SANYO LC72714

Ordering number : ENN6871A
CMOS IC
LC72714W
Mobile FM Multiplex Broadcast IC
with On-Chip VICS Decoder
Package Dimensions
unit: mm
3190-SQFP64
[LC72714W]
12.0
10.0
Functions
•
•
•
0.18
1.25
0.15
33
48
49
1.25
32
0.5
17
64
1.25
•
•
•
•
Adjustment-free 76 kHz SCF bandpass filter
Built-in VICS decoder
MSK delay detection system based on a 1T delay.
Error correction function based on a 2T delay (in the
MSK detection stage)
Digital PLL based clock regeneration function
Shift-register 1T and 2T delay circuits
Block and frame synchronization detection circuits
Functions for setting the number of allowable BIC errors
and the number of synchronization protection
operations.
Error correction using (272, 190) codes
Built-in layer 4 CRC code checking circuit
On-chip frame memory and memory control circuit for
vertical correction
0.5
12.0
10.0
•
•
•
•
1.25
1
1.7max
The LC72714W is data demodulator ICs for receiving FM
multiplex broadcasts for mobile reception in the DARC
format. This IC includes an on-chip bandpass filter for
extracting the DARC signal from the FM baseband signal.
It also integrates a decoder circuit that performs the VICS
data processing on the same chip and can implement a
compact, multifunction VICS reception system. The
LC72714W is an improved version of the LC72710W that
features circuit improvements that allow a single tuner to
receive both the VICS data and the dGPS data supported
by the earlier device. Note that a contract with VICS
Center is required to evaluate this sample IC and to
produce end products that support VICS.
• 7.2 MHz crystal oscillator circuit
• Two power saving modes: STNBY and EC STOP
• Dedicated frame synchronization circuit for
simultaneous reception of dGPS and VICS data
• Applications can use either a parallel CPU interface
(DMA) or a CCB serial interface.
• Supply voltage: 2.7 to 3.6 V
16
0.1
Overview
0.5
0.5
SANYO: SQFP64
• CCB is a trademark of SANYO ELECTRIC CO., LTD.
• CCB is SANYO’s original bus format and all the bus
addresses are controlled by SANYO.
Any and all SANYO products described or contained herein do not have specifications that can handle
applications that require extremely high levels of reliability, such as life-support systems, aircraft’s
control systems, or other applications whose failure can be reasonably expected to result in serious
physical and/or material damage. Consult with your SANYO representative nearest you before using
any SANYO products described or contained herein in such applications.
SANYO assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other
parameters) listed in products specifications of any and all SANYO products described or contained
herein.
SANYO Electric Co.,Ltd. Semiconductor Company
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
92001TN (OT) No. 6871-1/29
LC72714W
Specifications
Absolute Maximum Ratings at Ta = 25°C, VSS = 0 V
Parameter
Symbol
Maximum supply voltage
Conditions
Ratings
VDD
Input voltage
Output voltage
Output current
VIN(1)
A0/CL, A1/CE, A2/DI, RST, STNBY
VIN(2)
Pins other than VIN(1)
V
–0.3 to VDD + 0.3
V
–0.3 to +7.0
V
VOUT(1)
DO
Pins other than VOUT(1)
IOUT(1)
INT, RDY, DREQ, and D0 to D15
0 to 4.0
Pins other than IOUT(1)
0 to 2.0
mA
20
mA
200
mW
ITTL
Allowable power dissipation
V
–0.3 to +7.0
VOUT(2)
IOUT(2)
Allowable output current (total)
Unit
–0.3 to +5.5
Pdmax
–0.3 to VDD + 0.3
Total for all the output pins
Ta ≤ 85°C
V
mA
Operating temperature
Topr
–40 to +85
°C
Storage temperature
Tstg
–55 to +125
°C
Allowable Operating Ranges at Ta = –40 to +85°C, VSS = 0 V
Parameter
Supply voltage
High-level input voltage
Low-level input voltage
Symbol
Conditions
VDD
Ratings
min
typ
max
Unit
2.7
3.6
V
VIH1
A0/CL, A1/CE, A2/DI, RST, STNBY
0.7 VDD
5.5
V
VIH2
DACK, WR, RD, CS, SP, BUSWD, A3, IOCNT1, IOCNT2
0.7 VDD
VDD
V
VIL1
Pins for which VIH1 applies
VSS
0.3 VDD
V
VIL2
Pins for which VIH2 applies
VSS
0.3 VDD
FOSC
XIN input sensitivity
VXI
With a sine wave input to XIN, capacitor coupling,
VDD = +2.7 to +3.6 V
400
900
mVrms
VMPX
With a 100% modulated composite signal input to
MPXIN, VDD = +3.3 V
120
500
mVrms
VMPX2
With a 100% modulated composite signal input to
MPXIN, VDD = +2.7 V
120
450
mVrms
Serial I/O
Input amplitude
This IC operates with a frequency precision of ±250 ppm
7.2
V
Oscillator frequency
MHz
Clock low-level period
tCL
A0/CL
0.7
µs
Clock high-level period
tCH
A0/CL
0.7
µs
Data setup time
tSU
A0/CL, A2/DI
0.7
µs
Data hold time
tHD
A0/CL, A2/DI
0.7
µs
CE wait time
tEL
A0/CL, A1/CE
0.7
µs
CE setup time
tES
A0/CL, A1/CE
0.7
µs
CE hold time
tEH
A0/CL, A1/CE
0.7
Data latch change time
tLC
A1/CE
Data output time
tDDO
DO, A0/CL
CRC4 change time
tCRC
CRC4, A0/CL
µs
0.7
277
µs
555
ns
0.7
µs
No. 6871-2/29
LC72714W
Allowable Operating Ranges: Parallel Interface at Ta = –40 to +85°C, VSS = 0 V
Parameter
Conditions
Ratings
min
typ
max
Unit
Address to RD setup
tSARD
A0/CL, A1/CE, A2/DI, A3, RD
20
ns
RD to address hold
tHARD
A0/CL, A1/CE, A2/DI, A3, RD, tWRDL=>250 ns
–20
ns
RD low-level width
tWRDL1
RD
280
RD low-level width (when RDY is used)
tWRDL2
RD
100
150
RD cycle wait
tCYRD
A0/CL, A1/CE, A2/DI, A3, RD
RDY width (Register read)
tWRDY
RDY
RD data hold
Parallel I/O
Symbol
tRDH
ns
280
60
RD, DATn
ns
ns
230
ns
0
ns
Address to WR setup
tSAWR
A0/CL, A1/CE, A2/DI, A3, WR
20
ns
WR to address hold
tHAWR
A0/CL, A1/CE, A2/DI, A3, WR
20
ns
WR cycle wait
tCYWR
A0/CL, A1/CE, A2/DI, A3, WR
150
ns
WR low-level width
tWWRL
WR
200
ns
WR data hold
tWDH
WR, DATn
0
RDY output delay
tDRDY
RD, RDY
0
Corrected output RD width
Corrected output RD width
(when RDY is used)
RDY width (corrected output read)
DACK to DREQ delay
tWDRD1
tWDRD2
tWDRDY
ns
RD (BUSWD = L 8 bits)
300
RD (BUSWD = H 16 bits)
540
RD (BUSWD = L 8 bits)
100
300
RD (BUSWD = H 16 bits)
300
540
ns
RDY (BUSWD = L 8 bits)
60
230
ns
RDY ((BUSWD = H 16 bits)
tDREQ
DREQ, DACK
DMA cycle wait
tCYDM
RD, DREQ
RD low-level width (DMA)
tWRDM
RD
Notes:
ns
50
ns
ns
300
ns
490
ns
260
ns
420
300
ns
ns
Application designs must take the RDY signal output delay into consideration if the RDY signal is used as the CPU bus wait signal.
When the RDY signal is used, the “RD low-level width” and the “Corrected output RD width” values express the basic timing (excluding the wait
time) settings for the CPU bus.
If the RDY signal is not used, (that is, if no wait states are inserted) the value of the RD low-level width will be 280 ns (minimum).
Electrical Characteristics at VDD = +2.7 to +3.6 V, within the allowable operating ranges
Parameter
Symbol
High-level input current
Input resistance
typ
max
Unit
Io = 1 mA, BCK, FCK, BLOCK, FLOCK,
CRC4, CLK16DATA
VDD – 0.4
VOH2
Io = 2 mA, INT, RDY, DREQ, D0 to D15
VDD – 0.4
VOL1
Io = 1 mA, Pins for which VOH1 applies
0.4
VOL2
Io = 2 mA, Pins for which VOH2 applies
0.4
V
VOL3
Io = 1 mA, DO, INT
0.4
V
VIN = 5.5 V, A0/CL, A1/CE, A2/DI, RST,
STNBY
1.0
µA
IIH1
IIH2
Low-level input current
Ratings
min
VOH1
High-level output voltage
Low-level output voltage
Conditions
IIL
Rmpx
Reference supply voltage output
Vref
Bandpass filter center frequency
Fc
V
V
VIN = VDDD, All input pins other than IIH1
VIN = VSSD, All input pins
V
1.0
µA
–1.0
µA
MPXIN – Vssa f = 100 kHz
50
Vref, Vdda = 3 V
1.5
V
76.0
kHz
FLOUT
kΩ
–3 dB bandwidth
Fbw
FLOUT
Group delay
Dgd
FLOUT
Gain
Gain
FLOUT – MPXIN f = 76 kHz
ATT1
FLOUT f = 50 kHz
25
dB
ATT2
FLOUT f = 100 kHz
15
dB
ATT3
FLOUT f = 30 kHz
50
dB
ATT4
FLOUT f = 150 kHz
50
Output off leakage current
IOFF
V0 = VDDD, DO
Hysteresis voltage
VHIS
A0/CL, A1/CE, A2/DI, A3, CS, RD, WR,
DACK, IOCNT1, IOCNT2, RST, STNBY
Stop band attenuation
Internal feedback resistor
Rf
Current drain
IDD
XIN, XOUT
19.0
–7.5
kHz
+7.5
20
µs
dB
dB
1.0
V
0.1 VDDD
1.0
12
µA
MΩ
20
mA
No. 6871-3/29
LC72714W
Vddd
FCK
BCK
FLOCK
BLOCK
DATA
CLK16
Block Diagram
LPF
Vssd
1T delay
Clock
regeneration
STNBY
RST
Synchronization
regeneration
Error correction:
layer 2 CRC
Timing
control
2T delay
7.2MHz
MSK correction
circuit
LPF
XOUT
PN decoding
Data
XIN
Vref
MPXIN
Anti-aliasing
filter
Address
76kHz
VICS processing
BPF
(SCF)
Memory array
Output control (CPU interface) and
layer 4 CRC detection circuit
Vdda
Vref
TIN
SP
D0 to D15
A0/CL
A1/CE
A2/DI
A3
DO
Vddd
BUSWD
INT
Vssd
DREQ
DACK
CS
RD
WR
RDY
CRC4
IOCNT1
IOCNT2
CIN
VREF
FLOUT
Vssa
INT
DO
NC
WR
RD
A0/CL
A1/CE
A2/DI
A3
CS
STNBY
RST
SP
BUSWD
Pin Assignment
32
49
TIN
D15
NC
D14
Vssa
D13
Vref
D12
MPXIN
D11
Vdda
D10
FLOUT
D9
CIN
LC72714W
D8
NC
D7
TPC1
D6
TPC2
D5
TEST
D4
TOSEL1
D3
TOSEL2
D2
Vssd
D1
XIN
D0
64
1
RDY
Vddd
Vssd
DACK
DREQ
BCK
CRC4
FCK
FLOCK
BLOCK
DATA
CLK16
IOCNT1
IOCNT2
Vddd
XOUT
16
(Top view)
No. 6871-4/29
LC72714W
Pin Functions
Pin No.
Pin
3
IOCNT1
Function
Data bus I/O control 1 (SP =
4
IOCNT2
Data bus I/O control 2 (SP = low)*1
13
DACK
DMA acknowledge (SP = low)*1
38
WR
Write control signal (SP = low)*1
39
RD
Read control signal (SP = low)*1
40
A0/CL
Address input 0 (SP = low) CCB CL input (SP = low)
41
A1/CE
1 (SP = low) CCB CE input (SP = low)
42
A2/DI
2 (SP = low) CCB DI input (SP = low)
43
A3
44
CS
46
RST
45
STNBY
I/O
Pin circuit
low)*1
Input
3 (SP = low)*1
Chip select input (SP = L)*1
System reset input (negative logic)
Standby mode (positive logic)
47
SP
48
BUSWD
60
TEST
58
TPC1
59
TPC2
As above
61
TOSEL1
As above
62
TOSEL2
As above
49
TIN
As above
5
CLK16
Clock regeneration monitor
6
DATA
Demodulated data monitor
SP = low: parallel, SP = high: serial
BUSWD = low: 8 bits, BUSWD = high: 16 bits
The test pin must be connected to the digital system ground (VSS).
Must be connected to the digital system power supply (VDD) or ground
(VSS) in normal operation.
9
FCK
Frame start signal output
10
BCK
Block start signal output
7
FLOCK
Outputs a high level during frame synchronization
8
BLOCK
Outputs a high level during block synchronization
11
CRC4
33
INT
12
DREQ
16
RDY
Input
Output
Level 4 CRC detection result output
External CPU interrupt request output
DMA request signal
Read ready signal
Data bus
17 to 24
D0 to D7
The bus width can be set to be either 8 bits or 16 bits by the BUSWD
pin (pin 48).
I/O
For data input, only the lower 8 bits (D0 to D7) are valid. *3
25 to 32
D8 to D15
Data bus (in 16-bit mode)
These pins are held in the output off state when BUSWD is low.
64
XIN
1
XOUT
Connections for the system clock crystal oscillator circuit.
The XIN pin can also be used as an external clock signal input.
53
MPXIN
Baseband (multiplex) signal input
55
FLOUT
Subcarrier output (76 kHz bandpass filter output)
Output
I/O
Input
Output
+
–
Continued on next page.
No. 6871-5/29
LC72714W
Continued from preceding page.
Pin No.
Pin
Function
I/O
Pin circuit
+
56
CIN
Subcarrier input (comparator input)
Input
–
Vref
Vdda
52
VREF
Reference voltage output (Vdda/2)
Output
Vssa
36
DO
CCB serial interface data output
NC
This pin must be left open
Output
37
50
57
54
VDDA
Analog system power supply
—
51
VSSA
Analog system ground
—
2, 15, 34
VDDD
Digital system power supply (+2.7 V to +3.6 V)
—
14, 35, 63
VSSD
Digital system ground
—
Notes: 1. This pin must be connected to VDDD or VSSD if the IC is used in serial interface mode (when SP is high).
2. A capacitor of at least 2000 pF must be inserted between VDDD and VSSD.
3. When used in the SP = high mode (as set by the serial interface), the D0 to D7 data bus lines must be connected to either VDDD or VSSD.
Control Registers
This IC includes both registers that can be read and registers that can be written. These registers can be accessed using
either the serial interface (CCB) or the parallel interface. The SP pin switches between these interfaces.
The initial values of the write registers are the data loaded into internal registers when a reset signal (RST) is received.
These values are recommended values that do not need to be changed during normal operation.
If the parallel interface is used, applications must hold the address fixed at 00H when reading out data to which error
correction has been applied. If the CCB interface is used, the application needs only to specify the CCB address (#FB).
The address 00H is an invalid address for writing.
The addresses other than those specified below are control addresses particular to the IC. Applications must not specify
those addresses.
Address
Register
1
BIC
R/W
Address
Register
Number of allowable BIC errors
2
Function
W
1
STAT
Status register
Function
R/W
R
SYNCB
Block synchronization: error protection count
W
2
BLNO
Block number register
R
3
SYNCF
Frame synchronization: error protection count
W
4
CTL1
Control register 1
W
5
CTL2
Control register 2
W
6
CRC4
Layer 4 CRC register
W
No. 6871-6/29
LC72714W
Number of Allowable BIC Errors
Address
Register
R/W
Initial value
01H
BIC
W
22H
BIT7
BIT6
BIT5
BIT4
Back protection
BIT3
BIT2
(LSB)
BIT1
BIT0
Forward protection
(LSB)
The synchronization circuit in this IC operates by recognizing a 16-bit BIC code. The number of allowable errors is the
number of incorrect bits allowed in those 16 bits. This data sets up separate values for forward protection mode (when
synchronized) and for back protection mode (when not synchronized).
The default value is to allow 2 incorrect bits in both forward and back modes. If the block synchronization discrimination
output (BLOCK) is used for discriminating whether or not FM multiplex data is present, we recommend setting the back
protection mode BIC allowable error count to 1 or 0.
Block Synchronization: Error Protection Count
Address
Register
R/W
Initial value
02H
SYNCB
W
17H
BIT7
BIT6
BIT5
BIT4
Back protection
BIT3
BIT2
(LSB)
BIT1
BIT0
Forward protection
(LSB)
The synchronization protection count can be set separately for both forward and back protection. The count conditions
for the protection counts are as follows.
• Back protection mode (not synchronized: BLOCK = low)
If the timing of the IC internal synchronization free-running counter matches the timing of the received BIC, the
protection count is incremented by 1. Contrarily, if the timings of the IC internal counter and the received BIC do not
match, the protection counter is cleared to 0. The timing of the count is the timing of the IC internal counter.
• Forward protection mode (synchronized: BLOCK = high)
In reverse to the back protection mode, if the timing of the IC internal free-running counter does not match the
detection timing of the received BIC, the protection counter is incremented, and if the timings match, the protection
counter is cleared to 0.
Figure 1 shows the states of the protection counter for the cases where the forward and back protection counts are both 3.
This IC defines the value of the protection counter to be 1 at the point that a match or a discrepancy occures between the
IC internal timing and the timing of the received BIC. For example, when the value of the back protection count is 2, the
IC internal timing and the timing of the received BIC will have matched two times consecutively.
If the protection data is set to new values, for example if the protection counts are set to 3 as assumed in figure 1,
applications must send values which are 1 less than the intended value; in this case 22H. Similarly, if the value is set to
00H, the protection counts will, by definition, be set to 1 for both the forward and back directions. However, note that the
resulting operation will be equivalent to there being no protection circuit. The default values are 8 for the forward
protection count and 2 for the back protection count.
If the block synchronization output (BLOCK) is used for discriminating whether or not FM multiplex data is present, we
recommend setting the block synchronization back protection count to a value that is more strict than the default value.
(That is, we recommend replacing the default value of 2 with a value of 3 or higher.)
BIC
Received data
1
2
0
3
1
0
Reset
Synchronization
counter BIC position
1
Block
2
3
* Assumes that the forward and
back protection counts are 3.
Figure 1 Block Synchronization Protection Operation (Forward → Back → Forward)
No. 6871-7/29
LC72714W
Frame Synchronization: Error Protection Count
Address
Register
R/W
Initial value
03H
SYNCF
W
17H
BIT7
BIT6
BIT5
Back protection
BIT4
BIT3
(LSB)
BIT1
BIT0
Forward protection
BIT2
(LSB)
This IC detects the BIC characteristic inflection points which occur at four places in a single frame, and increments or
decrements a protection counter depending on whether or not they match the IC internal frame synchronization timing
counter.
As is the case with the block synchronization error protection value, applications must set these to values one less than
the desired protection count. The default values are 8 for the frame synchronization forward protection count and 2 for
the back protection count.
Control Register 1
Address
Register
R/W
Initial value
04H
CTL1
W
00H
BIT7
BIT6
CRC4_RST DO_MOVE
BIT5
BIT4
INT_MOVE SYNC_RST
BIT3
BIT2
BIT1
BIT0
EC_STOP
VEC_HALT
*
*
*: BIT0 and BIT1 are unused.
• VEC_HALT
0: Vertical correction and the second horizontal correction processing are performed. (default)
1: Vertical correction and the second horizontal correction processing are not performed.
All IC operations related to vertical correction and the second horizontal correction are stopped by setting this flag.
Note that in data output, only data to which the first horizontal correction has been applied will be output.
• EC_STOP
0: All functions operate. (default)
1: Only the MSK detection circuit and the synchronization regeneration circuit operate.
This flag stops all operations relating to error correction (including RAM access), data output, and other operations.
While all IC operations are stopped in standby mode, MSK demodulation, the synchronization circuit, the serial data
input circuit, and the layer 4 CRC circuit continue to operate in this mode.
• SYNC_RST
0: (default)
1: Resets just the synchronization regeneration circuit.
Clears the synchronization status and the synchronization protection status in the synchronization circuit block, and
sets the circuit to the unsynchronized state. This allows the circuit to quickly pull in to frame synchronization when
the frame synchronization is incorrect for the new reception data following tuning, when the radio has been tuned to
a new station. While this flag is used for synchronization related sections of the system, it does not initialize the
registers that set the number of allowable BIC errors, the block synchronization forward and back protection counts,
and the frame synchronization forward and back protection counts. Also note that during a synchronization block
reset, the INT signal is not output and the DO pin outputs a high level (high-impedance).
This flag is not automatically reset to 0. Applications must send a 0 value after setting this flag.
• INT_MOVE
0: Data is only output when error correction has completed, layer 2 CRC has completed, and the data was received with
the circuit synchronized. (default)
1: All data is output. (Operation is identical to that of the LC72700E.)
In the default state, this IC only outputs data that has been fully error corrected and that was received in both block
and frame synchronization. (This also includes the layer 2 CRC check.)
To acquire all data as provided by the LC72700, applications must set both this flag and the VEC_OUT (BIT2) flag
in control register 2 as described below.
• DO_MOVE (Valid only when SP is high.)
0: The high state (high impedance) is held at all times other than when data is being output. (default)
1: Operate identically to the LC72700 when changes are linked to the INT signal, i.e. when both INT_MOVE and
VEC_OUT are set to 1.
• CRC4_RST
0: (default)
1:Reset the layer 4 CRC detection circuit.
This flag is not automatically reset to 0. Applications must send a 0 value after setting this flag.
No. 6871-8/29
LC72714W
Control Register 2
Address
Register
R/W
Initial value
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
05H
CTL2
W
00H
SUBBLK
BLK_RST
DACK
DREQ
RDY
VEC_OUT
DMA_RD
DMA
• DMA (Valid only when SP is low.)
0: Do not use DMA transfer for readout of post-error correction data. (default)
1: Use DMA transfer for readout of post-error correction data.
• DMA_RD (Valid only when SP is low.)
0: Use the RD signal as the DMA transfer read control signal. (default)
1: Use the DACK signal as the DMA transfer read control signal.
• VEC_OUT
0: Do not perform post-horizontal correction output when vertical correction processing is not performed. (default)
1: Output all data, even when vertical correction processing is not performed. (Operation identical to that of the
LC72700)
When this flag is set and a frame of data with absolutely no errors is received, data that is completely identical to the
corresponding post-horizontal correction data is output with the timing of the output of post-vertical correction data,
even if vertical correction is not performed.
This flag must be set to create interface specifications identical to those of the LC72700.
• RDY (Valid only when SP is low.)
0: The RDY output is issued with timing 1. (default)
1: The RDY output is issued with timing 2.
• DREQ (Valid only when SP is low.)
0: Negative logic is used for the polarity of the DREQ signal. (default)
1: Positive logic is used for the polarity of the DREQ signal.
• DACK (Valid only when SP is low.)
0: Negative logic is used for the polarity of the DACK signal. (default)
1: Positive logic is used for the polarity of the DACK signal.
• BLK_RST
0: (default)
1: Resets the block synchronization circuit only.
Sets the block synchronization status to unsynchronized and clears the block synchronization protection counter.
However, note that this has no effect on the frame synchronization functions. Also note that during a
synchronization block reset, the INT signal is not output and the DO pin outputs a high level (high-impedance).
This flag is not automatically reset to 0. Applications must send a 0 value after setting this flag.
• SUBBLK
0: Normal status. (default)
1: Set to 1 when a substation (for example a dGPS station during VICS reception) is temporarily received.
The SUBBLK and BLK_RST flags are mainly used when receiving and processing VICS data and dGPS data at the
same time. (See page 28.)
RD
DATn
Valid
output
RDY
Timing1
RDY
Timing2
RDY Signal Output Timing
No. 6871-9/29
LC72714W
Layer 4 CRC Register
Address
Register
R/W
Initial value
06H
CRC4
W
00H
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
(LSB)
This is the data group write register used for the layer 4 CRC check. It is used only when the parallel interface is used.
Applications should specify the dedicated CCB address when using the serial interface.
Status Register
Address
Register
R/W
Initial value
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
01H
STAT
R
—
VH
BLK
FRM
ERR
PRI
HEAD
CRC4
*
*: BIT0 is unused.
• VH
0: Indicates data for which only horizontal correction was performed.
1: Indicates data for which after horizontal correction, vertical and then second horizontal correction were performed as
well.
• BLK
0: Indicates data that was received with block synchronization unsynchronized.
1: Indicates data that was received with block synchronization synchronized.
• FRM
0: Indicates data that was received with frame synchronization unsynchronized.
1: Indicates data that was received with frame synchronization synchronized.
• ERR
0: Indicates data for which error correction completed and no errors were detected in the level 2 CRC check.
1: Indicates data for which error correction was not possible or for which errors were detected in the level 2 CRC
check.
• PRI
0: Indicates data that was inferred to be data block data by the frame synchronization circuit.
1: Indicates data that was inferred to be parity block data by the frame synchronization circuit.
• HEAD
0:
1: Indicates data that was inferred to be in the frame head block by the frame synchronization circuit.
This flag is valid only when VH is 0.
• CRC4
0: Indicates that the layer 4 CRC detection circuit division registers were not all zeros.
1: Indicates that the layer 4 CRC detection circuit division registers were all zeros, i.e. that there were no errors.
The result at the point immediately prior to register readout is loaded into this flag.
Block Number Register
Address
Register
R/W
Initial value
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
02H
BLNO
R
—
BLN7
BLN6
BLN5
BLN4
BLN3
BLN2
BLN1
BLN0
Indicates the block number or the parity block number of the output data.
A single frame consists of data blocks numbered 0 to 189 and parity blocks numbered 0 to 81. Output following vertical
correction does not include parity block data.
The value of the block number register is undefined if VEC_HALT (bit 2 in control register 1) is set to 1.
No. 6871-10/29
LC72714W
Data Update Timing for Read Registers
The data in the two read registers (the status register at address 01H and the block number register at address 02H) is
updated in the 1 ms interval between 1 ms prior to the output of the interrupt control signal (INT) and a point
immediately before the INT output.
In normal processing, when an interrupt occurs, the application will first determine the nature of the data packet that will
be output by the current interrupt signal by reading out the status register, and determine if it is necessary to read out that
data. For example, if error correction failed and the erroneous data is not required, the application should simply wait for
the next interrupt.
If the CCB interface is used, the application reads out the data from CCB address #FB, and determines the status from the
additional 16 bits of data. It then either reads out the following data or sets the CE signal low to cancel the readout.
Applications can also read out data asynchronously with respect to the interrupt signal. In this case, the application
checks the current reception status by reading out the status register and checking bit 6 (data received in the block
synchronized state) and bit 5 (data received in the frame synchronized state). In this case, using data for which bit 7 (VH)
is 0 provides superior real time characteristics.
CPU Interface Timing <Parallel Mode>
• Register Read Timing
tCYRD
tWRDL1, tWRDL2
A0 to A3
CS
tSARD
tHARD
RD
tDRDY
RDY
tWRDY
tRDH
DATn
Valid
output
* tHARD stipulates the earliest timing for A0 to A3 and CS.
No. 6871-11/29
LC72714W
• Register Write Timing
tWWRL
tCYWR
A0 to A3
CS
tHAWR
tSAWR
WR
tWDH
DATn
• Post-Correction Data Read Timing
tCYRD
tWDRD1, tWDRD2
*: A0 to A3: When post-correction data is read,
A0 to A3 will be held fixed at 0.
A0 to A3
CS
tSARD
tDRDY
RD
tWDRDY
RDY
tRDH
DATn
Valid
output
Valid
output
No. 6871-12/29
LC72714W
• Post-Correction Data Read Timing (DMA)
tDREQ
tWRDM
DREQ
DACK
RD
A0 to A3
CS
tRDH
DATn
tCYDM
*: A0 to A3: When post-correction data is read, A0 to A3 will be held fixed at 0.
*: DREQ and DACK: The polarity of these signals can be set.
*: Applications can select whether the DR or DACK signal is used for readout.
Layer 4 CRC Detection Circuit <Parallel Interface>
This function provides data group error detection, i.e. layer 4 CRC. When the stipulated number of bytes of data group
data and the CRC detection word (16 bits) are written to the layer 4 CRC register (address 6), if either the CRC4 pin
outputs a high level or the CRC4 flag (bit 1 in the status register at address 1) is set to 1 then there were no errors in the
data. The CRC4 pin or CRC4 flag in the status register outputs a high level if the IC internal CRC detection register bits
are all in the logic 0 state.
When this function is used to perform a layer 4 CRC check, applications must initialize the IC internal CRC detection
register before transferring the data for a single data group. This initialization is performed by sending data for bit 7
(CRC4_RST) in control register 1. Note that since this initialization flag is not automatically reset to 0, after the
application sets this flag it must then send another data item that resets it to 0 before sending the layer 4 CRC check data.
If there were no errors in all the received data groups, the CRC register will, necessarily, be all zeros after the CRC check
for a given data group. Therefore, as long as there are no errors detected in the layer 4 CRC check, the application does
not need to initialize the CRC detection register again using the control register as described above. There is no upper
limit on the total data length of data groups that can be transferred. Also, when the serial interface issued, the CCB
transfers can be divided into multiple transfer operations. The generating polynomial G(x) for the CRC code is as
follows. G(x) = X16 + X12 + X5 + 1
Structure of the Post-Correction Output Data <Parallel Interface>
The total length of the prepared output data is always 176 bits, i.e. 22 bytes. The layer 2 CRC data (14 bits) and the parity
data (82 bits) are not output. The data in each packet in the post-correction data is output in order starting at the
beginning in 8- or 16-bit units. BIC codes are not output.
When the CPU reads out the data, it can easily select the data by checking the status register first. The CPU can then
simply ignore data determined to be unnecessary without having to read it out by simply waiting until the next interrupt
arrives.
Data block (176 bits) Post-error correction data
Structure of a Single Data Packet (Total length: 272 bits. BIC is not included.)
Layer 2 CRC (14 bits)
Parity (82 bits)
*: This data is not output.
No. 6871-13/29
LC72714W
CPU Interface <CCB Mode>
CCB Format
Data is input and output using the CCB (Computer Control Bus) format, which is Sanyo’s audio IC serial bus format.
This IC uses an 8-bit address CCB with the address shown below. The CCB address is sent while CE is low, and the
CCB I/O mode is determined when CE is set high.
CCB address
I/O mode
Item
B0
B1
B2
B3
A0
A1
A2
A3
Input
0
1
0
1
1
1
1
1
16-bit control data input
Output
1
1
0
1
1
1
1
1
Data corresponding to the number of clock (CL) cycles is output
Input
0
0
1
1
1
1
1
1
Data input mode for the layer 4 CRC detection circuit (8-bit units)
Output
1
0
1
1
1
1
1
1
Register output only
Data input (Register write)
Data is stored in an IC internal register. The CCB address #FA and 16 bits of data (DI0 to DI15) are input to the DI pin.
The bits are assigned as follows. Although DI12 to DI15 are unused data, arbitrary values must be provided to complete a
full 16 bits of data.
See the “Control Register” section earlier in this document for details on the register contents and addresses.
Details on writing to the layer 4 CRC check register are described later in this document. (The CCB address #FC is used
for this function.)
DI0
DI1
DI2
DI3
DI4
DI5
DI6
DI7
DI8
DI9
DI10
DI11
BIT0
BIT1
BIT2
BIT3
BIT4
BIT5
BIT6
BIT7
BIT0
BIT1
BIT2
BIT3
(LSB)
Input data (8 bits)
(MSB)
tEL
DI12 to DI15
Unused data
Register address
tES
CE
tCH
tEH
tCL
CL
tSU
tHD
B0
DI
B1
B2
B3
A0
A1
A2
A3
DI0
DI1
DI2
DI13
DI14
DI15
tLC
Internal data latch operation
Data Output (Post-correction data output)
The IC outputs packet data to which error correction processing has bee applied. The application inputs the CCB address
#FB to DI.
tEL
tES
CE
tCL
tCH
CL
tSU
DI
tHD
B0
B1
B2
B3
A0
A1
A2
A3
tDDO
DO
DO0
DO1
DO2
DO285 DO286 DO287
*: The DO pin is normally left open.
Since the DO pin is an n-channel open-drain output, the data change time from a low-level
output to a high-level output differs due to the pull-up resistor.
No. 6871-14/29
LC72714W
Structure of the Post-Correction Output Data <CCB Interface>
Post-error correction data can be output by using CCB address #FB. Although there are up to 288 bits of valid data that
can be output, it is possible to stop clock input (CL input) and set CE to the low level, and output the remaining data on
the next interrupt with no harmful effects whatsoever.
• The maximum amount of data that can be output is 288 bits (36 bytes), and the contents of the status register (STAT)
and the block number register (BLNO) are added as the first two bytes.
• The contents of the STAT and BLNO registers are output LSB first.
• The post-correction data is output in order starting with the first bit in each single block of data.
• The BIC code is not output.
• The values of the output data are not guaranteed if multiple data read operations are performed for a single interrupt
signal (INT).
STAT (8 bits)
BLNO (8 bits)
DO0 to DO7
DO8 to DO15
Data section (176 bits) Post-error correction data
DO16 to DO191
Layer 2 CRC (14 bits)
Parity (82 bits)
DO192 to DO205
DO206 to DO287
Layer 4 CRC Check Circuit <CCB Interface>
The basic outline of this operation is the same as that described in the Layer 4 CRC Detection Circuit <Parallel
Interface> section earlier in this document. The data group data used for this error detection operation is sent to the IC
using the CCB interface. The value #FC is used as the CCB address.
The data group data is transferred in 8-bit units. There is no upper limit on the amount of data that can be transferred (the
value N in the figure below), and the data transfer may be divided into multiple operations.
tEL
tES
CE
tCH
tEH
tCL
CL
tSU
tHD
B0
DI
B1
B2
B3
A0
A1
A2
A3
CR0
CR1
CR2
N-2
N-1
N
tCRC
CRC4 pin output
Note: The number of items, N, refers to
the number of 8-bit items.
CRC4 pin output after N items
have been transferred.
Register Output
The IC internal status and block number registers are special-purpose registers that can be read out by applications. (See
the discussion of the read register data update timing on page 12.)
The application inputs the CCB address #FD to DI. The status register data is output first followed by the block number
register data.
tEL
tES
CE
tCH
tCL
CL
tSU
DI
tHD
B0
B1
B2
B3
A0
A1
A2
A3
tDDO
DO
ST0
ST1
ST2
BLN5 BLN6
BLN7
No. 6871-15/29
LC72714W
Notes on Operation during Resets and in Standby Mode
Reset Signal
The reset operation is executed when the supply voltage (VDD) rises above 2.5 V (2.5 V in the LC72710LW) and the
RST pin input level is held at or below VIL for 300 ns or longer. (See the figure below.)
When power is first applied, or when power is removed and applied again, always apply a reset before using this IC.
VDD voltage
2.5 V
VIH
RST
VIL (0.3 VDD)
300 ns (min)
Pin States during Reset
Low level:CLK16 (5), DATA (6), FLOCK (7), BLOCK (8), FCK (9), BCK (10)
High level: INT (33), RDY (16), CRC4 (11), DREQ (12)
Open: D0 (17) to D15 (32), DO (36)
Reset Operating Range
The states of the output pins as the result of a reset signal are stipulated in the "Pin States during Reset" item above. The
IC internal flip-flops are all reset. While the shift registers used for delay are also reset, the memory array is not
influenced by this operation. However, since memory is not refreshed, data cannot be retained. The crystal oscillator
circuit is not stopped.
Post-Reset Data Input
After a reset operation has completed, if at least one clock cycle (about 278 ns when the IC's main clock is 3.6 MHz)
elapses, the register write circuit will be functional. (That is, the IC can accept data.)
Notes on Standby Mode
The IC is set to standby mode by applying a high level to the STNBY pin. Since all IC operations are stopped in this
mode, the state is essentially equivalent to removing power from the IC. (Note that after clearing standby mode,
applications must wait the oscillator stabilization time before using the IC.)
The pin output states during standby mode are the same as those states during a reset as described above. The internal
VICS registers are cleared and the status flag values are not retained.
Output Conditions for Post-Error Correction Output (Default Mode)
(1) For each block (272 bits) of received data, the IC applies (272, 190) code error correction and a layer 2 CRC error
check. After the error correction has completed, the IC prepares to transfer the data to the CPU and outputs an
interrupt signal from the INT pin. This is referred to as horizontal correction output.
(2) Note that under the default operating conditions, this interrupt signal is not output unless the corresponding output
data meets the following three conditions.
• Error correction completed correctly and no errors were discovered in the layer 2 CRC check.
• The data was received in both block and frame synchronization.
• The data is packet data.
(3) If the data could not be corrected in horizontal correction, product code correction is performed in frame units and
a second horizontal correction operation is performed for this data that could not be corrected by the first
horizontal correction. This sequence of operations is called vertical correction.
The output conditions for data that can be acquired after vertical correction are as follows.
• The data that could not be corrected by horizontal correction only, but that was corrected by vertical correction.
• The data is packet data.
Continued on next page.
No. 6871-16/29
LC72714W
Continued from preceding page.
This means that data that was fully corrected by horizontal correction is not output. Also, packet data that could
not be corrected by either horizontal correction or vertical correction is not output. Furthermore, post-vertical
correction parity packet data is also not output.
(4) Applications can clear the INT signal selection conditions described in (2) and (3) above by setting bit 5
(INT_MOVE) in the control register.
(5) Vertical correction is performed when all of the packet data in a frame is received in frame synchronization and
furthermore when it was not possible to correct all of the packet (block) data with horizontal correction.
Vertical correction is not performed if one frame of data with no errors was received or the receiver was not in
frame synchronization during reception.
To prevent incorrect correction, error correction using vertical correction is not performed for packets error
correction using horizontal correction fully completed and for packets that had no errors.
(6) Under the default settings, if vertical correction is not performed, the corresponding post-vertical correction output
is not output.
Applications can specify the post-vertical correction data to be output regardless of whether or not vertical
correction is performed by setting bit 2 (VEC_OUT) in control register 2.
Note 1. In this case, if data with absolutely no errors is received, completely identical data will be output twice,
once as horizontal correction output, and once as vertical correction output. This status is identical to the
output status of the LC72700E.
Note 2. Immediately after power is applied, undefined data that is, in principle, not required by applications, will
be output as post-vertical correction data.
CPU Interface Basic Limitations
To save internal memory, this IC limits its output data buffer to the smallest size possible. Since the data received by the
IC is written to memory continuously without interruption, the post-correction data in the output data buffer that should
be read out may be overwritten by the following data if readout of the data is delayed.
The output timing for post-correction data, both horizontal and vertical, is stipulated as follows for this IC.
(1) When the IC completes preparation of the output data, it drops the INT pin to the low level as a transfer request.
(2) During data output, there are periods when only horizontal data can be read out, and there are other periods when
both horizontal data and vertical data can be read out in a time-division multiplexed manner.
(3) Applications must complete the data transfer operation within 9 ms after the INT pin goes low. If only posthorizontal correction data is output, the data transfer may be performed within an 18 ms period.
After the stipulated period, the next data will be written to the output buffer replacing the previous data, even if
the CPU is reading out the data.
(4) The amount of data that can be read for a single transfer request (INT) for each of the horizontal and vertical data
is one block only. The post-vertical correction data is output in order starting with block number 1 after vertical
correction processing completes. The parity block data is not output.
18 ms
INT
Horizontal data only
output
Horizontal and vertical
data output
1 ms
Horizontal data
output period
Period during which data
retention is not guaranteed
Horizontal data
output period
Vertical data output period
68 µs
68 µs
Figure 2 External Interface - Basic Timing
No. 6871-17/29
LC72714W
Notes on Data Output Timing (Relationship with the received data)
Figure 3 shows the timing relationship between the received data and the interrupt control signal (INT). However, the
delay from the actual received signal due to demodulation operations in MSK demodulation blocks is ignored.
Block synchronization is established by discriminating the BIC code. As shown in figure 3, the data for the nth packet
can be output during reception of the following packet (number n+1).
Figure 4 shows the output timing for post-vertical correction data. In vertical correction, the data for a single frame is
stored in memory and the correction operation is performed if frame synchronization was established and it was not
possible to correct all the packet data in horizontal correction. The timing with which vertical correction is started is the
start of the frame. Horizontal correction is performed for each packet while packets 1 through 28 in the nth frame are
being received, and this data is passed to the CPU interface. Vertical correction is performed for the data from the
previous frame (frame n-1) in the unused time periods during that processing.
The vertical correction data consists of 190 blocks that are output, and this data is output at the rate of one block for
every block received, in order starting at the time the 29th packet (block) is received. Only data from the data blocks in
the FM multiplex broadcast frame structure is output, and the last block (block 190) is output during reception of the
218th block.
As indicated previously (page 18) packet data that was, for example, corrected completely by horizontal correction, is not
output in the vertical correction output data. (The INT signal is not issued.) However, the order in which the horizontal
output is produced is not speeded up by the amount of the packet data that is not output. For example, if data packets 1 to
100 were corrected by horizontal correction, output of the post-vertical correction packet data for packet 101 will not
occur at the reception position of block number 29 in figure 4, but at the reception position for packet data number 129.
Packet n data
Packet n-1
Received
data
Packet n+1
BIC
BIC
18 ms
300 ns max
62.5 µs
BCK
300 ns max
INT
1 ms
Output period for
packet n+1 data
68 µs
Data cannot
be guaranteed
Packet n data output
Figure 3 Received Data, Block Synchronization, and Data Output Timing
First
frame
Received block
signal
271
272
nth frame
1
2
3
28
29
30
31
218
219
220
BCK
62.5 µs
FCK
18 ms
1
2
189
190
INT
1 ms
18 ms
18 ms × 28 = 504 ms
9 ms
9 ms
Output periods for
post-vertical correction
data from the prevoous
frame.
Figure 4 Post-Vertical Correction Data Output Timing
No. 6871-18/29
LC72714W
CPU Connection Example <Parallel Interface>
This section presents examples of the connection of this IC to a CPU.
Note that care is required with respect to read timing, since the time required to read a register, and the time required to
read a post-correction data packet (22 bytes) are different.
• Normal connection
When hardware waits are applied to the
CPU, the wait time (RDY width)
requires care.
BUSWD = low: 8 bits
BUSWD = high: 16 bits
LC72714W
CPU
D0 to D7
(D0 to D15)
A0 to A3
WR
WR
RD
CS
RD
CS
INT
INT
RDY
WAIT
DREQ
DACK
IOCNT1
IOCNT2
BUSWD
BUS-Width
8 bits
RST
PORT1
SP
• DMA transfer mode
I/O read/write operations are used for
the normal register read and write
operations. However, programmable
wait states may need to be inserted,
depending on the execution speeds.
DMA processing is only used for
readout of post-correction data.
Applications can select whether RD or
DACK is used as the DMA read control
signal by setting a register.
The default is to use the RD signal.
The data bus width in DMA mode is
always 8 bits.
LC72714W
CPU
D0 to D7
A0 to A3
WR
RD
CS
WR
INT
RDY
DREQ
DACK
INT
BUSWD
IOCNT1
IOCNT2
RST
CPU DMA mode setting example (For
reference only)
SH Series: Transfer type: 2-cycle
transfer
Transfer mode: Single
transfer mode
V Series: Address mode: Dual
address mode
Bus mode: Cycle
stealing mode
The source side (the FM multiplex IC)
address is fixed at 0.
RD
CS
DREQ
DACK
BUS-Width
8 bits
PORT1
SP
No. 6871-19/29
LC72714W
• Data bus I/O control block
The data bus (D0 to D15) can be controlled with two control signals: IOCNT1 and IOCNT2.
These pins must be held low if unused.
CS
IOCNT1
IOCNT2
RD
DACK
Control register 2, bits 1 and 2
D0 to D15
CPU Connection example <CCB Interface>
LC72714W
CPU
A1/CE
A0/CL
PORT1
SCK (*)
A2/DI
TX (*)
DO
RX (*)
INT
PORT2
(INT)
RST
PORT3
SP
* SCK, TX, and RX are the CPU serial interface channel. Normally, I/O port pins may be used for these lines.
* The resistance of the DO pin pull-up resistor must be selected according to the transfer clock speed.
No. 6871-20/29
LC72714W
Control Program Compatibility
This IC allows the majority of the control software used to be compatible with Sanyo’s other FM multiplex ICs, in
particular, the LC72700E, LC72705E, LC72706E, LC72708E, and LC72709E(W). However, the following aspects of
the control software require modification.
• Values of the register addresses
The addresses of the allowable BIC error count, synchronization error protection count, control registers, the layer 4
CRC register, and other registers have been modified.
The CCB address for serial I/O over a CCB bus has not been changed.
• INT signal output timing
The INT signal output timing for data output is as follows. A circle ("O") indicates that INT is output, and a cross ("X")
indicates that the signal is not output.
Item
Control
register 1
bit 5,
INT_MOVE
Control
register 2
bit 2,
VEC_OUT
Default value
L
L
Combination 1
H
Combination 2
Combination 3
Horizontal correction output
Operational overview
Vertical correction output
Correct
data
Incorrect
data
Parity
Correct
data
NG
Operation identical to that of the LC72705/06E and
LC72708/09E(W)
●
×
×
● *1
×
H
Operation identical to that of the LC72700E
All data is output
●
●
●
● *2
●
H
L
The output data selection conditions are cleared,
but there is no vertical correction output when
vertical correction is not performed
●
●
●
● *3
●
L
H
The output data selection conditions are retained,
but all of the vertical correction output is output
●
×
×
●
●
Notes:1. Data for which horizontal correction failed, but for which vertical correction succeeded is output.
2. All data is output.
3. If there is data for which horizontal correction failed, the post-vertical correction data for that data is output, regardless of whether or not vertical
correction succeeded.
(If the IC performs vertical correction, post-vertical correction data will be output.)
Notes on Output Data Selection after Tuning (Reference)
When building an FM multiplex reception system, a tuning system is an absolute necessity. However, if it is
unacceptable for the IC to output data from the old station after tuning to a new station, the application must perform the
following processing.
(1) At the same time as tuning a new station, the application must set bit 4 (SYNC_RST) in control register 1 to set the
synchronization circuit to the unsynchronized state.
(2) Under the default settings, after the synchronization reset applications must acquire data according to the issued INT
signal.
The post-vertical correction output is not provided by the IC until frame synchronization has been established for the
new station after tuning and the first vertical correction operation has been performed.
(3) If bit 2 (VEC_OUT) in control register 2 has been enabled, applications must not use the post-vertical correction
output (data for which bit 7 in the status register is high) until frame synchronization has been reestablished.
This IC performs the portion of the DARC FM multiplex processing through layer 2 error correction without requiring
any special control operations. The IC itself cannot determine if the contents of the received data have changed or if a
new station has been tuned. This means that applications must use the procedure described above for this IC not to output
old data and only output the new data. Another point is that in IC synchronization, although it is rare for the old station
and the new station to be frame synchronized, applications need to perform the processing in item 1 above to cancel
frame synchronization forward protection period.
No. 6871-21/29
LC72714W
Sample Data Acquisition Flowchart
Note: The figure below is for allocation of received data at the layer 3 level.
This documentation is present as an example for reference purposes only of FM multiplex data acquisition
processing by the system CPU. Its operation is not guaranteed.
INT
Status acquisition
Correction
complete?
** This discrimination is not required with the
default settings. (No INT signal is issued.)
Synchronized?
Read in the postcorrection data (22 bytes)
Was this
post-horizontal
correction data?
Prefix discrimination
Is the data
group complete?
YES
Prefix discrimination
Is the data
group complete?
YES
YES
Is the decoding
identifier 1?
YES
Start decoding and
presentation processing
Layer 4 CRC check
Start decoding and
presentation processing
Layer 4 CRC check
END
No. 6871-22/29
LC72714W
Prefix discrimination
YES
Is this the
data group for the
first reception?
Allocate a storage area
the size of the data group.
YES
Update the data in the
existing data storage area.
Update?
NO
Check the correctness of
the received data packet.
Resend?
YES
NO
Is the data
group complete?
Store in the corresponding
data group storage area.
YES
End
Additional Notes
In addition to the above processing, processing required for layer 3 (data group) level processing includes “deletion of
inappropriate data.” Although rare, in certain cases the IC will send inappropriate packet data that does not belong to any
data group currently being broadcast. The following three points are possible reasons for this occurring.
(1) The IC frame synchronization circuit generates an incorrect synchronization state, and the IC incorrectly outputs
parity packet data as normal packet data. This can occur when the back protection count is less rigorous (2 or lower),
or during weak field reception.
(2) While extremely rare, incorrect correction can occur. (This almost never happens.)
(3) Noise entering the data transfer lines between the FMD IC and the CPU within the end product set.
Inappropriate packet data that occurs for these reasons and does not belong to any data group, will not be updated, and
will remain in the program storage memory indefinitely. If the application does not include a routine that searches for and
deletes inappropriate data, program storage memory will overflow at some point.
Also, applications should perform a layer 4 CRC check after data group completion and before program display. There
are situations where the layer 4 CRC data is not present in the additional information. We recommend recognizing such
cases by judging in software at the layer 5 (segment) level whether or not the corresponding packet data is valid as an
addition information packet.
No. 6871-23/29
LC72714W
Notes on Simultaneous Reception of VICS and dGPS Data
Currently, VICS service data and dGPS service data are broadcast from different stations. Since the amount of the dGPS
data is small, 2 packets per frame, it is possible to receive both VICS data and dGPS data with a single tuner by
controlling the tuning of the receiver during the reception of mainly VICS data. During this operation, only the results of
horizontal error correction are used for dGPS data, and the VICS data that is missing due to the reception of dGPS data is
decoded (recovered) by using vertical direction error correction. (Caution: If there are any bad packets other than the
missing data, it may not be possible to recover the data.)
This IC includes functions that allow simultaneous acquisition of both VICS and dGPS data by controlling the tuning of a
single tuner. The following section describes the procedure for data reception using this function.
• Notes on block and frame synchronization
circuit operation
Normally, if the block synchronization system
issues an incorrect synchronization, the count
timing of the frame synchronization counter,
which is based on the block synchronization,
changes along with that error. If this state
continues for an extended period, the frame
synchronization circuit will take this new block
synchronization timing to be correct, and
discard the timing based on the original station
A. This is the situation that occurs during
normal tuning. That is, after the time for the
frame synchronization forward protection count
has passed, frame synchronization is lost, and
then after the time for the frame synchronization
back protection count has passed,
synchronization is established with a
synchronization timing that is different from
that of station A, which had been the prior
situation. Also, even if there is a block
synchronization error for a short period, the
temporary change in the block period can cause
a timing discrepancy in the frame
synchronization counter, which is based on the
block synchronization.
VICS data
dGPS data
Tuning
One frame
Frame phase
difference
Missing data
Figure 5 VICS and dGPS Data
This IC includes a compensation function to handle temporary incorrect synchronization in the block synchronization
circuit. What we are referring to as temporary incorrect synchronization in the block synchronization circuit is the
phenomenon shown in figure 6. Here, while the system is mainly receiving station A, the signal-to-noise ratio is
degraded for some reason and the circuit synchronizes with a timing that does not actually exist. After that, the circuit
resynchronizes with the block synchronization timing for the original station A due to, for example, improved reception
conditions. Even if such a condition occurs, the functions included in this IC allow it to actually acquire all the data that
can be acquired and furthermore, the synchronization circuit will not disrupt those conditions.
No. 6871-24/29
LC72714W
In figure 6, it is also possible to see the period
timing that caused the incorrect synchronization
with a timing other than that for station A to be
a sub-reception station completely separate from
station A, referred to here as station B. This IC
is thus able, in this manner, to acquire data from
both stations when the tuning is switched
between station A and station B without any
special control operations. In this case, it is
necessary for there to be temporary block
synchronization with station B, and this allows
us to apply this operation to the case of data
reception for VICS data (main station A) and
dGPS data (sub-station B). In figure 6, the
temporarily received data for station B can be
acquired as post-horizontal correction output
data, which is a real-time output, and the station
A data can be acquired as fully decoded data in
the post-vertical correction data.
Main
reception
station A
Incorrectly
synchronized
station
or
Sub-reception
station B
Figure 6 Main Reception Station and Sub-Reception Station
• Control method
This section presents an example of a possible flow of control.
First, the application detects the frame phase difference between the VICS station and the dGPS station, and then sets
the tuning control start timing based on that phase difference. The frame synchronization forward protection count is
set to at least 3, and the block synchronization back protection count is set to 2. Since BLK_RST, which only resets the
block synchronization circuit, is used, there is no need to modify the block synchronization forward protection count.
Note that these settings can be replaced by the default settings used by this IC.
When the BLK_RST is cleared after tuning the dGPS station, the IC starts block synchronization pull in, and after the
time corresponding to the block synchronization back protection count has passed, block synchronization with the dGPS
station data will be established. The post-horizontal correction output data (data for which status bit 7 (VH) is 0) that is
output from this point will be data received from the dGPS station.
After acquiring the stipulated number of packets of data, the application sets BLK_RST valid again, and tunes back to the
VICS station. If the dGPS station reception conditions are unluckily unfavorable, it will not be possible to establish block
synchronization, or it may not be possible to acquire fully corrected packet data. However, even if such conditions occur,
the receiver must tune back to the VICS station after receiving the stipulated number of packets of data. The reason is
that if the receiver did not do so, it would become impossible to completely decode the data in vertical correction for the
VICS station itself, which is the main station being received. Since the ability of vertical correction to correct burst errors
is about 10 packets, this sequence of tuning and data acquisition operations must completed within 10 packets. If that
condition is met, it will be possible to decode the VICS station data. However, this is only possible when there are no
packets that cannot be corrected other than those missed during the sequence of the simultaneous reception processing.
No. 6871-25/29
LC72714W
VICS - dGPS Reception
No
Is the timing
now that for dGPS
reception?
Yes
Set the frame forward protection count
to 3 or higher, set the block back
protection count to 2, and set the
allowable number of BIC errors to 1.
Control register 2 bits 6 and 7
BLKRST ← 1
SUBBLK ← 1
Tune the dGPS station
BLKRST ← 0
Acquire horizontal correction data
(3 or 4 packets)
BLKRST ← 1
Tune the VICS station
BLKRST ← 0
SUBBLK ← 0
Continue with normal data
reception processing.
No. 6871-26/29
LC72714W
Figure 7 shows the flow of the dGPS data reception sequence focusing on the block synchronization state. Block
synchronization is immediately set to the unsynchronized state by BLK_RST, and the IC then reacquires block
synchronization with the dGPS station. Of course, if the dGPS station reception conditions are unfavorable, time will
pass without acquiring block synchronization. In the example shown in this figure, the period during which VICS station
data cannot be acquired with horizontal correction processing is a 6-packet period. Since the ability of vertical correction
to correct burst errors is about 10 packets, this example has a margin of about 4 packets. This margin can be applied to
the period for establishing block synchronization with the dGPS station. That is, the best timing for tuning from the VICS
station to the dGPS station is about 4 packet positions before the position of the packet that has dGPS data.
Tuning the dGPS station
BLK RST
VICS station
block period
Missing
data 1
Tuning the VICS station
BLK RST
Missing
data 2
Missing
data 3
Missing
data 4
Missing
data 5
Missing
data 6
dGPS station
block period
Protection
count: 1
Protection
count: 2
dGPS data
IC block
synchronization
Post-horizontal
correction output
INT signal
OK
VCKS data
Bad
data
OK
data
OK dGPS
data
OK dGPS
data
Bad
data
Bad
data
Figure 7 VICS - dGPS Simultaneous Reception
• Notes
(1) The approach of using a single tuner for channel selection in the acquisition of both VICS and dGPS data, has
certain disadvantages from the standpoint of complete acquisition of the VICS data. This is because the VICS
station data transmitted while the tuner is tuned to the dGPS station will be handled as invalid data or bad packet
data. While the inherent vertical error correction capability is 10 to 12 bits, if we subtract the number of incorrect
VICS station packets during dGPS station reception, it is clear that this will seriously reduce the reliability of
recovery based on vertical error correction of the VICS data. This point must be taken into consideration.
(2) When using the control technique described above, the time allowed for dGPS data acquisition will be the time
required for about 10 packets. We recommend using the following synchronization system settings in order to
acquire the dGPS packet data within such a brief time. The reason the number of allowable BIC errors is changed
to a more strict value is to reduce the occasions where incorrect BICs are checked. However, even with these
settings, it may not be possible to lock synchronization with the set protection count if the reception conditions are
poor.
Default setting
Number of allowed BIC errors (backward)
2
Block synchronization error protection count (backward) 1
Frame synchronization error protection count (forward) 7
Recommended setting
1
1 (The default value can be used)
3 or higher (The default value can be used)
(3) Bit 7 in control register 2 (SUB BLK) must be set to 1 during dGPS data reception. If this flag is not set, decoding
for the VICS data vertical correction may not complete.
No. 6871-27/29
LC72714W
Sample Application Circuit (CCB serial interface)
INT
DO
A0/CL
A2/DI
A1/CE
STNBY
RST
CPU Interface
5 kΩ
3.3 µF
(*)
32
49
Analog GND
331
10 µF
FM composit
22 µH
LC72714W
(*)
561
22 µH
(*)
SQFP-64
64
1
16 pF
16
16 pF
+
–
This application circuit example can be used without change with any of the following ICs.
LC72710W, LC72710LW, LC72711W, LC72711LW, LC72713W, LC72714W
*: The information in this document is an example only, and the values shown are not guaranteed for use in the design of mass produced products.
Power supply pins
Pins 14, 15, 34, and 35: DRAM power supply
Pins 2 and 63: Digital system power supply
Pins 51 and 54: Analog system power supply
The RD, WR, CS, and DACK pins can also be handled by connecting them to ground.
*: The capacitors and coils marked with an asterisk (*) are used to isolate the analog and digital power supplies.
The technique used for separation shown here is presented for reference purposes, and may be modified if required.
No. 6871-28/29
LC72714W
• The DARC (Data Radio Channel) FM multiplex broadcast technology was
developed by NHK (Japan Broadcasting Corporation).
• DARC is a registered trademark of NHK Engineering Service (NHK-ES).
• A separate contract with NHK-ES is required in advance for the manufacture
and/or sale of electronic equipment that uses DARC technology.
• The logo shown here can be displayed on electronic equipment that uses DARC
technology.
• Sanyo Electric Co., Ltd. has reported to NHK-ES the number of units and purchasers of ICs that use DARC technology shipped
since October 1997.
Specifications of any and all SANYO products described or contained herein stipulate the performance,
characteristics, and functions of the described products in the independent state, and are not guarantees
of the performance, characteristics, and functions of the described products as mounted in the customer’s
products or equipment. To verify symptoms and states that cannot be evaluated in an independent device,
the customer should always evaluate and test devices mounted in the customer’s products or equipment.
SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all
semiconductor products fail with some probability. It is possible that these probabilistic failures could
give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire,
or that could cause damage to other property. When designing equipment, adopt safety measures so
that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective
circuits and error prevention circuits for safe design, redundant design, and structural design.
In the event that any or all SANYO products (including technical data, services) described or contained
herein are controlled under any of applicable local export control laws and regulations, such products must
not be exported without obtaining the export license from the authorities concerned in accordance with the
above law.
No part of this publication may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying and recording, or any information storage or retrieval system,
or otherwise, without the prior written permission of SANYO Electric Co., Ltd.
Any and all information described or contained herein are subject to change without notice due to
product/technology improvement, etc. When designing equipment, refer to the “Delivery Specification”
for the SANYO product that you intend to use.
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not
guaranteed for volume production. SANYO believes information herein is accurate and reliable, but
no guarantees are made or implied regarding its use or any infringements of intellectual property rights
or other rights of third parties.
This catalog provides information as of September, 2001. Specifications and information herein are
subject to change without notice.
PS No. 6871-29/29