HITACHI HD49235FS

HD49235FS
Digital Signal Processor for CD
ADE-207-162A(Z)
2nd. Edition
August 1995
Description
The HD49235FS is a digital signal processor for compact disc (CD) applications.
Features
• Powerful error correction capability: two-symbol C1 correction and four-symbol C2 correction
• Quadruple-speed reproduction supported (maintaining two-symbol C1 and four-symbol C2 error
correction)
• On-chip analog PLL and digital PLL (VCO and phase detector)
• Automatic adjustment of the free-running frequency of the VCO
• Built-in microprocessor interface
• On-chip 80-bit shift registers for Q-code buffering
• Cyclic redundancy check on Q-code values
• Audio output functions: monaural output, single-channel mute, left-right reverse, soft mute, –12-dB
attenuation
• 16-kbit RAM on-chip
HD49235FS
PDOUT1
VDD (A)
AMPP
AMPM
AMPO
AC
VSS (A)
PDOUT2
TEST1
MRST
PLLCK
NC
VDD (D)
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
Pin Arrangement
QDSEL
DSLCO
DSLCI
EFMI
DEFCT
TEST2
TEST3
UCKSL
VDD (D)
PWM
MON
MSTOP
PW64
ROTD
CLVS
SLOCK
64
65
41
40
80
25
24
XRST
CNIN
SENS
DATA
CLK
XLT
VSS (D)
OVFW
S1
QOK
QDATA
CKEXT
SUBOUT
SUBCK
CFCKP
EMP
BIDAT
MUTE
DAS
CKX
MPX
C2F
QMX
DMX
1
(Top view)
Rev.2, Aug. 1995, page 2 of 41
NC
NC
NC
NC
NC
NC
NC
NC
NC
VSS (D)
XCI
XCO
NC
MCK
TC1
UCK
HD49235FS
Pin Description
Pin
Polarity
No. Symbol
Name
I/O*
Connection
1
XRST
X (µ-com)
reset
I
Microprocessor Microprocessor interface
register reset
2
CNIN
Counter clock
input
I
Servo IC
3
SENS
Sensor
TO
Microprocessor Servo status output
4
DATA
Data
I
Microprocessor Data input for microprocessor
interface
5
CLK
Clock
I
Microprocessor Clock input for microprocessor
interface
6
XLT
X (µ-com) latch I
7
VSS (D)
VSS (digital)
H
8
OVFW
RAM- overflow O
9
S1
Subcode sync O
1
Microprocessor Subcode sync signal
(with protection)
10
QOK
Q-code OK
O
Microprocessor Subcode CRC result output
11
QDATA
Q-code data
O
Microprocessor Subcode Q data output
12
CKEXT
Clock-EXT
I
Microprocessor Clock input for Q data readout
13
SUBOUT Subcode out
O
CD graphics
Subcode data output for CD
graphics
14
SUBCK
Subcode clock I
CD graphics
Clock input for SUBOUT
subcode readout
15
CFCKP
C&D frame
clock out
O
CD graphics
Subcode frame
synchronization signal (7.35
kHz at normal speed,
synchronized with PLL)
16
EMP
Emphasis
output
O
Emphasis on/off status output ON
17
BIDAT
Biphase date
TO
Digital audio interface output
18
MUTE
Mute
I
19
DAS
Data serial out O
DAC or ROM
decoder
Serial data output for audio or
ROM
20
CKX
Clock X
DAC or ROM
decoder
Strobe clock output for DAS
signal
L
Reset
Pulse input for track counter
Microprocessor Strobe input for
microprocessor interface
—
O
Function
Digital ground
On-chip RAM overflow signal
output
Microprocessor Audio mute input
Overflow
OK
NG
OFF
Mute
Rev.2, Aug. 1995, page 3 of 41
HD49235FS
Pin Description (cont)
Pin
Polarity
No. Symbol
Name
I/O*
Connection
Function
21
MPX
Multiplex
O
DAC or ROM
decoder
Left/right channel switching
signal output (44.1 kHz at
normal speed, synchronized
with DAS)
22
C2F
C2 flag
O
ROM decoder
C2 error flag output
23
QMX
Quad multiplex O
4 × MPX clock signal
(176.4 kHz at normal speed,
synchronized with DAS)
24
DMX
Double
multiplex
O
2 × MPX clock signal
(88.2 kHz at normal speed,
synchronized with DAS)
25
UCK
µ-com clock
O
26
TC1
Test C1 flag
O
C1 error flag monitor pin
27
MCK
Master clock
O
Master clock output
(33.8688 MHz)
28
NC
No connection —
Open or VDD
Not connected
29
XCO
X’tal clock
output
XO
Crystal
oscillator
Crystal oscillator output
30
XCI
X’tal clock
input
XI
Crystal
oscillator
Crystal oscillator input
31
VSS (D)
VSS (digital)
—
32
NC
No connection —
Open
Not connected
33
NC
No connection —
Open
Not connected
34
NC
No connection —
Open
Not connected
35
NC
No connection —
Open
Not connected
36
NC
No connection —
Open
Not connected
37
NC
No connection —
Open
Not connected
38
NC
No connection —
Open
Not connected
39
NC
No connection —
Open
Not connected
40
NC
No connection —
Open
Not connected
41
NC
No connection —
Open
Not connected
42
NC
No connection —
Open
Not connected
43
NC
No connection —
Open
Not connected
44
NC
No connection —
Open
Not connected
Rev.2, Aug. 1995, page 4 of 41
H
L
Error
Microprocessor Clock output for
microprocessor
(8.5 MHz or 17 MHz)
Digital ground
Error
HD49235FS
Pin Description (cont)
Pin
Polarity
No. Symbol
Name
45
NC
46
I/O*
Connection
Function
No connection —
Open
Not connected
NC
No connection —
Open
Not connected
47
NC
No connection —
Open
Not connected
48
NC
No connection —
Open
Not connected
49
NC
No connection —
Open
Not connected
50
NC
No connection —
Open
Not connected
51
NC
No connection —
Open
Not connected
52
VDD (D)
VDD (digital)
53
NC
No connection —
54
PLLCK
PLL clock
O
55
MRST
Master reset
IU
Open or VDD
Master reset of chip
56
TEST1
TEST 1
IU
Open or VDD
Test pin
57
PDOUT2 Phase detect
out 2
TO
External RC
circuit
PLL auto-adjust phase
detector output
58
VSS (A)
VSS (analog)
—
59
AC
Amp
compensation
A
External RC
circuit
Amplifier phase compensation
pin
60
AMPO
Amp output
AO
External RC
circuit
PLL amplifier output
61
AMPM
Amp minus
input
AI
External RC
circuit
PLL amplifier inverting input
62
AMPP
Amp plus input AI
External RC
circuit
PLL amplifier non-inverting
input
63
VDD (A)
VDD (analog)
64
PDOUT1 Phase detect
out 1
TO
65
QDSEL
Q-data clock
select
IU
66
DSLCO
DSL control
output
O
External RC
circuit
EFM comparator slice level
control output
67
DSLCI
DSL control
input
AI
External RC
circuit
EFM comparator slice level
control input
68
EFMI
EFM signal
input
AI
69
DEFCT
Defect
I
Servo IC
Defect detection signal input
70
TEST2
TEST 2
IU
Open or VDD
Test pin
—
H
L
Digital power supply
Open or VDD
Not connected
PLL clock output monitor
Reset
Analog ground
—
Analog power supply
External RC
circuit
PLL EFM phase detector
output
Q data readout mode
switching signal input
Internal
sync
External
sync
EFM signal input
Defect
Rev.2, Aug. 1995, page 5 of 41
HD49235FS
Pin Description (cont)
Pin
Polarity
No. Symbol
Name
I/O*
Connection
Function
H
71
TEST3
TEST 3
IU
Open or VDD
Test pin
72
UCKSL
Microcomputer IU
clock selection
Microprocessor clock
switching signal input
73
VDD (D)
VDD (digital)
—
Digital power supply
74
PWM
Pulse width
modulate
TO
Constant linear velocity (CLV)
control signal for disc motor
75
MON
Motor on
O
Disc-motor-on status detection On
output
76
MSTOP
Motor stop
TO
CLV phase control signal
77
PW64
Pulse width
64T
O
Microprocessor Brake release signal
78
ROTD
Rotate
direction
O
Microprocessor MSB of PWM pin output, for
monitoring
79
CLVS
CLV status
O
Microprocessor Output indicating normal or
starting mode of CLV control
80
SLOCK
Sync lock
O
Microprocessor Disc motor rotation lock signal Lock
L
16.9344 8.4672
MHz
MHz
Normal
Starting
Note: * I—input; O—output; IO—input/output; IU—pulled-up input; TO—three-state output; A—analog pin;
AI—analog input; AO—analog output; XI—oscillator input; XO—oscillator output
Rev.2, Aug. 1995, page 6 of 41
HD49235FS
DSLCO
DSLCI
EFMI
DEFCT
MCK
UCK
UCKSL
PWM
MON
MSTOP
PW64
CLVS
ROTD
Block Diagram
79 78 77 76 75 74
72 25 27 69 68 67 66
CLV servo control
Cmp
64 PDOUT1
62 AMPP
SLOCK 80
EFM
demodulation
Sync protection
XRST 1
CNIN 2
SENS 3
Data strobe
61 AMPM
+-
59 AC
60 AMPO
VCO
Microprocessor
interface
DATA 4
CLK 5
Freq. Div.
57 PDOUT2
54 PLLCK
XLT 6
Error correction unit
(ECU)
QDSEL 65
S1 9
QOK 10
QDATA 11
CKEXT 12
Subcode signal
processing
SUBOUT 13
SUBCK 14
26 TC1
16 k SRAM
Data bus
8 OVFW
CFCKP 15
EMP 16
RAM control
BIDAT 17
Digital output
MUTE 18
DAS 19
CKX 20
MPX 21
C2F 22
Interpolation
24
DMX
MRST
23
QMX
XCI
70 71
TEST3
55 56
TEST2
30
TEST1
29
XCO
Timing
generator
Rev.2, Aug. 1995, page 7 of 41
HD49235FS
Microprocessor Commands
Data
D4
D3
D2
D1
D0
SENS
Pin
Output
ROMEF DOOFF
SUBCO
SLTSW
0
DCOND
DWIDTH
Z
1
BI1
BI0
WG10TL SYLCK1
*
Z
Audio
control
MUTEL
MUTER
MONO
ATT
BLGMAIN BLGSUB SOFTMT SWLR
Z
B (1011)
Track
counter
setting
TC7
TC6
TC5
TC4
TC3
TC2
Complete
C (1100)
CLV control AINTV
ATH
GAIN1
GAIN0
SGAIN1
SGAIN0 PDGAIN1 PDGAIN0 Count
D (1101)
CLV kick
control
KICK7
KICK6
KICK5
KICK4
KICK3
KICK2
KICK1
*
Z
E (1110)
CLV mode
ED3
ED2
ED1
ED0
0
*
*
*
BRAKE
F (1111)
ECU mode
0
0
AS0
*
*
*
*
*
Z
Register
(Address) Command
D7
D6
8 (1000)
Mode
selections
ROM
9 (1001)
Function
selections
A (1010)
D5
SYLCK0 CRCQ
TC1
TC0
Asterisks indicate don’t-care bits
Register 8
ROM
D7
0
1
Audio (with interpolation)
CD-ROM (no interpolation)
ROMEF
D6
C2 flag output order: lower first
C2 flag output order: upper first
DOOFF
D5
Digital output on
Digital output off
SUBCO
D4
Subcode data not inserted in DAS signal
Subcode data inserted in DAS signal
SLTSW
D3
48-fs clock
64-fs clock
D2
Normal operation
Illegal setting
DCOND
D1
Condition for switching between digital and Condition for switching between digital and
analog PLLs: digital PLL when defect
analog PLLs: digital PLL when defect
detection signal width is 4 frames or more detection signal width is 8 frames or more
DWIDTH
D0
Digital PLL termination timing:
•
•
8 frames after fall of defect detection
signal if width of defect detection signal
width is less than 12 frames
4 frames after fall of defect detection
signal if width of defect detection signal
width is less than 12 frames
•
16 frames after fall of defect detection •
signal if width of defect detection signal
width is 12 frames or more
8 frames after fall of defect detection
signal if width of defect detection signal
width is 12 frames or more
Rev.2, Aug. 1995, page 8 of 41
HD49235FS
Register 9
0
1
D7
Illegal setting
Normal operation
BI1
D6
00: Normal play
01: Double-speed play
BI0
D5
10: Quadruple-speed play
11: Quadruple-speed play
WG10TL
D4
Sync detection window width: ±10 T
SYLCK1
D3
Length of time sync lock state is maintained when sync signal is missing
SYLCK0
D2
CRCQ
D1
00: 2 frames
01: 4 frames
10: 8 frames
11: 12 frames
Sync detection window width: ±19 T
QOK flag is not inserted in QDATA output QOK flag is inserted in QDATA output
Register A
0
1
MUTEL
D7
Left-channel mute off
Left-channel mute on
MUTER
D6
Right-channel mute off
Right-channel mute on
MONO
D5
Stereo
Monaural
ATT
D4
Attenuation off
Attenuation (–12 dB) on
BLGMAIN
D3
00: Stereo
01: Bilingual, right channel
BLGSUB
D2
10: Bilingual, left channel
11: Bilingual, left channel
SOFTMT
D1
Soft mute off
Soft mute on
SWLR
D0
Normal
Left-right reverse
Notes: 1. Priority for mute and attenation as follows.
“Mute” port > SOFTMT > MUTE L, MUTE R > ATT
2. In the case of setting “ROM” = 1 (CD-ROM mode), the data of register “A” is ignored and is
considered all zero.
It is recovered as it were, after setting “ROM” = 0.
3. “BLGMAIN” and “BLG SUB” commands are ignored if “SWLR” = 1, and set stereo.
Register B
Track counter setting
D7
D6
D5
D4
D3
D2
D1
D0
TC7
TC6
TC5
TC4
TC3
TC2
TC1
TC0
128
64
32
16
8
4
2
1
Rev.2, Aug. 1995, page 9 of 41
HD49235FS
Register C
0
1
AINTV
D7
Sync detection count is tested at 32-frame Sync detection count is tested at 64-frame
intervals
intervals
ATH
D6
Sync must be detected 4 times or more
GAIN1
D5
Speed error (PWM pin output) gain in CLV steady state operation
GAIN0
D4
00: –6 dB
01: 0 dB
10: +6 dB
11: 0 dB
SGAIN1
D3
SGAIN0
D2
Sync must be detected 8 times or more
Speed error gain and access
00: –6 dB
01: 0 dB
10: +6 dB
11: 0 dB
PDGAIN1
D1
CLV phase error (MSTOP pin output) gain
PDGAIN0
D0
00: –6 dB
01: 0 dB
10: +6 dB
11: 0 dB
Register D
D7
D6
D5
D4
D3
D2
D1
D0
CLV kick control
KICK7
KICK6
KICK5
KICK4
KICK3
KICK2
KICK1
*
(PWM duty cycle)
64/128
32/128
16/128
8/128
4/128
2/128
1/128
*
Asterisks indicate don’t-care bits
Rev.2, Aug. 1995, page 10 of 41
HD49235FS
CLV Mode (Register E)
ED3 to ED0/HEX
Mode
Status
0000
0
STOP
Motor stop
0110
6
PLAY
Starting mode
Normal mode
1000
8
ROT
Disc motor driven forward
1001
9
KICK
Kick control
1010
A
BRAKE
Disc motor driven in reverse
1100
C
ACS
Access mode
1110
E
START
Forced starting mode
1111
F
NORM
Forced normal mode
AS0
Mode
Status
0
FULL
Error correction: C1—two symbols; C2—four symbols
1
E4IHD
C2—four symbol error correction inhibited on track jump
ECU Mode (Register F)
Rev.2, Aug. 1995, page 11 of 41
HD49235FS
Functional Description
Data Strobe
The main functions of this block are described below.
1. Generation of Basic Crystal Clock
XCI: Is the inverter input pin for the crystal oscillator.
XCO: Is the inverter output pin for the crystal oscillator.
A 33.8688-MHz crystal oscillator clock signal is generated at the XCI and XCO pins. Figure 1 shows
the standard external components when a 33.8688-MHz crystal is used.
2. Generation of Basic PLL Clock
PLLCK: This is an output pin used for monitoring the VCO oscillator signal. When the PLL is in lock,
the frequency is 4.3218 MHz at standard speed, 8.6436 MHz at double speed, or 17.2872 MHz at
quadruple speed.
PDOUT1: This is a phase detector output pin, for use in data strobing. This pin is in the highimpedance state in the CLV stop mode. In other CLV modes, this pin outputs the result of phase
detection in a phase-locked loop formed with the VCO and the EFM signal input at the EFMI pin.
PDOUT2: This is a phase detector output pin, for use in adjusting the free-running frequency of the
VCO. In CLV stop mode, this pin outputs a pulse-width modulated waveform equivalent to the phase
error in a phase-locked loop formed with the VCO and a crystal-oscillator-derived clock signal. In other
CLV modes, this pin maintains a pulse-width modulated output with the same duty cycle as in stop
mode.
AC: Connect a capacitor for phase compensation of the amplifier.
AMPO: Amplifier output pin.
AMPM: Inverting input to the amplifier.
XCI
XCO
30
29
1 MΩ
3.3 µH
100 pF
15 pF
15 pF
Figure 1 33.8688-MHz Crystal Oscillator Circuit
Rev.2, Aug. 1995, page 12 of 41
HD49235FS
AMPP: Non-inverting input to the amplifier.
This chip uses a PLL for recovery of the bit clock. A built-in circuit automatically adjusts the freerunning frequency of the PLL, so fewer adjustments are required on the production line. The chip can
be forced to adjust its own free-running frequency whenever power is turned on or the speed is changed
by switching to CLV stop mode. Thus the free-running frequency is always set to the center of the lock
frequency range even if changes occur in the VCO and external circuit constants due to aging.
The principle and usage of automatic adjustment of the free-running frequency will be described below.
a. In automatic adjustment of the VCO free-running frequency, this chip uses the disc stop signal. The
disc stop signal is turned on when the microprocessor writes 0000 in bits ED3, ED2, ED1, and ED0
of register E in the chip’s microprocessor interface. (See section 6, Microprocessor Interface.)
b. When the disc stop signal is turned on, counter (A) in figure 2 becomes a divide-by-98 counter,
switch (A) is connected to the output from the VCO, and switch (B) is connected to digital 0.
At this time, the circuit for the PDOUT1 output is stopped, so the output of the LPF1 connected to
PDOUT1 goes to the fixed DC bias level, which is 1/2 VDD.
The loop formed by PDOUT2 → LPF2 → amplifier → VCO → counter (A) now operates to lock
the VCO oscillator frequency to 34.5744 MHz, which is 8 times the standard CD bit rate (4.3218
MHz).
Rev.2, Aug. 1995, page 13 of 41
HD49235FS
SW B
EFM signal
Phase
detector 1
LPF1
3.3 kΩ
64
Digital 0
PDOUT1
3.3 kΩ
Disc stop
signal
62
61
+
–
59
60
AMPP
AMPM
AC
AMPO
VCO
×1 speed, ×2 speed,
×4 speed Playback
speed select signal
4.2336 / 8.4672 / 16.9344 MHz
derived from
crystal oscillator clock
34.5744 MHz
SW A
55 PLLCK
4.3218 / 8.6436 / 17.2872 MHz
Disc stop
signal
Automatic
adjustment
loop of the
free-running
frequency
1/8, 1/4, 1/2
frequency
division
1/98 or 1/96
frequency Counter A
division
44.1 / 88.2 / 176.4 kHz
44.1 / 88.2 / 176.4 kHz
derived from
crystal oscillator clock
10 kΩ
LPF2
57
PDOUT2
10 kΩ
Phase
detector 2
Note: When changing the playback speed, always switch the system to CLV stop mode so that the freerunning frequency is adjusted automatically. The period of setting is 30 msec or more.
Within five second after turning on power, switch the sytem to CLV stop mode two times or more
in an interval from one to two second so that the free-running frequency is adjusted automatically.
The period of setting is 30 msec or more.
Figure 2
Rev.2, Aug. 1995, page 14 of 41
HD49235FS
c. Next, reproduction from the disc will begin. When the microprocessor sends command data to start
disc rotation, the disc stop signal is turned off.
Switch (A) is now connected to receive a 4.2336 MHz clock from the crystal oscillator and counter
(A) is changed to be a divide-by-96 counter. The counter (A) output is held at 44.1 kHz by
switching the divisor. Here, switching is performed on the counter (A) output edge. The phase error
existing between the VCO and the crystal oscillator clock (the phase error that was detected at
adjustment step 2) is maintained.
d. When the disc is rotating and reproduction starts, switch (B) is connected to receive the EFM signal.
The phase detector PDOUT1 in figure 2 compares the phases of the EFM signal, which was
converted to binary by the EFM comparator, and the bit clock and outputs phase comparison
information from the PDOUT1 pin.
As shown in figure 3, when the EFM signal is in phase with the clock produced by the VCO, the
PDOUT1 output is high and low for equal lengths of time. When the EFM signal leads the on-chip
VCO clock, the high length is longer than the low length. When the EFM signal lags the on-chip
VCO clock, the high length is shorter.
(In phase)
EFMI
Bit clock
PDOUT1
High impedance
(Phase leads)
EFMI
Bit clock
PDOUT1
High impedance
(Phase lags)
EFMI
Bit clock
PDOUT1
High impedance
Figure 3 Timing of PDOUT1 Output Signal
Rev.2, Aug. 1995, page 15 of 41
HD49235FS
3. Data Slice Level Output
EFMI: This pin inputs the EFM RF signal.
DSLCO: This pin outputs an error signal for correcting deviation in the data slice level of the EFM
signal. This signal is used as a control signal to keep the data slice level of the EFM signal centered, by
forming a negative-feedback loop with the EFM comparator.
DSLCI: This pin inputs the above error signal through a low-pass filter to the EFM comparator.
Figure 4 shows the EFM comparator circuit. The EFM RF signal is input through a capacitive coupling,
and binarized by comparison with a slice level generated by the DSLC amplifier.
 When not in stop mode
 The DSLCO pin outputs the inverse of the binarized EFM signal. Even if the EFM signal is
asymmetrical before slicing, an appropriate slice level is obtained by feeding the dc component of
the sliced EFM signal back through an external low-pass RC filter.
 In stop mode
 The DSLCO pin outputs a square wave with a 50% duty cycle and the same period as the output at
the MPX pin, and the slice level is kept at 1/2 VDD. This permits rapid optimization of the slice level
when the device leaves stop mode, and prevents oscillation by cutting off the loop through the lowpass filter.
4. Control When a Defect is Detected
DEFCT: This pin inputs a disc defect detection signal. Both a digital PLL and an analog PLL are
provided on-chip. Normally the analog PLL is used, because of its good error-rate characteristic, but
when a defect detection signal is received at this pin, the chip switches over to its digital PLL for quick
pull-in after the defect disappears. After pull-in, the chip automatically switches back to its analog PLL.
UCK: This pin outputs a clock signal for the microprocessor.
UCKSL: This pin selects the frequency of the microprocessor clock (UCK). The frequency is 16.9344
MHz when UCKSL is high, and 8.4672 MHz when UCKSL is low.
MCK: This pin outputs the master clock (33.8688 MHz).
STOP
DSLCO
66
LPF
1/2 VDD
67
DSLCI
MPX
×1 ×2 ×4 speed
44.1/88.2/176.4 kHz
DSLC amplifier
–
Amp.
+
–
Comp.
+
EFM comparator
68
EFM
RF signal
EFMI
Figure 4 EFM Comparator Circuit
Rev.2, Aug. 1995, page 16 of 41
To internal circuits
EFMS
STOP
HD49235FS
EFM Demodulation
After being processed in the data strobe block, the EFM signal is converted to NRZ by an NRZ-I
conversion using a PLL-synchronized clock signal (PLL clock, 4.3218 MHz when the PLL is locked in
standard speed playback mode).
The 24-bit frame synchronization signal is detected from this EFM signal. Operation of the EFM
demodulation block is timed according to the occurrence of the frame synchronization signal.
Due to disc defects and other causes, frame synchronization signals may sometimes be detected at false
positions in the EFM signal read from the disc. The sync protection block therefore opens a window around
the time when the correct synchronization signal is expected, and frame synchronization signals are used
for timing purposes only if they are detected within this window.
If the frame synchronization signal is not detected, it is automatically interpolated at the time when the
correct frame synchronization signal would be expected to occur. Detection and interpolation of the frame
synchronization signal will be described in detail in the description of the sync protection block.
After being converted to NRZ form, the EFM signal is converted to 14-bit parallel data by the EFM
demodulation block. This conversion is timed to the occurrence of the above frame synchronization signal.
Next, 14-bit-to-8-bit demodulation is performed: the 14-bit parallel data is fed to the EFM demodulation
ROM and converted to 8 bits.
After EFM demodulation, the 8-bit data is separated into subcode data, which is passed to the subcode
signal-processing block, and audio data, which is output to the internal data bus. The data bus is connected
to the error correction unit (ECU) and the RAM control block.
Subcode Signal Processing
S1: The CD format groups subcode data into 98-frame blocks. Each block begins with two subcode
synchronization signals: S0 and S1. In this chip, S0 and S1 are detected in the EFM demodulation
block. S0 is delayed by one frame, then ANDed with S1, and the result (S0delay⋅S1) is output at the S1
pin.
Due to disc defects and other causes, the above S0 and S1 signals may sometimes fail to be detected.
The chip accordingly has a divide-by-98 counter that takes S0delay⋅S1 as its clear input and CFCKP* as
its clock input. When S0delay⋅S1 is not detected, it is interpolated by this counter. See figure 5.
Note: * CFCKP is derived from the PLL clock and has a frequency of 7.35 kHz (×1 speed), 14.7 kHz (×2
speed), 29.4 kHz (×4 speed) when the PLL is in lock.
Rev.2, Aug. 1995, page 17 of 41
HD49235FS
S0
D
S0 delay · S1
Q
S1 output pin
S1
"97"
Interpolated S1 signal
Decoder
Clear
Divide-by-98 counter
CFCKP
Figure 5 Block Diagram of S1 Signal Detection Circuit
Rev.2, Aug. 1995, page 18 of 41
HD49235FS
QDATA: This is the output pin for the Q subcode data.
QDSEL: This pin selects one of the following two modes.
a. Q code buffer mode (selected when QDSEL is low)
When the QDSEL pin is low, the chip uses its 80-bit Q code buffer function, and outputs the Q
subcode from the QDATA pin in synchronization with an external clock signal (for example, a
clock signal from a microprocessor).
As shown in figure 6, the chip has two 80-bit registers. While Q code data is being written in one
register, the Q code can be read from the other register asynchronously, by input of clock signals
from the microprocessor at the CKEXT pin. This feature places less of a load on the microprocessor.
To switch between reading and writing of the shift registers, the S1 and QOK signals are ANDed, so
before sending clock pulses for input to CKEXT, the microprocessor should check for the fall of S1,
then check that QOK is high (indicating that the cyclic redundancy check of the Q data passed).
These checks will enable the Q subcode to be read correctly.
The 80-bit shift register is designed to store data in 4-bit nibbles, LSB first. If the microprocessor
inputs serial data in LSB-first form, it does not have to rearrange the 4 bits.
Figure 7 shows the timing chart.
b. Q code internal synchronization mode (selected when QDSEL is high)
When the QDSEL pin is high, a Q code strobe clock generated in the HD49235 is output from the
CFCKP pin, and the Q code is output from the QDATA pin at a rate of one bit per frame,
synchronized with the strobe clock (CFCKP). This is referred to as Q code internal synchronization
mode. Figure 8 shows the timing.
S1 · QOK
Subcode
Q
4-bit
rearrangement
CK
80-bit shift register
QDATA
80-bit shift register
CK
CKEXT
Figure 6 Block Diagram of Q Code Buffer When QDSEL is Low
Rev.2, Aug. 1995, page 19 of 41
HD49235FS
QOK: The output at this pin indicates whether or not the Q subcode is correct.
One block of Q subcode data consists of 98 bits, of which 16 bits are parity bits that indicate whether
the data read from the disc was correct or in error. An on-chip cyclic redundancy check circuit decides
whether the 98-bit data string is correct or not, and outputs the result at the QOK pin. A high-level
output indicates OK. Figures 7 and 8 show the output timing.
In modes using the Q code buffer register, when the microprocessor sets the CRCQ bit to 1, QOK is
inserted in QDATA at the rise of S1.
See the note in the timing chart shown in figure 7.
EMP: This output pin indicates the presence or absence of pre-emphasis. The pre-emphasis signal is
detected from the Q subcode and output at the EMP pin. High output indicates audio with pre-emphasis.
Low output indicates audio without
pre-emphasis.
SUBOUT: This pin outputs codes R to W for use in display of graphics.
CFCKP: This pin outputs a subcode frame synchronization signal.
S1
QOK
1
2
3
4
5
Q4
Q3
Q2
Q1
Q8
80
1
2
3
Q4
Q3
Q2
CKEXT
QDATA
*
Q77
*
Note: * Undefined when CRCQ = 0; QOK when CRCQ = 1 (high when CRC result is OK)
Figure 7 Timing When QDSEL is Low (Q Code Buffer Mode)
CKEXT
7.35 kHz
CFCKP
QDATA
Q96
S0
S1
Q1
S1
QOK
CRC result data: high when OK
Figure 8 Timing When QDSEL is High(Q Code Internal Synchronization Mode,
Standard Speed Playback)
Rev.2, Aug. 1995, page 20 of 41
HD49235FS
SUBCK: This pin inputs a subcode read clock.
Codes R to W are output together with codes P and Q. The codes are output in order, starting with the P
code, as serial data from the SUBOUT pin when read clock pulses are input at the SUBCK pin. Figure 9
shows the timing, which basically conforms to EIAJ CP-2401.
Signal Configuration: Figure 9 shows the signals output for use in display of graphics. (SF: subcode
frame)
To read the subcode data, eight subcode clock pulses (SUBCK) should be input after the fall of the
subcode frame synchronization signal (CFCKP). The data for subcode channel P is output at the fall of
CFCKP. Data in channels Q to W is output at the rise of SUBCK. See figure 10.
SF0
SF1
SF2
SF3
SF4
SF97
SF0
*
*
*
*
*
*
S1
CFCKP
SUBCK
SUB
OUT
P to W
P to W
P to W
Notes: Segments marked with X's are don't-care segments.
* SUBCK input during SF0 and SF1 is permissible, but the resulting output from SUBOUT
will not necessarily be correct.
Figure 9 Output Timing for Graphics Display (1)
Subcode frame (SF)
CFCKP
SUBCK
SUB
OUT
P
Q
R
S
T
U
V
W
P
Figure 10 Output Timing for Graphics Display (2)
Rev.2, Aug. 1995, page 21 of 41
HD49235FS
Control of 16-kbit On-Chip SRAM
The demodulated EFM data is synchronized with the PLL clock, and its output timing may contain jitter
due to disturbances in the CLV servo that controls disc rotation. To absorb the jitter, the demodulated EFM
data is stored in the on-chip RAM, then read out in synchronization with a clock signal derived from the
crystal oscillator. The RAM capacity sets a limit on the amount of jitter that can be absorbed. In this chip, a
delay of ±5 frames between RAM read and write would lead to overwriting of existing data. The
overwritten data would be destroyed, making the reproduced sound unreliable.
To avoid this, if the read and write base counters get more than ±5 frames out of step, the write base
counter is set to the value of the read base counter and the frame jitter margin is set to the maximum, ±5
frames.
OVFW: This pin outputs a high RAM overflow flag signal to indicate that the difference between the
read and write base counters exceeded ±5 frames and the write base counter was set to the value of the
read base counter.
MUTE: This pin is used to force the audio data to the mute state.
When MUTE is low, muting is not performed.
When MUTE is high, muting is performed.
When MUTE goes high, the address control circuit is initialized so as to maximize the RAM frame jitter
margin at that point. This initialization is performed continuously while MUTE is high. Normal
reproduction resumes when MUTE goes low.
Error Correction Unit (ECU)
The error correction unit can correct two-symbol C1 errors and four-symbol C2 errors.
The results of C1 error correction are flagged by a C1 flag. Since two-symbol errors can be corrected, each
C1 correction produces a 2-bit C1 flag. The C1 flag data is written into an internal buffer RAM area and is
read out again during C2 correction.
C2 error correction is carried out using the calculated error locations and error values, and the C1 error
status and error positions indicated by the C1 error flags.
The interpolation block reads audio data and the corresponding C1 and C2 flags. If it decides from the C1
and C2 flags that the audio data is unreliable, it performs mean-value interpolation or preceding-value
interpolation.
TC1: This pin outputs a signal indicating whether each frame of data read from the disc contained an
error. See figure 11 for the output timing.
High if no error
TC1
136 µs
354 ns
Figure 11 TC1 Timing (Standard Speed Playback)
Rev.2, Aug. 1995, page 22 of 41
HD49235FS
Microprocessor Interface
DATA: Input pin for receiving microprocessor command data.
CLK: Clock input pin for receiving microprocessor command data.
XLT: Latch clock input pin for storing microprocessor command data in an internal register after serial
input.
XRST: Input pin for clearing the microprocessor command registers.
SENS: This output pin provides the microprocessor with the following servo information. For details,
see the microprocessor command descriptions.
 The SENS signal goes low when the number of pulses input at the CNIN pin reaches a value set by
the microprocessor. Alternatively, SENS toggles between low and high each time this value is
reached.
 When the constant linear velocity (CLV) servo operates in brake mode, SENS goes low to indicate
detection of an interval of 32 T or more. This indicates that braking has operated and the velocity
has fallen to 1/3 or less.
CNIN: This pin receives track-crossing pulses from the servo IC, so that the number of tracks can be
counted.
1. Data Transfer Format
The microprocessor interface transfers serial data using three signal lines: XLT, CLK, and DATA. See
the timing diagram in figure 12. D11 to D8 specify a register address and D7 to D0 give bit values to be
set in that register.
Notes: 1. When the external reset input signal (XRST) goes low all registers are reset to their default
values. See table 1.
2. Always write 0 in the following register bits:
D2 in register 8
D3 in register E
D7 and D6 in register F
3. Always write 1 in the following register bit:
D7 in register 9
Table 1
Default Values
Register Code
D7
D6
D5
D4
D3
D2
D1
D0
8 (1000)
0
0
0
0
0
0
0
0
9 (1001)
1
0
0
0
1
1
0
A (1010)
0
0
0
0
0
0
0
0
B (1011)
0
0
0
0
0
0
0
0
C (1100)
1
1
1
0
0
0
0
1
D (1101)
0
0
0
0
0
0
0
E (1110)
0
0
0
0
0
F (1111)
0
0
0
Rev.2, Aug. 1995, page 23 of 41
HD49235FS
DATA
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9 D10
D11
CLK
XLT
Figure 12 Microprocessor Interface Timing
2. Microprocessor Commands
These commands are summarized in the microprocessor command tables. Further details and notes are
given below.
a. Mode Selections (Register 8)
ROM: This bit controls whether or not interpolation is performed on audio data output from DAS.
When ROM = 0, interpolation is performed (for audio applications).
When ROM = 1, interpolation is not performed (for CD-ROM applications).
ROMEF: When ROM = 1 (for CD-ROM applications), the upper and lower C2 flag data is output in
two 8-bit segments. ROMEF selects which is output first: the upper or lower data.
When ROMEF = 0, the lower data is output first.
When ROMEF = 1, the upper data is output first.
DOOFF: This bit switches the digital audio interface output from pin 17 (BIDAT) on or off.
When DOOFF = 0, a signal is output.
When DOOFF = 1, the BIDAT pin is in the high-impedance state.
SUBCO: This bit selects whether to insert subcode data in the DAS output on the DAC output interface
(MPX, CKX, DAS) in 48fs clock mode (when microprocessor command bit SLTSW is 0).
When SUBCO = 0, subcode data is not inserted.
When SUBCO = 1, subcode data is inserted.
SLTSW: This bit selects 48fs clock mode or 64fs clock mode for the DAS output.
When SLTSW = 0, DAS data is output in 48fs clock mode.
When SLTSW = 1, DAS data is output in 64fs clock mode.
DCOND: This bit selects the condition for switching from the analog PLL to the digital PLL when a
defect is detected, in terms of the width of the defect detection signal input at the DEFCT pin (pin 69).
When DCOND = 0, the width must be at least four frames.
When DCOND = 1, the width must be at least eight frames.
DEFCT (defect
detection signal)
Set by DCOND
PLL
Analog
Set by DWIDTH
Digital
Figure 13 PLL Modes when a Defect is Detected
Rev.2, Aug. 1995, page 24 of 41
Analog
HD49235FS
DWIDTH: This bit selects the interval from the high-to-low transition of the defect detection signal
until termination of the digital PLL (and return to the analog PLL).
When DWIDTH = 0, termination occurs 8 frames past the fall of the defect detection signal if the defect
detection signal width was less than 12 frames, and 16 frames past the fall of the defect detection signal
if the defect detection signal width was 12 frames or more.
When DWIDTH = 1, termination occurs 4 frames past the fall of the defect detection signal if the defect
detection signal width was less than 12 frames, and 8 frames past the fall of the defect detection signal
if the defect detection signal width was 12 frames or more.
b. Function Selections (Register 9)
BI0 and BI1: These bits select normal play, double-speed play, or quadruple-speed play.
Note: When changing the playback speed, always switch the system to CLV stop mode so that the freerunning frequency is adjusted automatically. The period of setting is 30 msec or more.
WG10TL: This bit selects the width of the frame synchronization signal (SYNC) detection window.
WG10TL = 0: The window width is ±10 T.
WG10TL = 1: The window width is ±19 T.
SYLCK0 and SYLCK1: These bits select whether the sync protection state is maintained for 2, 4, 8, or
12 consecutive frames in which the frame synchronization signal (SYNC) is not detected.
CRCQ: In Q code buffer mode (when the QDSEL signal at pin 65 is low), this bit selects whether or
not to insert the QOK flag into the Q code data.
c. Audio Control (Register A)
The audio control commands concerning the DAS output are all ignored in CD-ROM mode, which is
selected when the ROM microprocessor command bit is set to 1.
MUTEL and MUTER: These command bits mute the left and right channels independently.
Attenuation is carried out in eight steps (7/8, 6/8, 5/8, 4/8, 3/8, 2/8, 1/8, 0) with 136 µs per step (at
standard speed).
Notes: 1. Muting begins as soon as the command is input, without waiting for a zero-crossing point.
2. If the external MUTE signal is high, both channels are muted regardless of these commands.
MONO: This bit selects monaural audio output.
Note: When MONO is set to 1, mean-value interpolation is not performed. The only type of interpolation
performed is to hold the preceding value.
ATT: This bit attenuates the audio output level by –12 dB in six steps (7/8, 6/8, 5/8, 4/8, 3/8, 2/8).
Note: If the external MUTE signal is high, both channels are muted regardless of this command bit.
BLGMAIN and BLGSUB: These bits select whether or not to output bilingual audio on the left and
right channels. This command is ignored if “SWLR” = 1.
SOFTMT: This command bit mutes both the left and right channels simultaneously. Attenuation is
carried out in eight steps with 136 µs per step (at standard speed).
Note: If the external MUTE signal is high, both channels are muted regardless of this command bit.
SWLR: Reverses the left- and right-channel outputs, by reversing DATA from RAM.
Note: Clear this bit to 0 when using DAS subcode output.
Rev.2, Aug. 1995, page 25 of 41
HD49235FS
d. Track Counter Setting (Register B)
An internal counter counts the track-crossing signal input at the CNIN pin. When the count reaches the
value set in register B, the SENS output inverts.
Depending on the order in which registers B and C are set, tracks are counted in complete mode (once
only) or count mode (repeatedly). See the timing diagram in figure 14.
 Complete mode
Step 1: Set desired values in all registers other than registers B and C.
Step 2: Set register C.
Step 3: Set the count value in register B.
Step 4: Monitor the SENS line at the microprocessor.
Microprocessor
command
Step 1
Step 2
Step 3
Step 4
XLT
CNIN
Complete mode
n counts
SENS
n counts
Count mode
n counts
n counts
Figure 14 Track Counting
 Count mode
Step 1: Same as complete mode.
Step 2: Set the count value in register B.
Step 3: Set register C.
Step 4: Monitor the SENS line at the microprocessor.
Notes: 1. Do not use the microprocessor interface while the microprocessor is monitoring the SENS line.
2. If all zeros are written in register B, the count setting is 256.
3. Do not monitor the SENS pin between steps 2 and 3.
Rev.2, Aug. 1995, page 26 of 41
HD49235FS
e. CLV Control (Register C)
AINTV: When a disc is played in CLV mode, the switchover between the starting servo and normal
servo modes is made automatically by testing the number of sync pulses per interval. The AINTV bit
selects the length of the interval.
ATH: When a disc is played in CLV mode, the switchover between the starting servo and normal servo
modes is made automatically by testing the number of sync pulses per interval. The ATH bit selects the
threshold number of pulses. Starting servo mode is used if the number of sync pulses detected in the
interval selected by AINTV is less than the threshold value selected by ATH. Normal servo mode is
used if the number exceeds this threshold. Only sync pulses that are validated by the sync protection
function are counted.
GAIN1 and GAIN0: These command bits select the gain of the output at the PWM pin in normal CLV
servo mode. There are three selections: –6 dB, 0 dB, and +6 dB.
SGAIN1 and SGAIN0: These bits select the PWM gain to be one of three values, –6 dB, 0 dB or 6 dB,
in start mode.
PDGAIN1 and PDGAIN0: These bits select the MSTOP pin output (CLV phase error) gain to be one
of three values, –6 dB, 0 dB or 6 dB.
f. CLV Kick Control (Register D)
KICK7 to KICK1: When kick control is enabled (by microprocessor command register E) in CLV
mode, these bits select the CLV control output pin PWM duty cycle to be one of 128 levels. For
example, to set the duty to be 74/128, set bits D7 to D0 in microprocessor control register D to be
1001010 (base 2).
PWM
*
1
*: D7 × 64 + D6 × 32 + D5 × 16 + D4 × 8 + D3 × 4 + D2 × 2 + D1 × 1
128
128
128
128
128
128
128
Figure 15 CLV Kick Control Output
Rev.2, Aug. 1995, page 27 of 41
HD49235FS
g. CLV Mode (Register E)
This register determines the constant linear velocity control mode. Command data written in bits D7 to
D4 (ED3 to ED0) of register E selects stop, play, rotate, kick, brake, access, start, or normal mode. For
details of these operating modes, see the description of the CLV servo block.
h. ECU Mode (Register F)
The error-correcting capability of the error-correcting unit (ECU) can be selected. Correction when a
track jump occurs can be limited to two symbols at the C1 level and three symbols at the C2 level by
setting bit AS0 to 1, to reduce the likelihood of false corrections.
Sync Protection Block
The pulse width of the EFM signal read from the disc is measured, using the crystal oscillator clock as a
time base. The pulse width value is used to detect the synchronization pattern consisting of the first 24 bits
in each frame, and produce a synchronization pulse named ASYNC.
Due to disc defects and other causes, ASYNC may be detected in an incorrect position, so a divide-by-576
counter* is used to establish a window, and only ASYNC pulses detected within this window are regarded
as valid synchronization pulses (referred to as valid ASYNC pulses). Other synchronization pulses are
disregarded. The width of this window can be set to one of two values by the microprocessor command
WG10TL as follows.
WG10TL = 0: The window width is set to ±10T (±1.7%)
WG10TL = 1: The window width is set to ±19T (±3.1%)
Valid ASYNC pulses occur with correct synchronization timing, but they may sometimes be missing, e.g.
because of rejection of pulses outside the detection window. Where valid ASYNC pulses are missing,
PSYNC pulses are generated by interpolation. Valid ASYNC and PSYNC are the basic constant linear
velocity control signals used in the CLV motor control circuit.
When two consecutive valid ASYNC pulses are detected, the chip assumes that it has acquired
synchronization lock and drives the SLOCK pin high.
If valid ASYNCs are not detected for a consecutive number of times set by the SYLCK0 and SYLCK1
microprocessor command bits, interpolation is stopped and the SLOCK pin is driven low.
When (SYLCK1, SYLCK0) are (0, 0): if ASYNCs are missing for 2 consecutive times interpolation is
stopped and the SLOCK pin goes low.
When (SYLCK1, SYLCK0) are (0, 1): if ASYNCs are missing for 4 consecutive times interpolation is
stopped and the SLOCK pin goes low.
When (SYLCK1, SYLCK0) are (1, 0): if ASYNCs are missing for 8 consecutive times interpolation is
stopped and the SLOCK pin goes low.
When (SYLCK1, SYLCK0) are (1, 1): if ASYNCs are missing for 12 consecutive times interpolation is
stopped and the SLOCK pin goes low.
Figure 17 is a timing diagram for the valid ASYNC and SLOCK relationships for the case where detection
of two consecutive missing valid ASYNCs was specified by microprocessor command.
Note: * 4.2336 MHz/576 = 7.35 kHz (standard speed playback)
Rev.2, Aug. 1995, page 28 of 41
HD49235FS
SLOCK: This output pin indicates whether sync signals were detected correctly during disc playback.
This signal goes high when correct sync signals are detected in two consecutive frames, and goes low
when sync signals are missing consecutively for the number of times specified by the SYLCK0 and
SYLCK1 microprocessor command bits.
PWL
PWH
Sync pattern
Figure 16 Sync Pattern at Start of Frame
Valid ASYNC missing
Valid ASYNC
×
×
×
×
×
Valid ASYNC
SLOCK
Goes high when valid
ASYNC is detected
twice consecutively
Goes low when valid ASYNC is missing
consecutively a number of times
selected by microprocessor command
bits SYLCK0 and SYLCK1*
Note: * This figure is for the case when two consecutive missing ASYNCs is specified.
Figure 17 Valid ASYNC and SLOCK Relationships
Rev.2, Aug. 1995, page 29 of 41
HD49235FS
CLV Servo Control
Compact discs (CDs) are recorded at a constant linear velocity (CLV). This block performs CLV motor
control.
MSTOP: This CLV phase error output pin either is in the high-impedance state, or outputs a constant
low signal, a constant high signal, or a pulse-width modulated waveform with a duty cycle of 0 to
100%, depending on the CLV operating mode.
PWM: This CLV velocity error output pin either is in the high-impedance state, outputs a constant low
signal, outputs a constant high signal, or outputs a pulse-width modulated waveform with a duty cycle
of 0 to 100%, depending on the CLV operating mode.
MON: This output signal indicates when the disc motor is on. When the disc motor is on, this pin is at
the high level, except in stop mode.
PW64: This pin outputs the brake release signal.
ROTD: This pin can be used to monitor the most significant bit of the 7-bit (128-step) output at the
PWM pin.
CLVS: This output pin differentiates between the starting and normal CLV modes. High output
indicates normal mode.
Next the operating modes will be described. Table 2 indicates the CLV control output states in each
mode.
Table 2
CLV Control Output
Outputs Signals
CLV Mode
ED3 to 0
MON
MSTOP (Phase Error)
PWM (Speed Error)
STOP
0000
L
Z
Z
PLAY
0110
H
50% (starting mode)
0 to 100% (normal mode)
0 to 100%
ROT
1000
H
50%
H
KICK
1001
H
50%
Set by microprocessor
BRAKE
1010
H
50%
L
ACS
1100
H
50%
0 to 100%
START
1110
H
50%
0 to 100%
NORM
1111
H
0 to 100%
0 to 100%
1. Stop Mode
This is the state in which the motor is stopped. The free-running frequency of the data strobe VCO is
automatically adjusted in this mode.
Rev.2, Aug. 1995, page 30 of 41
HD49235FS
2. Play Mode
This mode is automatically subdivided into a starting mode (rough servo control) and normal mode
(fine servo control) according to the rate at which sync signals are detected from the disc. The AINTV
and ATH bits in register C (CLV control) select an interval length and threshold value. Starting mode is
used if the number of sync signals in the selected interval is less than the threshold value. Normal mode
is used if the number exceeds the threshold value. Starting and normal modes operate as follows.
Starting Mode: See table 2 for the outputs at the MON and MSTOP pins. The PWM pin outputs a
rectangular wave with a duty cycle corresponding to the arithmetic mean of the pulse width on the 11-T
low side and 11-T high side in the sync signal detected from the disc. See the PWM output duty cycle
characteristic in figure 18.
Center of S-curve of starting servo
Center during play
Gain: +6 dB
100
Gain: 0 dB
92.1
PWM duty cycle (%)
83.5
79.5
74.8
Gain: –6 dB
70.9
66.9
64.6
58.3
54.3
52.0
45.7
41.7
39.4
PWL
PWH
Sync pattern
33.1
29.1
25.2
11T
Slow rotation
Fast rotation
0
–4.6
–2.3 –0.3 0.85 2.3
0
4.6
6.9
9.2
PWL + PWH
2
11T – 1 × 100 [%]
Figure 18 Duty Cycle Characteristic of PWM Output (Speed Error) in CLV Starting Mode
Rev.2, Aug. 1995, page 31 of 41
HD49235FS
Normal Mode: The MON output pin is held high. The PWM pin outputs a rectangular wave with a
duty cycle that depends on the length of four cycles of the sync signal reproduced from the disc (four
frames). See the PWM output duty cycle characteristic in figure 19. The MSTOP pin outputs a phase
error signal obtained by comparing the phase of a signal obtained by prescaling the sync signal by a
factor of four (to give a cycle length of four frames) with the phase of an internal reference signal. See
the MSTOP output duty cycle characteristic in figure 20.
3. Rotate Mode
The MON and PWM outputs are held high. The MSTOP pin outputs a square wave with a 50% duty
cycle. This mode is used to force the disc motor to rotate.
4. Kick Mode
The MON output pin is held high. The MSTOP pin outputs a square wave with a 50% duty cycle. The
PWM pin outputs a rectangular wave with a duty cycle that can be set to any value from 0 to 100% in
128 steps by setting bits KICK7 to KICK1 in microprocessor command register D.
5. Brake Mode
The MON output is held high. The MSTOP pin outputs a square wave with a 50% duty cycle. The
PWM output is held low. This mode is used to force the disc motor to rotate in reverse. In brake mode,
the interval between edges of the EFM signal is measured. If the interval is 32 T or more (T = 1/4.3218
MHz) the SENS output is driven low and the PW64 output is driven low. These outputs can be
monitored to find if braking has been effective.
6. Access (ACS) Mode
Operation is the same as in the starting submode of play mode. This mode is used in track access.
7. Start mode
Operation is the same as in the starting submode of play mode.
8. Normal Mode
Operation is the same as in the normal submode of play mode.
PWM duty cycle
(%)
100
+6 dB
0 dB
7 bit 128 step
75
–6 dB
–64T
–32T
32T
–6 dB
25
0 dB
64T
Center: 588 T (1 frame) × 4 = 2352 T
+6 dB
0
Figure 19 Duty Cycle Characteristic of PWM Output (Speed Error) in CLV Normal Mode
Rev.2, Aug. 1995, page 32 of 41
HD49235FS
100%
– π
0%
0
+ π
Four frames
Figure 20 Duty Cycle Characteristic of MSTOP Output for Constant Linear Velocity Control
Microprocessor
command
Selecting register E
XLT
Interval between EFM edges ≥ 32 T
SENS
Figure 21 SENS Output in Brake Mode
Digital Audio Interface
BIDAT: Digital audio interface output pin. The output can be switched on or off by microprocessor
command DOOFF (in register 8).
Interpolation
A microprocessor command SLTSW (register 8) can select the 48-fs or 64-fs clock. Figures 22 and 23
show the output timing. With the 48-fs clock, a microprocessor command SUBCO (register 8) can select
whether or not to insert subcode data in the DAS output. Figures 24 and 25 show the output timing.
DAS: This pin outputs audio or ROM data. The ROM microprocessor command (in register 8) can select
whether or not to carry out interpolation. Preceding-value and mean-value interpolation are carried out.
With a 48-fs clock, the data is output MSB first and squeezed to the rear. With a 64-fs clock, the data is
output LSB first and squeezed to the rear.
CKX: This pin outputs the data transfer clock.
MPX: This pin outputs a signal that distinguishes between the left and right channels. With a 64-fs clock,
low output indicates the left channel and high output indicates the right channel. With a
48-fs clock, this polarity is reversed.
QMX: This pin outputs a clock signal with four times the frequency of MPX.
DMX: This pin outputs a clock signal with two times the frequency of MPX.
Rev.2, Aug. 1995, page 33 of 41
HD49235FS
C2F: This output pin goes high to flag data errors that could not be corrected by C2 error correction. C2F is
low when there are no such uncorrectable errors. C2F is synchronized to the data output on the DAS line.
When audio is selected by the ROM microprocessor command, this signal is output once for every two
bytes on the left and right channels. When CD-ROM is selected, the signal is output once per byte (every 8
bits).
See figure 26 for the output timing.
MUTE: Selects whether to mute the audio data.
Low: Muting is not performed.
High: Muting is performed.
When MUTE goes high, the address control circuit is initialized so as to maximize the RAM frame jitter
margin at that point. This initialization is performed continuously while MUTE is high. Normal
reproduction resumes when MUTE goes low.
Other Pins
MRST: Master reset. The HD49235FS chip resets when MRST goes low, and operates normally when
MRST is high. This pin has a pull-up resistor, so it can be either left open or connected to VDD.
TEST1 to TEST3: These pins input test control signals. These pins have pull-up resistors, so they can be
either left open or connected to VDD.
VDD: Power supply pin.
VSS: Ground pin.
NC: These pins should be left unconnected. Correct operation is not assured if they are connected.
Rev.2, Aug. 1995, page 34 of 41
HD49235FS
R1-MSB
R1
L2-MSB
MSB
L1
LSB
L1-MSB
MSB
R0
16 bit
MSB
DAS
LSB
8 bit
LSB
MPX
L2
CKX
(2.12 MHz)
Figure 22 Audio/ROM Data Output Sequence (When 48-fs Clock is Selected):
DAS Switched at Fall of CKX
R1
LSB
R1-LSB
MSB
L1
LSB
L1-LSB
MSB
R0
MSB
LSB
DAS
16 bit
LSB
16 bit
MPX
L2-LSB
L2
CKX
(2.82 MHz)
Figure 23 Audio/ROM Data Output Sequence (When 64-fs Clock is Selected):
DAS Switched at Rise of CKX
MPX
F/B
SYNC
MSB
R1
LSB
SUB
CODE
MSB
L1
LSB
R0
MSB
DAS
LSB
8 bit
F/B
SYNC
L2
P CODE
Q CODE
R CODE
S CODE
T CODE
U CODE
V CODE
W CODE
F SYNC
B SYNC
Don't care
Don't care
Don't care
Don't care
Don't care
Don't care
CKX
(2.12 MHz)
Figure 24 Audio/ROM Data Output Sequence with Subcode Data Inserted (When 48-fs
Clock is Selected): DAS Switched at Fall of CKX
1 frame
R5 L0 R0 L1 R1 L2 R2 L3 R3 L4 R4 L5 R5 L0 R0 L1 R1
DAS
FSYNC
In audio mode,
(a) FSYNC Timing
FSYNC goes
low at the timing
1 frame
1 sector
of the L2 data
S96 S97 S0 S1 S2 S3 . . . S96 S97 S0 S1 S2
DAS
FSYNC
BSYNC
(b) F/B SYNC Timing
Figure 25 F/B SYNC Signal Timing Diagram
Rev.2, Aug. 1995, page 35 of 41
HD49235FS
MPX
DMX
QMX
DAS
C2F
"CDROM = 1"
"CDROM = 0"
L0
C2 flag for L0:
upper symbol
C2 flag for L0
R0
C2 flag for R0:
lower symbol
L1
C2 flag for R0:
upper symbol
C2 flag for R0
C2F = "H": error
Figure 26 Error Flag Output (Switchable by Upper/Lower-1st Command in ROM Mode)
Rev.2, Aug. 1995, page 36 of 41
HD49235FS
Absolute Maximum Ratings (Ta = 25°C, VSS = 0 V)
Item
Symbol
Value
Unit
Supply voltage
VDD
–0.3 to +7.0
V
Pin voltage*
VT
–0.3 to VDD + 0.3
V
Allowable power dissipation
Pd
450
mW
Operating temperature
Topr
0 to +75
°C
Storage temperature
Tstg
–55 to +125
°C
Note: * VDD + 0.3 V < 7.0 V
Rev.2, Aug. 1995, page 37 of 41
HD49235FS
Electrical Characteristics
Applicable
Pin(s)
Item
Symbol
Min
Typ
Max
Unit
Test Conditions
Operating
supply voltage
VDD
4.5
5.0
5.5
V
Normal-speed, double52, 63, 73
speed, or quadruple-speed
play
Input voltage
(high)
VIH
0.7 × VDD —
—
V
Input voltage
(low)
VIL
—
—
0.3 × VDD V
Output high
voltage 1
VOH1
VDD–0.5
—
—
V
–IOH = 0.6 mA
Output low
voltage 1
VOL1
—
—
0.4
V
IOL = 0.6 mA
Input leakage
current
IIL
–5
0
5
µA
Three-state
ITOL
leakage current
–5
0
5
µA
Input pin pull-up Rip
resistance
10
20
40
kΩ
Amplifier output VAO
2.4
2.5
2.6
V
VAP input (at AP pin): 2.5 V 60
VCO output
4.2
4.7
5.2
MHz
Normal speed
PLLCK
*1
*2
*1
Three-state output pins in
high-impedance state
3, 17, 74,
75
55, 56, 65,
72
54
Notes: 1. Input pins and I/O pins in input mode (except analog pins): 1, 2, 4, 5, 6, 12, 14, 18, 55, 65, 67,
69, 72.
2. The following output pins, I/O pins in output mode, and three-state output pins: 3, 8 to 11, 13, 15,
16, 17, 19 to 27, 57, 64, 66, 74 to 80
Rev.2, Aug. 1995, page 38 of 41
HD49235FS
Application External
CLV
Servo IC
Microprocessor
CD-G
Digital output
DAC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
XRST
CNIN
SENS
DATA
CLK
XLT
VSS (D)
OVFW
S1
QOK
QDATA
CKEXT
SUBOUT
SUBCK
CFCKP
EMP
BIDAT
MUTE
DAS
CKX
MPX
C2F
QMX
DMX
HD49235FS
PDOUT1
VDD(A)
AMPP
AMPM
AMPO
AC
VSS (A)
PIOUT2
TEST1
MRST
PLLCK
NC
VDD(D)
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
UCK
TC1
MCK
NC
XCO
XCI
VSS(D)
NC
NC
NC
NC
NC
NC
NC
NC
NC
Servo IC
SLOCK
CLVS
ROTD
PW64
MSTOP
MON
PWM
VDD(D)
UCKSL
TEST3
TEST2
DEFCT
EFMI
DSLCI
DSLCO
QDSEL
80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
Rev.2, Aug. 1995, page 39 of 41
HD49235FS
Package Dimensions
Unit: mm
24.8 ± 0.4
20
41
65
40
80
25
0.15
Rev.2, Aug. 1995, page 40 of 41
2.70
0.8
0.17 ± 0.05
0.15 ± 0.04
24
0.15 M
0.20 +0.10
–0.20
1
0.37 ± 0.08
0.35 ± 0.06
3.10 Max
0.8
14
18.8 ± 0.4
64
2.4
1.0
0 – 10˚
1.2 ± 0.2
Hitachi Code
JEDEC Code
EIAJ Code
Weight
FP-80B
—
—
1.7 g
HD49235FS
Disclaimer
1. Hitachi neither warrants nor grants licenses of any rights of Hitachi’s or any third party’s patent,
copyright, trademark, or other intellectual property rights for information contained in this document.
Hitachi bears no responsibility for problems that may arise with third party’s rights, including
intellectual property rights, in connection with use of the information contained in this document.
2. Products and product specifications may be subject to change without notice. Confirm that you have
received the latest product standards or specifications before final design, purchase or use.
3. Hitachi makes every attempt to ensure that its products are of high quality and reliability. However,
contact Hitachi’s sales office before using the product in an application that demands especially high
quality and reliability or where its failure or malfunction may directly threaten human life or cause risk
of bodily injury, such as aerospace, aeronautics, nuclear power, combustion control, transportation,
traffic, safety equipment or medical equipment for life support.
4. Design your application so that the product is used within the ranges guaranteed by Hitachi particularly
for maximum rating, operating supply voltage range, heat radiation characteristics, installation
conditions and other characteristics. Hitachi bears no responsibility for failure or damage when used
beyond the guaranteed ranges. Even within the guaranteed ranges, consider normally foreseeable
failure rates or failure modes in semiconductor devices and employ systemic measures such as failsafes, so that the equipment incorporating Hitachi product does not cause bodily injury, fire or other
consequential damage due to operation of the Hitachi product.
5. This product is not designed to be radiation resistant.
6. No one is permitted to reproduce or duplicate, in any form, the whole or part of this document without
written approval from Hitachi.
7. Contact Hitachi’s sales office for any questions regarding this document or Hitachi semiconductor
products.
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Copyright  Hitachi, Ltd., 2000. All rights reserved. Printed in Japan.
Colophon 2.0
Rev.2, Aug. 1995, page 41 of 41