selected for output via the Output
Selector Configuration Control Register, bits 0 to 3 (see
Table 43 on page 44).
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In applications where Phase Error terms are generated
faster than the processing rate of the Carrier Loop Filter, an
error accumulator is provided to accumulate errors until the
loop filter is ready for a new input. Phase Error terms are
generated at the rate I/Q samples are input to the Cartesian
to Polar Converter. However, the Carrier Loop Filter cannot
accept new input faster than CLK/6 since six CLK(f
CLK
)
clock edges are required to complete its processing cycle. If
the error accumulator is not used and the I/Q sample rate
exceeds CLK/6, error terms will be missed.
Note: The carrier Phase Error terms input to the loop filter
are only generated from the end-symbol samples when the
output of the I and D filter is selected for input to the
Cartesian-to-Polar converter.
Note: The loop filter lead gain term must be scaled
accordingly if the accumulator is used.
The Carrier Loop Filter is second order lead/lag filter as
shown in Figure 14. The loop filter is similar to the Symbol
Tracking Loop Filter except for the additional terms from the
AFC Loop Filter and the Frequency Sweep Block. The
output of the Lag Accumulator is summed with the weighted
Phase Error term on the lead path to produce a frequency
control term. The Carrier Loop Filter is configured for
operation by the Control Registers described in Tables 21
through 28 beginning on page 34.
The Carrier Tracking Loop is closed by using the loop filter
output to control the NCO or VCO used to down convert the
channel of interest. In basic configurations, the frequency
correction term controls the Synthesizer NCO in the
HSP50110 Digital Quadrature Tuner via the COF and
COFSYNC pins of the HSP50210’s serial interface (see
“Serial Output Interfaces” on page 23). In applications where
the carrier tracking is performed using the NCO on board the
HSP50210, the loop filter output is fed to the on-board NCO
as a frequency control.
The gain for the lead and lag paths of the Carrier Loop Filter
are set through a programmable mantissa and exponent.
The mantissa is a 4-bit value which weights the loop filter
input from 1.0 to 1.9375. The exponent defines a shift factor
-1
that provides additional weighting from 2
to 2
-32
. Together
the loop gain mantissa and exponent provide a gain range
between 2
Lead/Lag Gain = (1.0+M*2-4)*2
-32
and ~1.0 as given by Equation 11.
-(32 -E)
(EQ. 11)
where M = a 4-bit binary number from 0 to 15, and E is
a 5-bit binary value ranging from 0 to 31. For example, if
M = 0101 and E = 00110, the Gain = 1.3125*2
-26
. The loop
gain mantissa and exponent are set in the Carrier Loop Gain
Control Registers (see T ables 25 through 26 on page 36).
The Phase Error input to the Carrier Loop Filter is an 8-bit
fractional two’s complement number between ~1.0 to -1.0
(Format -2
0
. 2-12-22-32-42-52-62-7). Some LSBs are zero for
BPSK, QPSK and 8-PSK. If minimum loop gain is used, the
Phase Error is shifted in significance by 2
-32
. With maximum
loop gain, the Phase Error is passed almost unattenuated.
The output of the Carrier Loop filter is a 40-bit fractional
two’s complement number between ~1.0 and -1.0 (Format -
0
2
. 2-12-22-3..... 2
-392-40
). In typical applications, the 32
MSBs of the loop filter output represent the frequency
control word needed to adjust the down converting NCO for
phase lock. Tables 9 and 10 beginning on page 21 illustrate
the bit weighting of the Carrier Loop Filter into the NCO for
both tracking and acquisition sweep modes.
A limiter is provided on the Carrier lag accumulator output to
keep frequency tracking within a user defined range (see
Tables 23 and 24 on page 35). If the lag accumulator
exceeds either the upper or lower limit the accumulator is
loaded with the limit. For additional loop filter control, the
Carrier Loop Filter output can be frozen by asserting the
FZ_CT pin which nulls the Phase Error term into the loop
filter. Also, the lag accumulator can be initialized to a
particular value via the Microprocessor Interface as
described in Tab le 28 on page 37 and can be read via the
microprocessor interface as described in “Reading from t he
Microprocessor Interface” on page 27.
The Frequency Sweep Block is used during carrier acquisition
to sweep the range of carrier uncertainty. The Sweep Block is
loaded with a programmable value which is input to the lag path
of the Carrier Tracking Loop Filter when frequency sweep is
enabled. The sweep value is accumulated by the loop filter’s
lag accumulator which causes a frequency sweep between the
accumulator’s upper and lower limits. When one of the limits is
reached, the sweep value is inverted to sweep the frequency
back toward the other limit. The Frequency Sweep Block is
controlled by the Lock Detector and is only enabled during
carrier acquisition (see “Lock Detector Control” on page 24).
A stepped acquisition mode is provided for microprocessor
controlled acquisition. In the stepped acquisition mode, the lag
accumulator is incremented or decremented by the
programmed sweep value each time the lock detector is
restarted during acquisition. This technique prevents the loop
from sweeping past the lock point before the microprocessor
can respond. Typically in stepped acquisition mode, the step
value is set to a percentage of the loop bandwidth. A dwell
counter is also provided for stepped acquisition. This counter
holds off the lock detector integration from 1 to 129 symbols to
allow the loop to settle before starting the integration.
The sweep value is set via a programmable mantissa and
exponent. The format is 01.MMMM * 2
MMMM is the 4-bit mantissa and EEEEE is the 5-bit exponent
and the weighting is relative to the MSB of the NCO control
word. In swept acquisition mode, the sweep value is the
amount that the carrier lag accumulator is incremented or
decremented each time a new filter output is calculated (sweep
rate/N). In stepped acquisition mode, it is the amount the lag
accumulator is incremented or decremented each time that the
lock detector is restarted. (See Frequency Sweep/AFC Control
Loop Control Register, Table 27.)
-(28 - EEEEE)
where
Error Detector. For PSK demodula tion, this block is byp assed
by setting the offset and shift terms to zero (see Frequency
Error Detector Control Register; Table 20 on page 34). The
frequency error term may be selected for output via the Output
Select Block. (See Serial Output Configuration Control
Register, Table 42 on page 42).
Automatic Frequency Control (AFC)
Loop Filter
The AFC Loop Filter supplies a frequency correction term to
the lag path of the Carrier Loop filter . The frequency correction
term is generated by weighting the output of the Frequency
Error Detector by a user programmable weight (see
Sweep/AFC Control Register; Table 27 ). Note: If AFC is n ot
desired, the frequency error term to the loop filter is nulled via
the Carrier Tracking Configuration Control Register #2 (see
Table 22 on page 35).
Serial Output Interfaces
Frequency control data for Carrier and Symbol Tracking is
output from the DCL through two separate serial interfaces.
The Carrier Offset frequency control is output via the COF
and COFSYNC pins. The Symbol Tracking Offset frequency
control is output via the SOF and SOFSYNC pins. A
SLOCLK is provided to allow for reduced serial rate data
exchanges. The timing relationship of these signals is shown
in Figure 16.
CLK
COFSYNC/
SOFSYNC
COF/SOF
Note: Data must be loaded MSB first.
MSB
LSB
MSB
Carrier Frequency Detector
The Frequency Detector generates a frequency term for use
in Automatic Frequency Control (AFC) configurations. The
Frequency Detector (discriminator) subtracts a previous
Phase Error sample from the current one (d/dt) to produce a
term proportional to the carrier frequency. The discriminator
gain is adjusted by programming a variable delay (1-16)
between the samples subtracted (see Frequency Detector
Control Register; Table19).
Note: The input to the discriminator corresponds to phase
terms taken from baseband samples at either the SYNC rate or
twice symbol rate depending on the input source chosen for the
Cartesian-to-Polar converter.
Carrier Frequency Error Detector
The Frequency Error Detector is used to generate a frequency
error term for FSK modulated waveforms. The error is
computed by adding an offset and shifting the frequency
detector output in a manner similar to that used by the Phase
23
FIGURE 16. SERIAL OUTPUT TIMING FOR COF AND SOF
OUTPUTS
Each serial word has a programmable word width of either 8,
12, 16, 20, 24, 28, 32, or 40 bits (see Table 42, CW27, bits 4
through 6 for COF and bits 0 through 2 for SOF). The
polarity of the sync signals is programmable and is set in
CW27 Bit 12 for SOF and Bit 11 for COF. The polarity of the
serial clock to the serial data is programmed via CW27
Bit 10. If reduced rate frequency updates is required, the
SLOCLK rate is selected via CW27 Bit 7 and the rate is set
via CW27 bits 8 through 9, to be either CLK/2, CLK/4, CLK/8
or CLK/16. Note that if the DCL is used with the HSP50110
DQT, then the SLOCLK cannot be used, i.e., the serial clock
must be set to be CLK.
Lock Detector
The Lock Detector consists of the Dwell Counter, Integration
Counter, Phase Error Accumulator, False Lock/Frequency
Accumulator, Gain Error Accumulator and the Lock Detect
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State Machine (see Figure 16). The function of the Lock
Detector is to monitor the baseband symbols and to decide
whether the Carrier Tracking Loop is locked to the input
signal. Note: The Symbol Tracking Loop locks
independently; under most circumstances, it will lock before
the Carrier Tracking Loop locks up. Based on the
in-lock/out-of-lock decision, either the Acquisition or Tracking
parameters are selected in the Carrier Tracking Loop, the
Symbol Tracking Loop and in the Lock Detector itself. The
Lock Detector can be configured either to make the “lock”
decision automatically using the State Machine Control
Mode, or to collect the necessary data so that an external
microprocessor can control the acqui s iti on /tracking process
via the Microprocessor Control Mode (see Figure 22).
In State Machine Control Mode, the Lock Detector State
Machine monitors the outputs of the Phase Error Accumulator
and the False Lock Accumulator to determine the Lock
Detector state. Accumulation effectively averages the Phase
Error and false lock count, reducing their variance. Lock is
detected by accumulating the magnitude of the Phase Error
over a predetermined interval up to 1025 symbols (the
Integration Time). When the Carrier Loop is locked, the
Integration Period will end before an overflow occurs in the
Phase Error Accumulator. At the beginning of a lock detection
cycle, the Phase Error Accumulator and the Integration Counter
are loaded with their respective pre-load values. With each end
bit sample, the Phase Error Accumulator adds the magnitude of
the current Phase Error to its accumulated sum, while the
Integration Counter decrements one count. The Lock Detector
State Machine monitors the overflow bit of the Phase Error
Accumulator and the output of the Integration Counter . If the
Phase Error Accumulator overflows before the Integration
Counter reaches zero, then the accumulated Phase Error is too
large for the Carrier Tracking Loop to be in lock and the Lock
Detector State Machine goes into the Search state (see Lock
Detector State Machine in Figure 17). In the search state, the
loop parameters are reloaded with “Acquisition” rather than
“Tracking” values. When the Phase Accumulator overflows or
when the Integration Counter reaches zero, the Integration
Counter and the accumulators are re-initialized and the process
begins again. The Integration Counter Pre-load corresponds to
the number of symbols over which to integrate. The Phase
Error Preload corresponds to the distance the Phase Error
Accumulator starts away from overflow. This dist ance divided
by the Integration Period equals the average Phase Error. The
pre-load value is calculated using Equation 12:
Preload =
Full Scale
where
Full scale = 2
Full scale phase = 180° for CW, 90° for BPSK, 45° for QPSK,
etc;
Lock Threshold
⎛⎞
----------------------------------------------
–
⎝⎠
Full Scale Phase
18
-1
x 128 x Integration Count
(EQ. 12)
Lock Threshold <45° for BPSK, <22.5° for QPSK, etc.
(typical after shift); and Integration Count = Integration
Period measured in symbol times.
The False Lock Detector is used to indicate false lock on
square wave data in a high SNR environment. A false lock
condition is detected by monitoring the final integration stage
in the Q branch of the Integrate and Dump Filter (see
Figure 3 on page 7). If the magnitude of the integration over
the symbol period is less than the integration over half a
symbol period, a possible false lock condition is detected;
(integration over a symbol period has gone from end-bit to
end-bit, while integration over half the symbol period has
gone from the previous end-bit to mid-bit). By accumulating
the number of these occurrences over the Integration
Period, the Lock Detector State Machine determines
whether a false lock condition exists. The False Lock
Accumulator is used to accumulate the number of possible
false lock occurrences over the Integration Period. The
False Lock Accumulator can also be configured to
accumulate the output of the Frequency Error Detector (see
Lock Detection Configuration Control Register Bit 27:
Table 35 on page 40).
The Gain Error Accumulator provides a mechanism to
estimate data quality (E
the magnitude of the gain error of the end-bit samples, over
the Integration Period. Note: The Gain Error end-bit data is
valid only after lock has been declared, and the demod is
the tracking mode. The accumulated value gives an
indication of the variance about the ideal constellation
points. The accumulator output is read via the
Microprocessor Interface. The Gain E rror Acc umu lator is
always pre-loaded with zero.
For applications where stepped acquisition is used, a Dwell
Counter is provided. In this mode, the lag accumulator in the
Carrier Loop Filter is stepped to a new frequency after each
Lock Detector integration. The Dwell Counter is used to hold
off Lock Accumulator integration until the loop has a chance
to settle.
). The accumulator integrates
s/No
Lock Detector Control
The selection of acquisition and tracking modes is controlled
by either the internal state machine or an external
microprocessor. The internal state machine monitors the
rollover of the Phase Error Accumulator and the False Lock
Accumulator relative to the Integration Counter. Depending
on whether the accumulators or counter roll over first, the
acquisition or tracking parameters are selected for the Loop
Filters and the Lock Detector Accumulators. In addition, the
state machine controls the frequency sweep input to the
Carrier Tracking Loop.
The flow of the acquisition control is shown in the State
Diagram in Figure 18 on page 26. The state machine
controls the acquisition process described as follows:
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Search. The frequency uncertainty is swept by enabling the
Frequency Sweep Block to the lag path of the Carrier
Tracking Loop Filter. The acquisition parameters are
enabled to the Loop Filters and the Lock Detector
Accumulators. Phase lock is obtained when the Lock
Counter rolls over before the Phase Error Accumulator
(average Phase Error is less than the lock threshold).
Verify. Once phase lock is obtained, the frequency sweep is
disabled and the tracking parameters are enabled. Lock is
verified if the accumulated Phase Error is below the
threshold for a programmable number of Integration Periods.
False lock conditions are also monitored by comparing the
roll over of the False Lock Accumulator to that of the
Integration Counter. If the False Lock Accumulator rolls over
before the Integration Counter, a false lock condition exists.
False Lock. Once a false lock has been determined, the
Frequency Sweep block is enabled to move the carrier
tracking beyond the false lock region. The Frequency Sweep
is performed for a programmable number of Integration
Periods before returning to the search state.
Lock. When phase lock has been verified, the Lock status
output is asserted and the False Lock Detector is disabled.
The lock state is maintained as long as the Integration
Counter rolls over before the Phase Error Accumulator.
If the acquisition and tracking process is controlled externally,
the Phase Error Accumulator and False Lock Accumulators
are monitored by an external processor to determine when
lock has been achieved. In this mode the accumulator
pre-loads are typically set to zero and the accumulator output
is compared in the processor against a threshold equal to th e
maximum Phase Error per sample times the number of
samples per Integration Period. The accumulators stop after
each Integration Period to hold their outputs for reading via
the Microprocessor Interface (see Read Enable Address Map;
Table 13 on page 28). The accumulators are restarted by
writing the Initialize Lock Detector Control address (see
Initialize Lock Detector Control Register: Table 45 on
page 46). To simplify the processor interface, the LKIN T
output is provided to interrupt the processor when the
accumulator integration period is complete. The processor
controls the use of the acquisition/tracking parameters and
lock status line by setting the appropriate bits in the
Acquisition/Tracking Configuration Control Register (see
Table 38 on page 41). In addition, the frequency sweep
function is enabled via the Microprocessor Interface.
DWELL
COUNT
ACQ
COUNTER
“0”
TRACK
DWELL
TCSTARTTC
SWEPT
INT
PERIOD
ACQ
MUXMUX
INTEGRATION
COUNTER
INT
PERIOD
TRACK
PHASE
ERROR
PRELOAD
ACQ
PHASE
ERROR
PRELOAD
TRACK
MUX
MUX
LOCK DETECTOR STATE MACHINE
PRELOAD
PHASE
ERROR
|X|
+
REG
OVERFLOWOVERFLOW
ACQUIRE/
TRACK
FALSE
LOCK
ACQ
FALSE
LOCK
PRELOAD
TRACK
MUX
FALSE LOCK/
FREQUENCY
ERROR
“0”
|X|
+
MUX
REGREG
MUX
GAIN
ERROR
|X|
+
FIGURE 17. LOCK DETECTOR BLOCK DIAGRAM
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ACCUMULATOR
FINISHES BEFORE
INTEGRATION COUNTER
INTEGRATION
COUNTER FINISHES
BEFORE
PHASE ERROR
ACCUMULATOR
LOCK COUNTER
FALSE
DONE
HSP50210
PHASE ERROR ACCUMULATOR
FINISHES BEFORE
INTEGRATION COUNTER
SEARCH
PHASE ERROR
ACCUMULATOR
FINISHES BEFORE
INTEGRATION
COUNTER
INTEGRATION
COUNTER
FINISHES BEFORE
PHASE ERROR
ACCUMULATOR
AND VERIFY
COUNTER DONE
FALSE LOCK
ACCUMULATOR
BEFORE
LOCK COUNTER
FALSE
LOCK
INTEGRATION COUNTER
FINISHES BEFORE
PHASE ERROR ACCUMULATOR
VERIFYLOCK
FALSE
LOCK COUNTER
NOT DONE
INTEGRATION COUNTER
FINISHES BEFORE
PHASE ERROR
ACCUMULATOR AND
VERIFY COUNTER
NOT DONE
FIGURE 18. ACQUISITION/TRACKING STATE DIAGRAM
Serial Output Controller
The frequency correction terms generated by the Symbol
and Carrier Loop Filters are output through two separate
serial interfaces. The symbol frequency offset used to close
the symbol Tracking Loop is output via the SOF and
SOFSYNC outputs. The carrier offset frequency used to
close the Carrier Tracking Loop is output via the COF and
COFSYNC outputs.
The serial output timing, identical for both of the loop filter
outputs, is shown in Figure 19. The data word is output MSB
first starting with the first rising edge of either CLK or
SLOCLK that follows the assertion of sync (COFSYNC or
SOFSYNC). The HSP50210 is configured to output the
serial data with either CLK or SLOCLK (see Serial Output
Configuration Control Registers Bit 7, Table 42 on page 42).
The SLOCLK output is a programmable sub-multiple of CLK
which is provided for applications requiring a slower serial
clock. In applications where the HSP50210 is used with the
HSP50110, both parts must be supplied with the same CLK
and the HSP50210 is configured to use CLK as the serial
clock. The serial output can be configured for word
containing from 8 to 40 bits.
CLK/
SLOCLK
COFSYNC/
SOFSYNC
COF/
SOF
MSBMSB
Note: COFSYNC and SOFSYNC shown Configured as
active “High”.
FIGURE 19. SERIAL OUTPUT TIMING FOR COF AND SOF
OUTPUTS
Output Selector
The output selector determines which internal signals are
multiplexed to the AOUT9-0 and BOUT9-0 outputs. Fifteen
different output options are provided: ISOFT(2:0), QSOFT(2:0),
IEND(7:1), QEND(7:1), AGC(7:1), MAG(7:0), Phase(7:0),
FREQERR(7:1), GAINERR(7:1), BITPHERR(7:1),
CARPHERR(7:1), LKACC(6:0), LKCNT(6:0), NCOCOS(9:0),
and STATUS (6:0). These are detailed in the Output Selector
Configuration Control Register, bits 0 through3 (see Table 43
on page 44).
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The status bit definition is shown in Table 11:
TABLE 11. STATUS BIT DEFINITIONS
STATUS BITDEFINITION
6Carrier Tracking Loop Lock
5Acq/Trk
4Frequency Sweep Direction
3High Power
2Low Power
1Data Rdy
To simplify the output interface, a symbol clock (SMBLCLK)
is output which is synchronous to the soft bit decisions
produced by the Slicer. The SMBLCLK is a 50% duty cycle
clock whose rising edge is centered in the middle of the
output data period for both the soft bit decisions and the
end-symbol samples, as shown in Figure 20.
SMBLCLK
ISOFT2-0/
QSOFT2-0/
IEND7-1/
QEND7-1
FIGURE 20. OUTPUT DATA CLOCK TIMING
Microprocessor Interface
The Microprocessor Interface is used to write the
HSP50210’s Control Registers and monitor various read
points within the demodulator. Dat a written to the interface is
loaded into a set of four 8-bit holding registers, on e Write
Address Register, or one Read Address Register. These
registers are accessed via the 3-bit address bus (A0-2) and
an 8-bit data bus (C0-7) as shown in Table 12. The R/W
column indicates whether the data is read from or written to
the given address.
TABLE 12. READ/WRITE ADDRESS MAP FOR
MICROPROCESSOR INTERFACE
R/W A2-0DESCRIPTION
W000 Input Holding Register 0. Transfers to bits 7-0 of the
target control register. Bit 0 is the LSB of the target
register.
W001 Input Holding Register 1. Transfers to bits 15-8 of the
target control register.
W010 Input Holding Register 2. Transfers to bits 23-16 of a
32-bit target control register.
W011 Input Holding Register 3. Transfers to bits 31-24 of the
target control register. Bit 31 is the MSB of the 32-bit
register.
W100 Write Address Register. The register is loaded with the
address of the control register targeted for update. The
address map for the control registers is given in
Tables 1C-32C.
Note: Addresses outside the range 0-31 are invalid.
TABLE 12. READ/WRITE ADDRESS MAP FOR
R/W A2-0DESCRIPTION
W101 Read Address Register. The address loaded into this
R000 Selects output holding register bits 7-0 for output on
R001 Selects output holding register bits 15-8 for output on
R010 Selects output holding register bits 23-16 for output on
R011 Selects output holding register bits 31-24 for output on
R100 Multiplexes 8 bits of internal status out on C7-0. See
MICROPROCESSOR INTERFACE (Continued)
register specifies an internal read point as given the by
address map in Table 12. Addresses outside the range
0-4 are invalid.
C7-0 respectively. Bit 0 is the LSB of the internal holding
register.
C7-0, respectively.
C7-0, respectively.
C7-0, respectively. Bit 31 is the MSB.
Table 14 for bit map.
Data is read from an Internal Status Register and a series of
output holding registers. The output holding registers range
in size from 8 to 32 bits, and their contents are multiplexed
out a byte at a time on C7-0 by controlling A2-0 and
asserting RD
. The addresses listed in Table 11 with the R
indicator provide the address map used for reading data
from the Microprocessor Interface.
Writing to the Microprocessor Interface
The HSP50210 is configured for operation by loading a set
of thirty-two control registers which range in size from 0 to
32 bits. They are loaded by first writing the configuration
data to the Microprocessor interface’s four holding regi sters
and then writing the target address to the Write Address
Register as shown in Figure 21. The Control Register
Address Map and bit definitions are given in Tables 14
through 45. The configuration data is transferred from the
holding registers to the target control register on the fourth
clock following a write to the address register. As a result,
the holding registers should not be updated any sooner
than 4 CLKs after an address register write (see Figure 21).
Note: The holding registers which map to the unused bits of
a particular control register do not have to be loaded.
Reading from the Microprocessor Interface
The Microprocessor Interface is used to monitor
demodulator operation by providing the ability to read the
accumulator contents in the Lock Detector and Loop
Filters. In addition, the interface is used to monitor the
HSP50210’s Internal Status Register. More clearly, the
following data is available to be read:
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#
REGISTERSDEFINITION
(4)32-bit Carrier Loop Letter Lag Acc. Output
(4)32-bit Symbol T racking Loop Letter Lag Acc. Output
(1)8-bit AGC Loop Letter Output
(2)16-bit Lock Detector φe Acc. Output
(2)16-bit Lock Detector GE Acc. Output
(2)16-bit Lock Detector FL/FE Acc. Output
(1)8-bit Internal Status
Total = 16
A different read procedure is required depending on
whether the Lock Detector Accumulators, loop filter
accumulators, or the Status Register is to be read. The
read procedures are summarized in Figures 21 through 23.
The accumulators in the AGC Loop Filter, Carrier Loop
Filter and Symbol Tracking Loop can be read via the
Microprocessor Interface. Since these accumulator s are
free running, their contents must be loaded into output
holding registers before they can be read. Each
accumulator has its own output holding register. The three
holding registers are updated by loading 29 (decimal) into
the Write Address Register of the Microprocessor Interface.
The output of a particular holding register is then enabled
for reading by loading its address into the Read Address
Register (see Tables 12 and 13). The holding register
addresses for the loop filter accumulators range from 0 to 4
as given in Table 13. The contents of the output holding
registers are multiplexed out a byte at a time on C7-0 by
changing A2-0 and asserting RD (see Read/Write Address
Map in Table 12).
TABLE 13. READ ENABLE ADDRESS MAP
ADDRESSHOLDING REGISTER ENABLE
0Carrier Loop Filter Lag Accumulator. Enables output
of holding register containing 32 MSBs of the lag
accumulator.
1Symbol Tracking Loop Filter Lag Accumulator.
Enables output of holding register containing 32
MSBs of the lag accumulator.
2AGC GAIN. Enables output of holding register
containing 8 MSBs of the AGC accumulator.
3Lock Detector 1. The 16 MSBs of the Lock Detector’s
Phase Error Accumulator and the 16 MSBs of the
False Lock Accumulator are enabled for output. The
accumulator contents are selected for output as
follows, A2-0 = 3 (decimal) selects MSByte of the
Phase Error Accumulator, A2-0 = 2 (decimal) selects
LSByte of the Phase Error Accumulator, A2-0 = 1
(decimal) selects MSByte of the False Lock
Accumulator, and A2-0 = 0 (decimal) selects LSByte
of the False Lock Accumulator.
4Lock Detector 2. Enables th e 16 MSBs of the Lock
Detector’s Gain Error Accumulator for output. The
MSByte of the accumulator is selected for output by
setting A2-0 = 1, and the LSByte is selected by A2-0
= 0.
The contents of the three accumulators in the Lock Detector
can also be read via the Microprocessor Interface. However,
the Lock Detector must be stopped before a read can be
performed. In State Machine Control Mode, the Lock
Detector is stopped by loading 24 (decimal) into the Write
Address Register. In Microprocessor Control Mode, the Lock
Detector stops after each Integration Period. To determine
when the Lock Detector has stopped and is ready for
reading, bits 7 and 6 of the Internal Status Register (SR7
and 6) must be monitored (see Table 14 on page 30). The
control sequence for reading a Lock Detector Accumulator is
shown in Figure 23. The control sequence for reading a Lock
Detector Accumulator using the LKINT signal is shown in
Figure 24.
An 8-bit Internal Status Register (SR7-0) can also be
monitored via the Microprocessor interface. The Status
Register indicates loop filter and Lock Detector status as
listed in Table 14 on page 30. The St atus Registe r content s
are output on C7-0 by setting A2-0 to 100 (binary) an
asserting RD as shown in Figure 25 on page 31. The
register contents are updated each CLK.
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WR
RD
DON’T CARE
A0-2
SIGNALS
PROCESSOR
C0-7
CLK
EARLIEST TIME ANOTHER
NOTE: These processor signals are meant to be representative. The actual shape of the waveforms will be set by the microprocessor used. Verify
that the processor waveforms meet the parameters in “Waveforms” on page 50 to ensure proper operation. The Processor waveforms are not
required to be synchronous to CLK. They are shown that way to clarify the illustration.
FIGURE 21. CONTROL REGISTER LOADING SEQUENCE
WR
RD
DON’T CARE
PROCESSOR
SIGNALS
A0-2
C0-7
CLK
1234
56
315402
MSBLSB029
4321001
1234
LOAD CAN BEGIN
ADDRESS IS ASYNCHRONOUS TO CLK
DATA IS
ASYNCHRONOUS
TO CLK
123 45
LOAD OUTPUT
HOLDING REG
ENABLE
HOLDING
REG
FOR
READ
WAIT
6 CLKs
DELAY
TO
RD
ASSERT
READREADREADREAD
NOTE: These processor signals are meant to be representative. The actual shape of the waveforms will be set by the microprocessor used. Verify
that the processor waveforms meet the parameters in “Waveforms” on page 50 to ensure proper operation. The Processor waveforms are not
required to be synchronous to CLK. They are shown that way to clarify the illustration.
1. Load the Write Address Register with 29
to load the output holding registers.
dec
2. Enable Carrier Loop Filter Lag Accumulator holding register for reading.
3. Select the MSByte of the output holding register for output.
4. Assert RD
5. Select other bytes of holding register by changing A0-2 and asserting RD
low to output data on C0-7. (Must wait for 6 CLKs after loading the holding registers).
.
FIGURE 22. LOOP FILTER ACCUMULATOR READ SEQUENCE
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WR
RD
A0-2
SIGNALS
PROCESSOR
C0-7
CLK
DCL
SR-7
SIGNALS
3
SR7=0
1235686868
HALT LD
AT END OF
CYCLE
ENABLE
LD REG.
FOR READING
425413
SR7=1
STATUS READS
74
PE
MSW
86
LOCK DETECTION STATUS READSINTERNAL
PE
LSW
FL
MSW
NOTE: These processor signals are meant to be representative. The actual shape of the waveforms will be set by the microprocessor used. Verify
that the processor waveforms meet the parameters in “Waveforms” on page 50 to ensure proper operation. The Processor waveforms are not
required to be synchronous to CLK. They are shown that way to clarify the illustration.
1. Load the Write Address Register with 24
counter in the lock detector. The verify counter is not reset and will resume at the stopped value when the lock detector is restarted.
2. Load the Read Address Register with 3
to halt the Lock Detector after the current integration cycle. This disables the reload of the integration
dec
to enable the Lock Detector Phase Error Accumulator for reading.
dec
3. Read Internal Status Register to monitor SR-7 to determine when the Lock Detector is stopped and ready to be read.
4. SR-7 goes high, indicating the Lock Detector integration cycle is complete, and ready to be read.
5. Read Internal Status Register and find SR-7 = 1; the Lock Detector is ready to be read.
6. Change Read address to (3; 2; 1; 0) for (Phase Error MSW; PE LSW; False Lock MSW; FL LSW) read.
7. End of Internal Status Valid Data.
8. Assert RD
9. Load The Write Address Register with 30
machine mode).
10. Load the Write Address Register with 25
to Read Lock Detector Status
to initialize Lock Detector Accumulators and Reset the Integration counters. (Not needed for state
TABLE 14. INTERNAL STATUS REGISTER (SR7-0) BIT MAP
BITBIT DESCRIPTION
7Lock Detector Stopped and Ready for Reading
(State Machine Control Mode).
0 = Lock Detector not stopped.
1 = Lock Detector stopped, ready for read.
6Lock Detector Stopped and Ready for Reading
(Microprocessor Control Mode).
0 = Lock Detector not stopped.
1 = Lock Detector stopped, ready for read.
5Carrier Loop Filter Lag Accumulator Load Complete. This bit
is used to determine when a 32-bit load of Carrier Lag
Accumulator is complete. The accumulator load is initialized
by loading the Write Address Register with 13 (decimal) as
described in Table 28.
0 = Load not complete.
1 = Load complete.
4Symbol Tracking Loop Filter Lag Accumulator Load
Complete. This bit is used to determine when a 32-bit load of
Symbol Track Lag Accumulator is complete. The
accumulator load is initialized by loading the Write Address
Register with 19 (decimal) as described in Table 34.
0 = Load not complete.
1 = Load complete.
BITBIT DESCRIPTION (Continued)
3Lock. Carrier Lock state achieved by Lock Detector.
0 = Not locked.
1 = Locked.
2Acquisition/Track. Indicates whether the Lock Detector is in
acquisition or tracking mode.
0 = Tracking Mode.
1 = Acquisition Mode.
1Reserved.
0Frequency Sweep Direction, defined for upper sideband
signals.
0 = UP.
1 = DOWN.
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RD
HSP50210
A0-2
SIGNALS
PROCESSOR
C0-7
CLK
SR-7
DCL
SIGNALS
LKINT
12
NOTE: These processor signals are meant to be representative. The actual shape of the waveforms will be set by the microprocessor used. Verify
that the processor waveforms meet the parameters in “Waveforms” on page 50 to ensure proper operation. The Processor waveforms are not
required to be synchronous to CLK. They are shown that way to clarify the illustration.
3
345656578910
PE
MSW
203541
PE
LSW
FL
MSW
56
FL
LSW
4
30
25
1. LKINT Asserts Indicating End of Lock Detector Accumulation Cycle; Accumulators Ready to Read.
2. Set A0-2 to 5 for Reading Lock Detector.
3. Load Read Address Register with 3
to enable the Lock Detector Phase Error Accumulator for Reading.
dec
4. Set A0-2 to 3 for Phase Error (PE) Read.
5. Assert RD
and read (Phase Error (PE) MSW; PE LSW; False Lock (FL) MSW; FL LSW).
6. Change Read Address to (2; 1; 0) to read various Lock Detection values.
7. Change Address to 4 to Initialize the Lock Detector.
8. Load Write Address Register with 30
to initialize the Lock Detector Accumulators and Reset Integration Counters. (Only has
dec
an effect in µP mode).
9. Keep Address to 4 to Restart the Lock Detector.
to restart the Lock Detector. (Only necessary if not in the µP mode).
dec
.
CLK
RD
A0-2
C7-0
STATUS CAN CHANGE EVERY CLK
FIGURE 25. INTERNAL STATUS REGISTER READ
31
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TABLE 15. DATA PATH CONFIGURATION CONTROL REGISTER
DESTINATION ADDRESS = 0
BIT
POSITIONFUNCTIONDESCRIPTION
31-27ReservedReserved. Set to 0 for proper operation.
26-24Integrate/Dump Shifter
Gain
23-16Input Level Detector
Threshold
15Input Data Format Select 0 = Two’s Complement Input.
14Serial/Parallel Input
Select
13Input Level Detector
Output Select
12Q Input to Complex
Multiplier
11I Input to Complex
Multiplier
10Complex Multiplier
Bypass
9Demodulation/Loop
Filter Mode
Select
8Cartesian/Polar Input
Select
7RRC Filter Enable0 = Enable RRC filter.
6Integrate and Dump
Filter Test Mode
5Integrate and Dump
Input Select
4-1Integrate and Dump
Decimation Select
0OQPSK Data
De-Skew Select
These bits set the shifter attenuation in the Integrate/Dump Filter.
000 = No Shift (Gain = 2
001 = Right Shift 1 (Gain = 2
010 = Right Shift 2 (Gain = 2
011 = Right Shift 3 (Gain = 2
100 = Right Shift 4 (Gain = 2
Other Codes are invalid.
This register sets the magnitude threshold for the Input Level Detector (see “Input Level Detector” on
page 6). This 8-bit value is a fractional unsigned number whose format is given by:
0
. 2-1 2-2 2-3 2-4 2-5 2-6 2-7.
2
The possible threshold values range from 0 to 1.9961 (00 - FF hex). The magnitude range for complex
inputs is 0.0 to 1.4142 while that for real inputs range is 0.0 to 1.0. Note: The algorithm used to estimate
threshold produces a maximum output of 1.375, therefore a threshold of greater than 1.375 will never
be exceeded.
1 = Offset binary Input.
0 = Parallel Input.
1 = Serial Input.
0 = HI/LO output of 1 means input ≤ threshold.
1 = HI/LO output of 1 means input > threshold.
0 = QIN9-0 enabled to Complex Multiplier.
1 = Q input to Complex Multiplier zeroed.
0 = IIN9-0 enabled to Complex Multiplier.
1 = I input to complex multiplier set to negative full scale (200 Hex).
0 = Data enabled to Complex Multiplier (Multiplied by output of NCO).
1 = Complex Multiplier Bypassed.
0 = Error detector outputs routed to Loop Filters (Normal Mode of Operation).
1 = Part functions as dual Loop Filters. The IIN9-0 input is routed to the Symbol Loop Filter; the
QIN9-0 input is routed to the Carrier Loop Filter. Data is gated into the Loop Filters with the assertion
of SYNC
0 = Enable output of AGC Multiplier to Cartesian to Polar Converter.
1 = Enable output of Integrate and Dump Filter to the Cartesian to Polar Converter.
1 = Both End and Mid Symbol routed to Output Formatter: End-symbol samples occur when
0 = Input taken from output of Frequency Discriminator (FSK routing).
1 = Input taken from output of AGC Multiplier (Select this setting for PSK demodulation).
Bit 4 is the MSB.
1000 = No Decimation (no accumulation, no sample pair summing).
0000 = Decimation by 2 (no accumulation, sample pair summing).
0001 = Decimation by 4 (accumulate 2 samples, sample pair summing).
0010 = Decimation by 8 (accumulate 4 samples, sample pair summing).
0011 = Decimation by 16 (accumulate 8 samples, sample pair summing).
0100 = Decimation by 32 (accumulate 16 samples, sample pair summing).
All other codes are invalid.
0 = Disables Q channel data delay.
1 = Delays Q Channel by 1/2 Symbol time to remove OQPSK stagger.
.
SMBLCLK is high; Mid-Symbol samples occur when SMBLCLK is low.
0
).
-1
).
-2
).
-3
).
-4
).
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TABLE 16. POWER DETECT THRESHOLD CONTROL REGISTER
DESTINATION ADDRESS = 1
BIT
POSITIONFUNCTIONDESCRIPTION
31-8Not UsedNo programming required.
7-0Power ThresholdThe THRESH
exceeds the threshold programmed here. The threshold is represented as an 8-bit fractional unsigned
value with the following format:
0
. 2-1 2-2 2-3 2-4 2-5 2-6 2-7.
2
Using this format, the possible range of threshold values is between 0 to 1.9961. Bit position 7 is the MSB.
TABLE 17. AGC LOOP PARAMETERS CONTROL REGISTER
BIT
POSITIONFUNCTIONDESCRIPTION
31Enable AGC0 = Gain error enabled to AGC Loop Filter.
1 = Gain error into AGC Loop Filter set to zero.
30-28 AGC Loop Gain
Exponent (E)
27-24AGC Loop Gain
Mantissa (M)
23-16AGC ThresholdThe AGC gain error is generated by subtracting the threshold value programmed here from the
These bits set the loop gain exponent as given by:
AGC Loop Gain Exponent = 2
where EEE corresponds to the 3-bit binary value programmed here. Thus, a gain range from 2-7 to 2
may be achieved for EEE = 000 to 111 Binary. Bit position 30 is the MSB. See Table 3 on page 11.
The loop gain mantissa is represented as a 4-bit unsigned value with the following format:
AGC Loop Gain Mantissa = 0. 2
This format provides a mantissa range from 0.0 to 0.9375 for mantissa settings from 0000 to 11 1 1 Binary .
Bit position 27 is the MSB. Mantissa resolution = 0.0625. See Table 2 on page 11.
magnitude value out of the Cartesian-to-Polar Converter. The binary format for the AGC Threshold is the
same as that for the Power Threshold given in Table 15 on page 32.
output is driven low when the magnitude output of the Cartesian-to-Polar Converter
DESTINATION ADDRESS = 2
-(7 + EEE)
-12-22-32-4
; 0.MMMM.
-14
AGC THRESHOLD
VALUE
1.1453 (42h)0
0.8108 (67h)-3
0.5740 (49h)-6
0.4064 (34h)-9
0.2877 (24h)-12
15-8AGC Upper LimitThe upper 8 bits of the AGC Accumulator set the AGC gain. The v alue p ro gr amm ed here sets upper limit
for AGC gain by specifying a limit for the upper 8 bit s of the AGC accumulator. If the accumulated sum
exceeds the upper limit, the accumulator is loaded with the limit. These bits are packed as eemmmmmm
where the e’s correspond to the exponent bits an d th e m’s correspond to the mantissa bits of Equation 8
(see also Figure 8). Bit position 15 is the MSB. By setting the AGC upper and lower limits to the same value ,
the AGC can be set to a fixed gain.
7-0AGC Lower LimitThe value programmed here sets the lower limit for the upper 8 bits of the AGC accumulator in a manner
similar to that described for the upper limit. If the accumulated sum falls below the lower limit, the
accumulator is loaded with the limit. The format for these bits is as described for the upp er limit. By settin g
the AGC upper and lower limits to the same value , t he A GC ca n be set to a fixed gain.
TABLE 18. CARRIER PHASE ERROR DETECTOR CONTROL REGISTER
DESTINATION ADDRESS = 3
BIT
POSITIONFUNCTIONDESCRIPTION
31-8Not UsedNo programming required.
7-6ReservedReserved. Set to 0 for proper operation.
RESULTING OUTPUT
LEVEL (dBFS)
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TABLE 18. CARRIER PHASE ERROR DETECTOR CONTROL REGISTER (Continued)
DESTINATION ADDRESS = 3
BIT
POSITIONFUNCTIONDESCRIPTION
5-2Phase OffsetThese bits set the phase offset added (modulo 2π) to the phase output of the Cartesian-to-Polar
Converter. The phase offset is represented as a 4-bit fractional 2’s Complement value with the following
binary format:
Phase Offset = -2
This format provides a range from 0.875 to -1 (0111 to 1000) which corresponds to phase offset settings
π/8 to -π respectively. Resolution of 22.5° is provided. Bit position 5 is the MSB.
from 7
1-0Shift FactorThe bits set the left shift required by the Carrier Phase Error Detector. These two bits specify a left shift
BIT
POSITIONFUNCTIONDESCRIPTION
31-8Not UsedNo programming required.
7-3ReservedReserved. Set to 0 for proper operation.
2-0Discriminator DelayThe frequency detector (discriminator) computes frequency by subtracting a delayed phase term from
of 0, 1, 2 or 3 places. MSBs are discarded and LSBs are zero-filled. Bit 1 is the MSB.
TABLE 19. FREQUENCY DETECTOR CONTROL REGISTER
the current phase term (d
set the delay as given by:
Delay = 2
where K is the 3-bit value programmed here. Delays of 1, 2, 4, 8, and 16 are possible.
0
. 2-12-22
DESTINATION ADDRESS = 4
-3.
θ/dt). A programmable delay is used to set the discriminator gain. These bits
K
,
TABLE 20. FREQUENCY ERROR DETECTOR CONTROL REGISTER
DESTINATION ADDRESS = 5
BIT
POSITIONFUNCTIONDESCRIPTION
31-8Not UsedNo programming required.
7-3Frequency OffsetThe s e b i ts set th e f r equency of fset added (modulo) to the frequency output of the discriminator. The frequency
2-0Shift FactorThese bits set the left shift required by the Frequency Error Detector. These two bits set a left shift of 0,
BIT
POSITIONFUNCTIONDESCRIPTION
31-8Not UsedNo programming required.
7ReservedReserved. Set to 0 for proper operation.
6Lead/Lag to Serial
Output Routing
offset is represented as a 5-bit fractional 2’s complement value with the following binary format:
Frequency Offset = -2
This format provides a range from 0.9375 to -1.0 (0111 to 1000). The range and resolution of the
frequency offset depend on the discriminator delay and input rate. The frequency offset is added to the
5 MSBs of the discriminator output. Note: Set the frequency offset to 0 when using frequency aided
acquisition with PSK waveforms.
1, 2, 3, or 4 places. Bit 2 is the MSB. Values greater than 4 are invalid. Note: Set the shift factor to 0 when
using frequency aided acquisition with PSK waveforms.
TABLE 21. CARRIER LOOP FILTER CONTROLREGISTER #1
0 = The Carrier Loop Filter’s Lag Accumulator is routed to the Serial Output Controller.
1 = The lead and lag paths in the Carrier Loop Filter are summed and routed to the Serial Output
Controller.
0
. 2-12-22-32
DESTINATION ADDRESS = 6
-4.
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TABLE 21. CARRIER LOOP FILTER CONTROL
DESTINATION ADDRESS = 6
BIT
POSITIONFUNCTIONDESCRIPTION
5Lead/Lag to Internal
NCO Routing
4-0Error AccumulationThese bits set the number of phase and frequency error measurements that are accumulated before the
BIT
POSITIONFUNCTIONDESCRIPTION
31-8Not UsedNo programming required.
7-6ReservedReserved. Set to 0 for proper operation.
5Lead Phase Error
Enable
4Lag Phase Error
Enable
3AFC Enable0 = Frequency error enabled to lag processing path of Carrier Loop Filter.
2Carrier Sweep Enable0 = Frequency sweep input to the lag path of the Carrier Loop Filter enabled.
1Invert Carrier Phase
Error
0Invert Carrier
Frequency Error
0 = Sum of lead and lag paths routed to the internal NCO. (32 MSBs of sum are routed).
1 = The lead term is routed to the internal NCO. (32 MSBs of lead term are routed).
Carrier and AFC Loop Filters are run. Since the Loop Filters can only accept new inputs every 6 CLKs
(normally at the symbol rate), the error accumulation is required to ensure that no phase or frequency
error outputs are missed when error terms are generated at a rate greater than 1/6 CLK (see “Carrier
Phase Error Detector” on page 18). The 5-bit value programmed here should be set to one less than the
desired number of error terms to accumulate. For example, setting these bits to 0011 (BINARY) would
cause 4 error terms to be accumulated. A total range from 1 to 32 is provided.
When error accumulation is used, divide the Lead Gain by the number of errors accumulated. Note that
the LAG Gain does not need to be scaled since it increases to compensate for the delay, since it is an
accumulator.
TABLE 22. CARRIER LOOP FILTER CONTROLREGISTER #2
DESTINATION ADDRESS = 7
0 = Carrier Phase Error enabled to lead processing path of loop filter.
1 = Carrier Phase Error to lead processing path of loop filter zeroed.
0 = Carrier Phase Error enabled to lag processing path of loop filter.
1 = Carrier Phase Error to lag processing path of loop filter zeroed (First Order Loop).
1 = Frequency error zeroed.
1 = Sweep input to Carrier Loop Filter zeroed.
0 = Carrier Phase Error is normal into Carrier Loop Filter.
1 = Carrier Phase Error is inverted into Carrier Loop Filter.
0 = Carrier Frequency Error is normal into AFC loop filter.
1 = Carrier Frequency Error is inverted into AFC Loop filter.
REGISTER #1 (Continued)
TABLE 23. CARRIER LOOP FILTER UPPER LIMIT CONTROL REGISTER
DESTINATION ADDRESS = 8
BIT
POSITIONFUNCTIONDESCRIPTION
31-0Carrier Loop Filter
Upper limit
BIT
POSITIONFUNCTIONDESCRIPTION
31-0Carrier Loop Filter
Lower limit
The 32-bit two’s complement value pr ogramme d here set s the up per sweep an d tracking limit of the Carrie r
Loop Filter by setting the upper limit of the loop filter’s lag accumulator. If the limit is exceeded, the upper 32
bits of the 40-bit accumulator are set to the limit, and the 8 LSBs are set to zero.
TABLE 24. CARRIER LOOP FILTER LOWER LIMIT CONTROL REGISTER
DESTINATION ADDRESS = 9
The 32-bit two’s complement value programmed here sets the Lower sweep and tracking limit of the Carrier
Loop Filter by setting the lower limit of the loop filter’s lag accumulator. If the running sum falls below the limit,
the upper 32 bits of the 40-bit accumulator are set to the limit, and the 8 LSBs are set to zero.
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TABLE 25. CARRIER LOOP FILTER GAIN(ACQ) CONTROL REGISTER
DESTINATION ADDRESS = 10
BIT
POSITIONFUNCTIONDESCRIPTION
31-24Not UsedNo programming required.
23-18ReservedReserved. Set to 0 for proper operation.
17-14Carrier Lead Gain
Mantissa (Acquisition)
13-9Carrier Lead Gain
Exponent (Acquisition)
8-5Carrier Lag Gain
Mantissa (Acquisition)
4-0Carrier Lag Gain
Exponent (Acquisition)
These bits are the 4 fractional bits of the lead gain mantissa shown as follows.
Lead Gain Mantissa = 0 1. 2
This format provides a mantissa range from 1.0 to 1.9375 for mantissa settings from 0000 to 11 1 1 Binary .
Bit position 17 is the MSB.
These bits set the lead gain exponent as given by:
Carrier Lead Gain Exponent = 2
where E corresponds to the 5-bit binary value programmed here. Thus, a gain range from
-1
-32
2
to 2
(relative to the MSB position of the NCO control word) may be achieved for E = 11 1 1 1 to 00000
Binary. Bit position 13 is the MSB.
Format same as lead gain mantissa. Bit position 8 is the MSB.
Format same as lead gain exponent. Bit position 4 is the MSB.
-12-22-32-4.
-(32-E).
TABLE 26. CARRIER LOOP FILTER GAIN (TRK
DESTINATION ADDRESS = 11
BIT
POSITIONFUNCTIONDESCRIPTION
31-24Not UsedNo Programming required.
23-18ReservedReserved. Set to 0 for proper operation.
17-14Carrier Lead Gain
Mantissa (Track)
13-9Carrier Lead Gain
Exponent (Track)
8-5Carrier Lag Gain
Mantissa (Track)
4-0Carrier Lag Gain
Exponent (Track)
BIT
POSITIONFUNCTIONDESCRIPTION
31-27ReservedReserved. Set to 0 for proper operation.
Format same as lead gain mantissa (see Table 25). Bit position 17 is the MSB.
Format same as lead gain exponent (see Table 25). Bit position 13 is the MSB.
Format same as lead gain mantissa (see Table 25). Bit position 8 is the MSB.
Format same as lead gain exponent (see Table 25). Bit position 4 is the MSB.
TABLE 27. FREQUENCY SWEEP/ AFC LOOP CONTROL REGISTER
DESTINATION ADDRESS = 12
) CONTROL REGISTER
26-23Sweep Rate Mantissa
(Acquisition)
22-18Sweep Rate Exponent
(Acquisition)
17-14AFC Gain Mantissa
(Acquisition)
13-9AFC Gain Exponent
(Acquisition)
Sets carrier track sweep rate used during acquisition (see “Frequency Sweep Block” on page 23). Format
same as lead gain mantissa (see Table 25). Bit position 22 is the MSB.
Sets carrier track sweep rate used during acquisition (see “Frequency Sweep Block” on page 23). Format
same as lead gain exponent (see Table 25). Bit position 22 is the MSB. M = 0000,
E = 00000 is 2
Sets Frequency Error Gain. Format same as lead gain mantissa (see Table 25). Bit position 11 is the
MSB.
Sets Frequency Error Gain. Format same as lead gain exponent (see Table 25). Bit position 4 is the MSB.
-28
.
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TABLE 27. FREQUENCY SWEEP/ AFC LOOP CONTROL REGISTER (Continued)
DESTINATION ADDRESS = 12
BIT
POSITIONFUNCTIONDESCRIPTION
8-5AFC Gain Mantissa
(Track)
4-0AFC Gain Exponent
(Track)
TABLE 28. CARRIER LAG ACCUMULATOR INITIALIZATION CONTROL REGISTER
BIT
POSITIONFUNCTIONDESCRIPTION
N/ACarrier Lag
Accumulator
Initialization
Sets Frequency Error Gain. Format same as lead gain mantissa (see Table 25). Bit position 11 is the
MSB.
Sets Frequency Error Gain. Format same as lead gain exponent (see Table 25). Bit position 4 is the MSB.
DESTINATION ADDRESS = 13
Writing this address initializes the lag accumulator with the contents of the 4 Microprocessor Interface
Holding Registers at the start of the next Carrier Loop Filter Computation cycle. The contents of the
holding registers should not be changed until after the start of a new compute cycle, since the current
contents of the holding registers are loaded at the compute cycle start. The Microprocessor Interface can
be used to read an Internal Status Register which signals when the lag accumulator load is complete (see
“Microprocessor Interface” on page 27). The contents of the holding registers are loaded into the 32
MSBs of the lag accumulator and the 8 LSBs are zeroed.
It is good practice to load the LAG Accumulators at the very end of a configuration load sequence.
TABLE 29. SYMBOL TRACKING LOOP CONFIGURATION CONTROL REGISTER
DESTINATION ADDRESS = 14
BIT
POSITIONFUNCTIONDESCRIPTION
31-16Not UsedNo programming required.
15-13ReservedReserved. Set to 0 for proper operation.
12-11Sampling Error Shift
Factor
10-9Modulation Order
Select
The sampling error shifter is provided to left shift the sampling error to full scale before input to the Symbol
Tracking Loop Filter . The magnitude of the sampling error varies with the number of symbol decision levels,
and a left shift of 1 to 4 places is provided as required by modulation order . Suggested settings are provided
in the following:
00 = x2 2 levels on each rail (BPSK, QPSK).
01 = x4 4 levels on each rail (8 PSK).
10 = x8 8 levels on each rail.
11 = x16 16 levels on each rail.
Note: Saturation is provided in case of overflow.
These bits set the threshold levels used by the symbol decision blocks in the Sampling Error detector. The
end-symbol samples on either the I or Q processing path are compared against the selected threshold set
to determine the expected symbol value used in calculating the transition midpoint. The threshold levels
can be set for up to 16ary signals on both the I and Q processing path. The decision thresholds are set as
as follows.
00 = 2ary signal (Use this setting for BPSK, QPSK, and OQPSK signals).
01 = 4ary signal.
10 = 8ary signal.
11 = 16ary signal.
The threshold levels are determined by equally dividing up the signal range by the order of the signal. For
example, a 2ary signal would divide the
signal would have thresholds at:
-0.5, 0, and +0.5.
~1.0 to -1.0 signal range by two forcing threshold at 0.0. A 4ary
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TABLE 29. SYMBOL TRACKING LOOP CONFIGURATION CONTROL REGISTER (Continued)
DESTINATION ADDRESS = 14
BIT
POSITIONFUNCTIONDESCRIPTION
8Single/Double Rail
Sampling Error
7-3Sampling Error
Accumulation
2Lead Sampling Error
Enable
1Lag Sampling Error
Enable
0Invert Sampling Error 0 = Sampling error normal.
TABLE 30. SYMBOL TRACKING LOOP FILTER UPPER LIMIT CONTROL REGISTER
BIT
POSITIONFUNCTIONDESCRIPTION
31-0Symbol Tracking
Loop Filter Upper
Limit
This bit sets whether sampling error is derived from symbol transitions on just the I rail (single rail) or both
the I and Q rails (dual rail). In single rail operation sampling error from the Q rail is nulled and only the I rail
is used. In dual rail operation the sampling error from both the I an Q rails is summed and then scaled by
one half.
0 = Dual Rail Operation.
1 = Single Rail Operation.
Note: Set to 1 for BPSK operation and 0 for QPSK operation.
These bits set the number of sampling error measurements to accumulate before running the Symbol Loop
Filter. The loop filter requires 8 CLKs to compute an output. The sampling error detector generates error
terms at the symbol rate. Thus, the error accumulator must be used if the symbol rate exceeds 1/8 CLK to
ensure that no error terms are missed (see “Sampling Error Detector” on page 17). The 5-bit value
programmed here is set to one less than the desired number of error terms to accumulate. For example,
setting these bits to 00011 (BINARY ) would cause 4 error terms to be accumulated. A total range from 1 to
32 is provided.
0 = Sampling error enabled to lead path of loop filter.
1 = Sampling error to lead path of loop filter zeroed.
Sampling error enabled to lag path of loop filter.
0 =
1 = Sampling error to lag path of loop filter zeroed (First Order Loop).
1 = Sampling error inverted.
DESTINATION ADDRESS = 15
The 32-bit two’s complement value programmed here sets the upper tracking limit of the Symbol Tracking Loop
Filter by setting the upper limit of the loop filter’s lag accumulator. If the limit is exceeded, the upper 32 bits of the
40-bit accumulator are set to the limit, and the 8 LSBs are set to zero.
TABLE 31. SYMBOL TRACKING LOOP FILTER LOWER LIMIT CONTROL REGISTER
DESTINATION ADDRESS = 16
BIT
POSITIONFUNCTIONDESCRIPTION
31-0Symbol Tracking
Loop Filter Lower
Limit
TABLE 32. SYMBOL TRACKING LOOP FILTER GAIN (ACQ) CONTROL REGISTER
BIT
POSITIONFUNCTIONDESCRIPTION
31-24Not UsedNo programming required.
23-18ReservedReserved. Set to 0 for proper operation.
17-14Symbol Tracking
Lead Gain Mantissa
(Acquisition)
The 32-bit two’s complement value programmed here sets the Lower tracking limit of the Symbol Tracking Loop
Filter by setting the lower limit of the loop filter’s lag accumulator. If the running sum falls below the limit, the upper
32 bits of the 40-bit accumulator are set to the limit, and the 8 LSBs are set to zero.
DESTINATION ADDRESS = 17
These bits are the 4 fractional bits of the lead gain mantissa shown as follows:
Symbol Tracking Lead Gain Mantissa = 01. 2
This format provides a mantissa range from 1.0 to 1.9375 for mantissa settings from 0000 to 1111 Binary.
Bit position 17 is the MSB.
-12-22-32-4.
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TABLE 32. SYMBOL TRACKING LOOP FILTER GAIN (ACQ) CONTROL REGISTER (Continued)
DESTINATION ADDRESS = 17
BIT
POSITIONFUNCTIONDESCRIPTION
13-9Symbol Tracking
Lead Gain Exponent
(Acquisition)
8-5Symbol Tracking Lag
Gain Mantissa
(Acquisition)
4-0Symbol Tracking Lag
Gain Exponent
(Acquisition)
TABLE 33. SYMBOL TRACKING LOOP FILTER GAIN (TRK) CONTROL REGISTER
BIT
POSITIONFUNCTIONDESCRIPTION
31-24Not UsedNo programming required.
23-18ReservedReserved. Set to 0 for proper operation.
17-14Symbol Tracking Lead Gain Mantissa
(Track)
13-9Symbol Tracking Lead Gain Exponent
(Track)
8-5Symbol Tracking Lag Gain Mantissa
(Track)
4-0Symbol Tracking Lag Gain Exponent
(Track)
These bits set the lead gain exponent as given by:
Symbol Tracking Lead Gain Exponent = 2
where E corresponds to the 5-bit binary value programmed here. Thus, a gain range from
-1
-32
to 2
2
Binary. Bit position 13 is the MSB.
Format same as lead gain mantissa. Bit position 8 is the MSB.
Format same as lead gain exponent. Bit position 4 is the MSB.
relative to the MSB position of the NCO control word may be achieved for E = 11111 to 00000
DESTINATION ADDRESS = 18
Format same as lead gain mantissa (see Table 32). Bit position 17 is the MSB.
Format same as lead gain exponent (see Table 32). Bit position 13 is the MSB.
Format same as lead gain mantissa (see Table 32). Bit position 8 is the MSB.
Format same as lead gain exponent (see Table 32). Bit position 4 is the MSB.
-(32-E),
TABLE 34. SYMBOL TRACKING LOOP FILTER LAG ACCUMULATOR INITIALIZATION CONTROL REGISTER
DESTINATION ADDRESS = 19
BIT
POSITIONFUNCTIONDESCRIPTION
N/ASymbol Tracking Loop
Filter Lag Accumulator
Initialization
Writing to this address initializes the lag accumulator with the contents of the four Microprocessor
Interface Holding Registers at the start of the next loop filter computation cycle. The contents of the
holding registers should not be changed until after the start of a new compute cycle since the current
contents of the holding registers are loaded at the compute cycle start. At a slow rate, it could take 1 low
rate symbol time to change. The Microprocessor Interface should be used to read an internal status
register which signals when the lag accumulator load is complete (see Table 13 in the “Microprocessor
Interface” on page 27). The contents of the holding registers are loaded into the 32 MSBs of the lag
accumulator and the 8 LSBs are zeroed.
It is a good practice to load the LAG accumulators at the very end of a configuration load sequence.
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TABLE 35. LOCK DETECTOR CONFIGURATION CONTROL REGISTER
DESTINATION ADDRESS = 20
BIT
POSITIONFUNCTIONDESCRIPTION
31-28ReservedReserved. Set to 0 for proper operation.
27False Lock
Accumulator Operation
26-20Dwell Counter
Pre-load
19-10Integration Counter
Pre-Load
(Acquisition)
9-0Integration Counter
Pre-Load (Track)
BIT
POSITIONFUNCTIONDESCRIPTION
31-16Lock Accumulator Pre-
Load
(Acquisition)
This bit selects the input to the False Lock Accumulator.
0 = Frequency Error input enabled to accumulator.
1 = False Lock Bit enabled to accumulator.
The Dwell Counter holds off the Lock Accumulator integration for the number of integration cycles
programmed here. The length of the integration cycle is set in the bit positions 19-10. The 7-bit value
programmed here should be set to 1 less than the desired hold off time in integration cycles. The pre-load
is zeroed during Track Mode. Only used during stepped acquisition mode.
The Integration Counter controls the number Phase Error samples accumulated by the Lock
Accumulator. The 10-bit number loaded here is set to two less than the number of Phase Error samples
desired in the Integration Period. Total Range 2 to 1025. Bit 19 is the MSB.
Function is identical to Acquisition Integration Counter Pre-Load. See previous.
TABLE 36. LOCK ACCUMULATOR PRE-LOADS CONTROL REGISTER
DESTINATION ADDRESS = 21
The lock threshold is set by an accumulator pre-load which is backed off from the accumulator full scale
by the threshold amount. The Lock Accumulator is 18 bits and the accumulator bit weightings relative to
the magnitude of the Phase Error input and the pre-load is as follows:
BIT WEIGHTING OF ACCUMULATOR PRE-LOAD
0
210 29 28 27......2
-12-2 2-3 2-4 2-5 2-6 2-7
. 2
BINARY POINT
11
The accumulator roll over is at the 2
15-0Lock Accumulator Pre-
Load (Track)
TABLE 37. FALSE LOCK ACCUMULATOR PRE-LOAD CONTROL REGISTER
BIT
POSITIONFUNCTIONDESCRIPTION
31-16False Lock
Accumulator
Pre-Load (Acquisition)
15-0False Lock
Accumulator
Pre-Load (Track)
Function is identical to Acquisition Lock Accumulation Pre-Load. See previous.
DESTINATION ADDRESS = 22
Depending on configuration, the input to the False Lock Accumulator is either the false lock indicator bit
or the magnitude of the frequency error detector output. Like the Lock Accumulator, the threshold is set
by an accumulator pre-load that is backed off from accumulator full scale. The False Lock Accumulator
can accumulate sums up to 18 bits, and the bit weightings of the false lock indicator bit and the frequency
error input relative to accumulator full scale are shown as follows.
BIT WEIGHTING OF ACCUMULATOR PRE-LOAD
210 29 28 27......2
BINARY POINT
The accumulator roll over is at the 2
See previous. The Lock Detector State Machine only uses the accumulator during the verify state during
which the Track parameters are used.
bit position.
0
-12-2 2-3 2-4 2-5 2-6 2-7
. 2
BIT WEIGHTING OF
FREQUENCY ERROR MAGNITUDE
11
bit position.
BIT WEIGHTING OF
PHASE ERROR MAGNITUDE
BIT WEIGHTING OF
FALSE LOCK INDICATOR BIT
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TABLE 38. ACQUISITION/TRACKING CONTROL REGISTER
DESTINATION ADDRESS = 23
BIT
POSITIONFUNCTIONDESCRIPTION
31-16Not UsedNo programming required.
15ReservedSet to 0 for proper operation.
14False Lock Detect
Enable
13Frequency Sweep
Mode
12-9Verify State LengthThese bits set the number of integration cycles over which carrier lock must be maintained before the
8-5False Lock SweepThese bits set the duration of forced frequency sweep before returning to the acquisition state.
4Lock Detector ControlThis bit selects whether the acquisition/tracking process is controlled externally by a microprocessor or
This bit enables the false lock detection during the verify state of state machine controlled acquisition.
The overflow of the False Lock Accumulator before the Integration Counter forces the false lock state. If
disabled, the overflow of the False Lock Accumulator has no effect on state machine operation.
0 = Disable False Lock.
1 = Enable False Lock.
Note: The false Lock Detector is designed for false lock detection on square wave data. For shaped
waveforms false lock detection should be disabl ed or freque ncy error shou ld be used.
This bit selects whether stepped or continuous frequency sweep mode is used (see “Lock Detector” on
page 23).
0 = Stepped Frequency Sweep (provided for microprocessor controlled acquisition mode).
1 = Continuous Frequency Sweep.
Lock State is declared. The verify state is used to make sure that lock detection was not the result of noise
or false lock. The 4-bit value programmed here sets the verify state from 0 to 15 Integration Periods.
When
continuous frequency sweep mode is selected, the programmed number represents the number of Lock
Accumulator integration cycles to sweep before returning to the acquisition state. In stepped frequency
sweep mode, the number represents the number of loop filter compute cycles over which to enable the
sweep input to the lag accumulator.
internally by the state machine. If microprocessor control is chosen, the lock detect accumulator
integrates for the programmed period of time and ignores accumulator roll over, if any. The Lock Detector
Accumulator halts after each Integration Period and waits to be restarted by the microprocessor. In
addition, the microprocessor must select the acquisition/tracking parameters, as well as enable the
Frequency Sweep Block.
0 = Microprocessor Control.
1 = Internal State Machine Control.
3Microprocessor
Acquisition/Track
Select
2Microprocessor LockThis bit controls the state of the lock bit (STATUS6) in the status output STATUS6-0 (see “Output
1ReservedSet to zero for proper operation.
0Microprocessor
Selector” on page 26). In addition, this bit sets the internal state machine to the locked state when Lock
Detector Control is switched from microprocessor control to state machine control. See Table 47 for the
STATUS bit information.
This bit is used to enable the output of the Frequency Sweep Block to the lag path of the Symbol Tracking
Loop Filter. This bit is only used under microprocessor control of the Lock Detector.
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TABLE 39. HALT LOCK DETECTOR FOR READING CONTROL REGISTER
DESTINATION ADDRESS = 24
BIT
POSITIONFUNCTIONDESCRIPTION
N/AStop Lock Detector for
Reading
BIT
POSITIONFUNCTIONDESCRIPTION
N/ARestart Lock Detector Writing this location restarts the Lock Detector State Machine following a read of the Lock Detector . Note:
TABLE 41. SOFT DECISION SLICER CONFIGURATION CONTROL REGISTER
BIT
POSITIONFUNCTIONDESCRIPTION
31-8Not UsedNo programming required.
7Slicer Output Format0 = Soft decision outputs are in sign/magnitude format.
Writing this location halts the Lock Detector State Machine at the end of t he curr ent L ock De tect or
Accumulator integration cycle. This function is provided so that the Lock Detector integrators can be
stopped for reading via the microprocessor interface (only useful when the Lock Detector is under
internal state machine control). Bit 7 of t he int erna l status r egist er ca n b e mon ito re d via t he
Microprocessor Interface to determine when the Lo ck Detector has stoppe d and is read y for read ing.
See Table 14 for information on the internal status bits. The Lock Detector will remain stopped until
restarted (see Restart Lock Detector Contro l Re gister : Table 40).
TABLE 40. RESTART LOCK DETECTOR CONTROL REGISTER
DESTINATION ADDRESS = 25
Stopping the Lock Detector for reading is not required in Microprocessor Control Mode since the Lock
Detector Accumulators stop at the end of each integration cycle. See also Table 45.
DESTINATION ADDRESS = 26
1 = Soft decision outputs are in two’s complement format.
6-0Soft Decision
Threshold
BIT
POSITIONFUNCTIONDESCRIPTION
31-16Not UsedNo programming required.
15-13ReservedSet to zero for proper operation.
12Serial Data Sync
Polarity
(SOF output)
11Serial Data Sync
Polarity
(COF output)
The input to the slicer is compared against thresholds which are 1x, 2x and 3x the value programmed
here. The slicer output depends on the relationship of the I or Q magnitude to the 3 soft thresholds as
given in Table 9. The threshold is programmed as a fractional unsigned value with the following bit
weightings:
-12-2 2-3 2-4 2-5 2-6 2-7
0. 2
Note: Since the signal magnitude on either the I or Q path ranges between 0.0 and
value should not exceed 1.0/3 = 0.33. Bit position 6 is the MSB.
TABLE 42. SERIAL OUTPUT CONFIGURATION CONTROL REGISTER
DESTINATION ADDRESS = 27
0 = SOFSYNC pulses “High” one serial clock before data word on SOF.
1 = SOFSYNC pulses “Low” one serial clock before data word on SOF.
Set to 0 for use with the HSP50110.
0 = COFSYNC pulses “High” one serial clock before data word on COF.
1 = COFSYNC pulses “Low” one serial clock before data word on COF.
Set to 0 for use with the HSP50110.
.
~1.0, the threshold
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TABLE 42. SERIAL OUTPUT CONFIGURATION CONTROL REGISTER (Continued)
DESTINATION ADDRESS = 27
BIT
POSITIONFUNCTIONDESCRIPTION
10Serial Clock Phase
Relative to Data
9-8Serial Clock DividerThese bits set the clock rate of SLOCLK.
7 Serial Clock Select for
COF Output
6-4Serial Word Length for
COF Output
3 Serial Clock Select for
SOF Output
2-0Serial Word Length for
SOF Output
0 = Rising edge of serial clock at center of data bit.
1 = Falling edge of serial clock at center of data bit. Set to 0 for use with the HSP50110.
0 = CLK is used as the serial clock.
1 = SLOCLK is used as the serial clock.
Note: If the HSP50210 is used together with the HSP50110, CLK must be selected as the serial clock for
the SOF and COF outputs, and the same CLK must be used by both chips.
0 = CLK is used as the serial clock.
1 = SLOCLK is used as the serial clock.
Note: If the HSP50210 is used together with the HSP50110, CLK must be selected as the serial clock for
the SOF and COF outputs, and the same CLK must be used by both chips.
7-4ReservedSet to zero for proper operation.
3-0Output SelectThese bits select which input signals are routed to the 20 output pins AOUT9-0 and BOUT9-0. The signal
TABLE 43. OUTPUT SELECTOR CONFIGURATION CONTROL REGISTER
DESTINATION ADDRESS = 28
selections are listed below in Tables 43A and 43B.
Definition of Signal Bus Names
DATA SIGNAL BUSSES
ISOFT(2:0) This bus is the I channel soft decision slicer output data, expressed in the data format set
QSOFT(2:0) This bus is the Q channel soft decision slicer output data, expressed in the data format set
IEND(7:1)This bus is the 7 MSBs of I end symbol sample into the soft decision slicer, in 2’s
QEND(7:1) This bus is the 7 MSBs of Q end symbol sample into the soft decision slicer, in 2’s
STATUS SIGNAL PARAMETER BUSSES
AGC(7:1) . . . . . .This bus is the 7 MSBs of the AGC Accumulator Register. (MSB = AGC7).
MAG (7:0) . . . . .This bus is the 8-bit magnitude output of the Cartesian to Polar converter, in unsigned
PHASE (7:0) . . .This bus is the 8-bit phase output of the Cartesian to Polar converter, in unsigned binary
FE(7:1) . . . . . . .This bus is the seven MSBs of the Frequency Error Detector Output Register, in 2’s
GE (7:1) . . . . . .This bus is the seven MSBs of the Gain Error (AGC) Accumulator Register, in 2’s
TE (7:1) . . . . . .This bus is the seven MSBs of the Bit Phase Error Detector Output Register, in 2’s
CARPE (7:1) . . .This bus is the seven MSBs of the Carrier Phase Error Detector Output Register, in 2’s
LKACC(6:0) . . .This bus is the seven LSBs of the Phase Error Accumulator Register in the Lock Detector,
LKCNT(6:0) . . .This bus is the seven LSBs of the Integration Counter in the Lock Detector, in one’s
NCOCOS(9:0) . .This bus is the 10-bit two’s complement output of the DCL NCO, in 2’s complement
by CW26 bit 7, with one sign bit (ISOFT2) and two soft decision bits.
by CW26 bit 7, with one sign bit (QSOFT2) and two soft decision bits.
complement format. (MSB = Iend7).
complement format. (MSB = Qend7).
binary format. (MSB = MAG7).
format. (MSB = PHASE7).
complement format. (MSB = FE7).
complement format. (MSB = GE7).
complement format. (MSB = TE7).
complement format. (MSB = PE7).
in unsigned offset binary format. (MSB = LKA CC6) I f accumu la tion Bi ts 14-17 = 1, then
Bits 7-13 are output as LKACC(6.0). These output s a re zero otherwise.
complement format. (MSB = LKCNT6) If Bits 7-9 of the accumulator are zero, then Bits
0-6 are output as LKCNT(6-0). These outputs are zero otherwise.
format. (MSB = NCOCOS7).
Applications for the Various Output Signals
ISOFT(2:0) and QSOFT(2:0)
These signals provide a simple interface to a FEC decoder. As the mo st likely to be used output bus, these
signals are included in all but one of the programmable multiplexer outpu t conf ig urations.
IEND(7:1) and QEND(7:1)
These signals are useful when input to a D/A converter and displayed on a n oscilloscope in the X-Y plot .
This will yield the constellation signal display with which analog modem designers are familiar.
STATUS(6:0)
These signals can be used in fault detection for use in BIT/BITE applications and are useful during system
debug.
AGC(7:1)
This signal is useful in monitoring the AGC operation, signal detection and antenna tracking applications.
Other single bit signals are provided for direct use in external AGC.
MAG(7:0) and PHASE(7:0)
These signals are useful in signal detection applications, where presence of a signal is represented by a
particular signal magnitude or phase.
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TABLE 43. OUTPUT SELECTOR CONFIGURATION CONTROL REGISTER (Continued)
DESTINATION ADDRESS = 28
BIT POSITIONFUNCTIONDESCRIPTION
FREQERR(7:1), GAINERR(7:1), BITPHERR(7:1), and CARPHERR(7:1)
These signals are useful in applications that need these signals output at the symbol rate and available
for hardwiring, rather than at the processor access rate. Configurations that use the DCL as a stand alone
demodulator and matched filter are examples of such applications.
LKACC(6:0) and LKCNT(6:0)
These signals are provided for applications which require a lock detection interface that is not processor
dependent. These signals are also useful in fault detection in BIT/BITE applications.
NCOCOS(9:0)
This signal is provided for use when the DCL is configured as a stand alone Loop Filter and NCO. This
signal can be useful in fault detection in BIT/BITE applications.
TABLE 44. UPDATE READ REGISTER CONFIGURATION CONTROL REGISTER
DESTINATION ADDRESS = 29
BIT
POSITIONFUNCTIONDESCRIPTION
N/ALoad Output Holding
Register for
Microprocessor Read
Loading the Address Register with this destination address samples the contents of the Carrier Loop
Filter Lag Accumulator, Symbol Tracking Loop Filter Lag Accumulator, and the AGC Accumulator. The
sampled accumulator values are loaded into the output holding registers for reading via the
Microprocessor Interface. Allow 6 CLKs until the output holding register is stable for reading.
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TABLE 45. INITIALIZE LOCK DETECTOR (μP CONTROL MODE) CONTROL REGISTER
DESTINATION ADDRESS = 30
BIT
POSITIONFUNCTIONDESCRIPTION
N/AInitialization of Lock
Detector Accumulators
BIT
POSITIONFUNCTIONDESCRIPTION
31-16Not UsedNo programming required.
15-6ReservedSet to 0 for proper operation.
5Initialize NCOThis bit is used to zero the feed back in the NCO’s phase accumulator . This is useful in setting the output
4Zero Symbol Tracking
Loop Filter
Accumulator
3Zero Carrier Loop Filter
Accumulator
2-0ReservedSet to 0 for proper operation.
Loading the address register with this destination address pre-loads all of the Lock Detector
Accumulators and resets the Integration Counters to restart the integration process. Note: A write to this
address only initializes the Lock Detector when it is in microprocessor control mode (see
Acquisition/Tracking Control Register; Table 38 on page 41).
TABLE 46. TEST CONFIGURATION CONTROL REGISTER
DESTINATION ADDRESS = 31
of the NCO to a known value.
0 = Enable normal NCO operation.
1 = Zero phase accumulator feedback for test.
This bit is used to zero the lag accumulator in the Symbol Tracking Loop Filter.
0 = Enable normal loop filter operation.
1 = Zero Lag Accumulator.
This bit is used to zero the lag accumulator in the Carrier Loop Filter.
0 = Enable normal loop filter operation.
1 = Zero Lag Accumulator.
TABLE 47. STATUS 6-0 SIGNAL DESCRIPTIONS
BIT
POSITIONFUNCTIONDESCRIPTION
6Carrier Lock0 = Lock Detector is not in locked state (Carrier Tracking Loop is not locked).
1 = Lock Detector has achieved the locked state (Carrier lock has been achieved).
5Acquisition/Track
indicator
4ReservedN/A.
3Frequency Sweep
Direction
2High PowerThis bit is one clock cycle long and indicates when the AGC is at its lower limit (see “AGC” on page 10
1Low PowerThis bit is one clock cycle long and indicates when the AGC is at its upper limit (see “AGC” on page 10
0Data Ready StrobeThis bit pulses “High” for one CLK synchronous with a new signal output on OUTB6-0 (see Output
0 = Tracking Parameters currently being used by Tracking Loops.
1 = Acquisition Parameters currently being used by Tracking Loops.
This bit indicates the direction of the frequency sweep selected by the Frequency Sweep input to the lag
path of the Carrier Tracking Loop Filter (Defined for upper sideband signals).
0 = Up (Sweep increasing in frequency).
1 = Down (Sweep decreasing in frequency).
and Table 17 on page 33).
0 = AGC above lower limit.
1 = AGC at lower limit.
and Table 17 on page 33).
0 = AGC is at or below its upper limit.
1 = AGC is above its upper limit.
Selector Control Register: Table 43 on page 44). For example if the lower 4 bits of the Output Selector
Register are set to 0010 (BINARY), This bit will pulse active on the same CLK that new FE7-1 data is
output.
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Appendix A
Noise Bandwidth Summary
For a given decimation rate, the double-sided noise
equivalent bandwidth is shown using various combinations
of the CIC filter and the compensation filters in the
HSP50110. Each combination of filters is also shown with
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.
NOTE:
7. θ
is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Standby Power Supply CurrentI
Input Leakage CurrentI
Output Leakage CurrentI
Clock Input HighV
Clock Input LowV
Logical One Input VoltageV
Logical Zero Input VoltageV
Logical One Output VoltageV
Logical Zero Output VoltageV
Input CapacitanceC
Output CapacitanceC
NOTES:
8. Power supply current is proportional to frequency. Typical rating is 4mA/MHz.
9. Output load per test circuit and C
10. Not tested, but characterized at initial design and at major process/design changes.
= 5.0V ±5%, TA = 0°C to +70°C (Commercial), TA = -40°C to +85°C (Industrial). Parameters with
CC
MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits
established by characterization and are not production tested.
VCC = Max, CLK = 52.6MHz
(Notes 8, 9)
VCC = Max, Outputs Not Loaded-500µA
VCC = Max, Input = 0V or V
VCC = Max, Input = 0V or V
VCC = Max, CLK3.0-V
VCC = Min, CLK-0.8V
VCC = Max2.0-V
VCC = Min-0.8V
IOH = -400µA, VCC = Min2.6-V
IOL = 2mA, VCC = Min-0.4V
f
= 5.0V ±5% , TA = 0°C to +70°C (Commercial), TA = -40°C to +85°C (Industrial), (Note 11) Parameters with
CC
MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits
established by characterization and are not production tested.
CP
CH
CL
SH
SL
48
52MHz
UNITSMINMAX
19-ns
7-ns
7-ns
7-ns
7-ns
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Electrical SpecificationsV
PARAMETERSYMBOL
Setup Time IIN9-0, QIN9-0, SYNC
Hold Time IIN9-0, QIN9-0, SYNC
Setup Time ISER, QSER, SSYNC to SERCLK t
Hold Time ISER, QSER, SSYNC FROM SERCLK t
Setup Time A0-2, C0-7 to Rising Edge of WR
Hold Time A0-2, C0-7 from Rising Edge of WR
to CLKt
WR
SERCLK to CLKt
CLK to AOUT9-0, BOUT9-0, COF , COFSYNC, SOF, SOFSYNC,
SMBLCLK, HI/LO
Read Address Low to Data Validt
CLK to Status Out on C0-7t
Hight
WR
Lowt
WR
Lowt
RD
LOW to Data Validt
RD
HIGH to Output Disablet
RD
Output Enablet
Output Disable Timet
Output Rise, Fall Timet
NOTES:
11. A C tests performed with C
Test V
12. Controlled via design or process parameters and not directly tested. Characterized upon initial design and after major process and/or design
changes.
13. Set-up time required to ensure action initiated by WR
, SLOCLK, LKINT, THRES
= 3.0V, V
IH
= 4.0V, VIL = 0V.
IHC
L
= 5.0V ±5% , TA = 0°C to +70°C (Commercial), TA = -40°C to +85°C (Industrial), (Note 11) Parameters with
CC
MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits
established by characterization and are not production tested. (Continued)
52MHz
, FZ_CT, FZ_ST to CLK t
, FZ_CT, FZ_ST FROM CLK t
= 40 pF, IOL = 2mA, and IOH = -400mA. Input reference level for CLK is 2.0V, all other inputs 1.5V.
or SERCLK will be seen by a particular CLK.
DS
DH
DSS
DSH
t
WS
t
WH
WC
SC
t
DO
ADO
CDO
WRH
WRL
RL
RDO
ROD
OE
OD
RF
8-ns
1-ns
8-ns
0-ns
15-ns
0-ns
15-ns (Note 13)
10-ns (Note 13)
-8ns
-26ns
-15ns
16-ns
16-ns
16-ns
-15ns
-10ns (Note 12)
-8ns
-8ns (Note 12)
-5ns (Note 12)
UNITSMINMAX
AC Test Load Circuit
C
L
AND I
S1
†
CCOP
IOH1.5VIOL
EQUIVALENT CIRCUIT
±
† Test head capacitance.
DUT
SWITCH S1 OPEN FOR I
49
CCSB
FN3652.5
July 2, 2008
Waveforms
www.BDTIC.com/Intersil
WR
C0-7, A0-2
FIGURE 26. TIMING RELATIVE TO WRFIGURE 27. OUTPUT RISE AND FALL TIMES
t
CLK
WRL
HSP50210
t
WRH
t
RF
t
WS
t
CP
t
CL
t
WH
t
CH
OUTA9-0,
OUTB9-0
OEA
OEB
2.0V
0.8V
,
t
OE
1.5V
1.7V
1.3V
1.5V
t
RF
t
OD
IIN9-0, QIN9-0,
SYNC,
FZ_CT, FZ_ST
AOUT9-0, BOUT9-0,
COF, COFSYNC,
SOF, SOFSYNC,
, SMBLCLK,
HI/LO
SLOCLK, LKINT, THRES
SERCLK, WR
C7-0
FIGURE 28. TIMING RELATIVE TO CLK
t
DS
t
DH
tSC; t
t
DO
RD
WC
t
CDO
A2-0
C0-7
FIGURE 29. OUTPUT ENABLE/DISABLE
t
RL
t
RDO
t
ROD
t
ADO
FIGURE 30. TIMING RELATIVE TO READ
SERCLK
t
SH
t
SL
t
t
DSS
DSH
ISER, QSER, SSYNC
FIGURE 31. SERCLK TIMING
50
FN3652.5
July 2, 2008
HSP50210
www.BDTIC.com/Intersil
Plastic Leaded Chip Carrier Packages (PLCC)
0.042 (1.07)
0.048 (1.22)
PIN (1) IDENTIFIER
0.020 (0.51) MAX
3 PLCS
C
L
D1
D
0.026 (0.66)
0.032 (0.81)
0.045 (1.14)
MIN
0.042 (1.07)
0.056 (1.42)
0.050 (1.27) TP
VIEW “A” TYP.
C
L
EE1
0.013 (0.33)
0.021 (0.53)
0.025 (0.64)
MIN
0.004 (0.10) C
0.025 (0.64)
0.045 (1.14)
D2/E2
D2/E2
A1
A
-C-
VIEW “A”
0.020 (0.51)
MIN
SEATING
PLANE
N84.1.15 (JEDEC MS-018AF ISSUE A)
84 LEAD PLASTIC LEADED CHIP CARRIER PACKAGE
R
SYMBOL
A0.1650.1804.204.57-
A10.0900.1202.293.04-
D1.1851.19530.1030.35-
D11.1501.15829.2129.413
D20.5410.56913.7514.454, 5
E1.1851.19530.1030.35-
E11.1501.15829.2129.413
E20.5410.56913.7514.454, 5
N84846
INCHESMILLIMETERS
NOTESMINMAXMINMAX
Rev. 2 11/97
NOTES:
1. Controlling dimension: INCH. Converted millimeter dimensions are
not necessarily exact.
2. Dimensions and tolerancing per ANSI Y14.5M-1982.
3. Dimensions D1 and E1 do not include mold protrusions. Allowable
mold protrusion is 0.010 inch (0.25mm) per side. Dimensions D1
and E1 include mold mismatch and are measured at the extreme
material condition at the body parting line.
4. To be measured at seating plane contact point.
-C-
5. Centerline to be determined where center leads exit plastic body.
6. “N” is the number of terminal positions.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implic atio n or other wise u nde r any p a tent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
51
FN3652.5
July 2, 2008
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