Philips SAA7327H-M1, SAA7327H-M2A Datasheet

DATA SH EET

Product speciﬁcation File under Integrated Circuits, IC01

1999 Jun 17

INTEGRATED CIRCUITS

SAA7327

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

1999 Jun 17 2

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

CONTENTS

1 FEATURES 2 GENERAL DESCRIPTION 3 ORDERING INFORMATION 4 QUICK REFERENCE DATA 5 BLOCK DIAGRAM 6 PINNING 7 FUNCTIONAL DESCRIPTION

7.1 Decoder part

7.1.1 Principal operational modes of the decoder

7.1.2 Decoding speed and crystal frequency

7.1.3 Lock-to-disc mode

7.1.4 Standby modes

7.2 Crystal oscillator

7.3 Data slicer and clock regenerator

7.4 Demodulator

7.4.1 Frame sync protection

7.4.2 EFM demodulation

7.5 Subcode data processing

7.5.1 Q-channel processing

7.5.2 EIAJ 3 and 4-wire subcode (CD graphics) interfaces

7.5.3 V4 subcode interface

7.6 FIFO and error corrector

7.6.1 Flags output (CFLG)

7.7 Audio functions

7.7.1 De-emphasis and phase linearity

7.7.2 Digital oversampling filter

7.7.3 Concealment

7.7.4 Mute, full-scale, attenuation and fade

7.7.5 Peak detector

7.8 DAC interface

7.8.1 Internal bitstream Digital-to-Analog Converter (DAC)

7.8.2 External DAC interface

7.9 EBU interface

7.9.1 Format

7.10 KILL circuit

7.11 Audio features off

7.12 The VIA interface

7.13 Spindle motor control

7.13.1 Motor output modes

7.13.2 Spindle motor operating modes

7.13.3 Loop characteristics

7.13.4 FIFO overflow

7.14 Servo part

7.14.1 Diode signal processing

7.14.2 Signal conditioning

7.14.3 Focus servo system

7.14.4 Radial servo system

7.14.5 Off-track counting

7.14.6 Defect detection

7.14.7 Off-track detection

7.14.8 High-level features

7.14.9 Driver interface

7.14.10 Laser interface

7.14.11 Radial shock detector

7.15 Microcontroller interface

7.15.1 Microcontroller interface (4-wire bus mode)

7.15.2 Microcontroller interface (I2C-bus mode)

7.15.3 Decoder registers and shadow registers

7.15.4 Summary of functions controlled by decoder registers 0 to F

7.15.5 Summary of functions controlled by shadow registers

7.15.6 Summary of servo commands

7.15.7 Summary of servo command parameters

8 LIMITING VALUES 9 CHARACTERISTICS 10 OPERATING CHARACTERISTICS

(SUBCODE INTERFACE TIMING)

11 OPERATING CHARACTERISTICS (I2S-BUS

TIMING)

12 OPERATING CHARACTERISTICS

(MICROCONTROLLER INTERFACE TIMING)

13 APPLICATION INFORMATION 14 PACKAGE OUTLINE 15 SOLDERING

15.1 Introduction to soldering surface mount packages

15.2 Reflow soldering

15.3 Wave soldering

15.4 Manual soldering

15.5 Suitability of surface mount IC packages for wave and reflow soldering methods

16 DEFINITIONS 17 LIFE SUPPORT APPLICATIONS 18 PURCHASE OF PHILIPS I2C COMPONENTS

1999 Jun 17 3

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

1 FEATURES

• Integrated bitstream DAC with differential outputs, operating at 96fs with 3rd order noise shaper; typical performance of −95 dB signal-to-noise ratio (EIAJ A-weighted)

• Separate serial input and output interfaces allow data ‘loopback’ mode for use of onboard DAC as stand-alone DAC for digital audio signals

• Up to 2 times speed mode

• Lock-to-disc mode

• Full error correction strategy, t = 2 and e = 4

• Full subcode (CD graphics) interface

• All standard decoder functions implemented digitally on

chip

• FIFO overflow concealment for rotational shock resistance

• Digital audio interface (EBU), audio and data

• 2 and 4 times oversampling integrated digital filter,

including fsmode

• Audio data peak level detection

• Kill interface for external DAC deactivation during digital

silence

• All SAA737x (CD7) digital servo and high-level functions

• Low focus noise

• Improved playability performance

• Automatic closed-loop gain control available for focus

and radial loops

• Pulsed sledge support

• Electronic damping of fast radial actuator during long

jump

• Microcontroller loading LOW

• High-level servo control option

• High-level mechanism monitor

• Communication may be via TDA1301/SAA7345

compatible bus or I

C-bus

• On-chip clock multiplier allows the use of 8.4672,

16.9344 or 33.8688 MHz crystals or ceramic resonators.

2 GENERAL DESCRIPTION

The SAA7327 (CD7 II) is a single chip combining the functions of a CD decoder, digital servo and bitstream DAC, especially designed for Video CD applications. The decoder/servo part is based on the SAA737x (CD7) and is software compatible with this design. Extra functions are controlled by use of ‘shadow’ registers (see Section 7.15.3).

Supply of this Compact Disc IC does not convey an implied license under any patent right to use this IC in any Compact Disc application.

3 ORDERING INFORMATION

TYPE

NUMBER

PACKAGE

NAME DESCRIPTION VERSION

SAA7327H QFP64 plastic quad ﬂat package; 64 leads (lead length 1.6 mm);

body 14 × 14 × 2.7 mm

SOT393-1

1999 Jun 17 4

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

4 QUICK REFERENCE DATA

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

supply voltage 3.0 3.3 3.6 V

supply current n = 1 mode − 20 − mA

xtal

crystal frequency 8 8.4672 35 MHz

amb

ambient temperature −10 − +70 °C

stg

storage temperature −55 − +125 °C

S/N

DAC

onboard DAC signal-to-noise ratio

1 kHz; 1fs; EIAJ A-weighted; see Figs 38 and 39

−90 −95 − dB

1999 Jun 17 5

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

5 BLOCK DIAGRAM

Fig.1 Block diagram.

handbook, full pagewidth

DECODER

MICRO-

CONTROLLER

INTERFACE

VERSATILE PINS

INTERFACE

SUBCODE

PROCESSOR

KILL

PEAK

DETECT

SERIAL DATA

INTERFACE

TIMING

TEST

ADC

ref

GENERATOR

FRONT-END

DIGITAL

PLL

MOTOR

CONTROL

AUDIO

PROCESSOR

EBU

INTERFACE

ERROR

CORRECTOR

MICROCONTROLLER

INTERFACE

PRE-

PROCESSING

CONTROL

FUNCTION

CONTROL

PART

EFM

DEMODULATOR

SRAM

RAM

ADDRESSER

OUTPUT STAGES

FLAGS

12 13

40 39 41 42

2 1 3 6

25 31 44

24 16 15 26 49

48 47 46 45

63 34 61 62 32

8 9 10 11 4 14 5 17 33 50 58 52 57

54 55 56

59 60

30 29 28 27

RIN

ref

SCL SDA RAB

SILD

HFIN

HFREF

ISLICE

TEST1 TEST2 TEST3

SELPLL

CRIN

CROUT

CL16

CL11/4

SBSY SFSY

SUB RCK

STATUS

D1 D2 D3 D4

SSA1

DDA2

SSD2

DDD2(C)

SSA2

DDA1

SSD1

SSD3

DDD1(P)

V1 V2/V3 V4 V5 KILL

DATA

WCLK

SCLK

SERIAL DATA

(LOOPBACK)

INTERFACE

37 35 36

SDI

WCLI

SCLI

BITSTREAM

DAC

20 21 18 19

pos

neg

DOBM

MOTO2

MOTO1

LDON

CFLG

RESET

SAA7327

MGS234

1999 Jun 17 6

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

6 PINNING

SYMBOL PIN DESCRIPTION

HFREF 1 comparator common mode input HFIN 2 comparator signal input ISLICE 3 current feedback output from data slicer V

SSA1

(1)

analog ground 1

DDA1

(1)

analog supply voltage 1

ref

6 reference current output

RIN

7 reference voltage for servo ADCs D1 8 unipolar current input 1 (central diode signal input) D2 9 unipolar current input 2 (central diode signal input) D3 10 unipolar current input 3 (central diode signal input) D4 11 unipolar current input 4 (central diode signal input) R1 12 unipolar current input 1 (satellite diode signal input) R2 13 unipolar current input 2 (satellite diode signal input) V

SSA2

(1)

analog ground 2 CROUT 15 crystal/resonator output CRIN 16 crystal/resonator input V

DDA2

(1)

analog supply voltage 2 LN 18 DAC left channel differential negative output LP 19 DAC left channel differential positive output V

neg

20 DAC negative reference input

pos

21 DAC positive reference input RN 22 DAC right channel differential negative output RP 23 DAC right channel differential positive output SELPLL 24 selects whether internal clock multiplier PLL is used TEST1 25 test control input 1 (this pin should be tied LOW) CL16 26 16.9344 MHz system clock output DATA 27 serial d4(1) data output (3-state) WCLK 28 word clock output (3-state) SCLK 29 serial bit clock output (3-state) EF 30 C2 error ﬂag output (3-state) TEST2 31 test control input 2 (this pin should be tied LOW) KILL 32 kill output (programmable; open-drain) V

SSD1

(1)

digital ground 1 V2/V3 34 versatile I/O: versatile input 2 or versatile output 3 (open-drain) WCLI 35 word clock input (for data loopback to DAC) SDI 36 serial data input (for data loopback to DAC) SCLI 37 serial bit clock input (for data loopback to DAC) RESET 38 Power-on reset input (active LOW) SDA 39 microcontroller interface data I/O line (I

C-bus; open-drain output)

SCL 40 microcontroller interface clock line input (I

C-bus)

1999 Jun 17 7

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

Note

1. All supply pins must be connected to the same external power supply voltage.

RAB 41 microcontroller interface R/

W and load control line input (4-wire bus mode)

SILD 42 microcontroller interface

R/W and load control line input (4-wire bus mode) STATUS 43 servo interrupt request line/decoder status register output (open-drain) TEST3 44 test control input 3 (this pin should be tied LOW) RCK 45 subcode clock input SUB 46 P-to-W subcode bits output (3-state) SFSY 47 subcode frame sync output (3-state) SBSY 48 subcode block sync output (3-state) CL11/4 49 11.2896 or 4.2336 MHz (for microcontroller) clock output V

SSD2

(1)

digital ground 2 DOBM 51 bi-phase mark output (externally buffered; 3-state) V

DDD1(P)

(1)

digital supply voltage 1 for periphery CFLG 53 correction ﬂag output (open-drain) RA 54 radial actuator output FO 55 focus actuator output SL 56 sledge control output V

DDD2(C)

(1)

digital supply voltage 2 for core V

SSD3

(1)

digital ground 3 MOTO1 59 motor output 1; versatile (3-state) MOTO2 60 motor output 2; versatile (3-state) V4 61 versatile output 4 V5 62 versatile output 5 V1 63 versatile input 1 LDON 64 laser drive on output (open-drain)

SYMBOL PIN DESCRIPTION

1999 Jun 17 8

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

Fig.2 Pin configuration.

handbook, full pagewidth

SAA7327H

MGS249

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

48 47 46 45 44 43 42 41 40 39 38 37 36 35 34

SBSY SFSY SUB RCK TEST3 STATUS SILD RAB SCL SDA

SCLI SDI WCLI V2/V3 V

SSD1

HFREF

HFIN ISLICE V

SSA1

DDA1

ref

RIN

D1 D2 D3 D4 R1 R2

SSA2

CROUT

CRIN 33

LDONV1V5

MOTO2

MOTO1

SSD3VDDD2(C)

CFLG

DDD1(P)

DOBM

SSD2

CL11/4

DDA2

neg

pos

SELPLL

TEST1

CL16

DATA

WCLK

SCLK

TEST2

KILL 49

RESET

7 FUNCTIONAL DESCRIPTION

7.1 Decoder part

7.1.1 P

RINCIPAL OPERATIONAL MODES OF THE DECODER

The decoding part supports a full audio specification and can operate at two different disc speeds, from single-speed (n = 1) to 2 times speed (n = 2). The factor ‘n’ is called the overspeed factor. A simplified data flow through the decoder part is illustrated in Fig.7.

7.1.2 DECODING SPEED AND CRYSTAL FREQUENCY The SAA7327 is a two speed decoding device, with an

internal Phase-Locked Loop (PLL) clock multiplier. Depending on the crystal frequency used and the internal clock settings (selectable via decoder register B), the playback speeds shown in Table 1 are possible, where ‘n’ is the overspeed factor (1 or 2).

An internal clock multiplier is present, controlled by SELPLL, and should only be used if a 8.4672 or

16.9344 MHz crystal, ceramic resonator or external clock is present.

1999 Jun 17 9

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.1.3 LOCK-TO-DISC MODE For Electronic Shock Absorption (ESA) applications, the

SAA7327 can be put into lock-to-disc mode. This allows Constant Angular Velocity (CAV) disc playback with varying input data rates from the inside-to-outside of the disc.

In the lock-to-disc mode, the FIFO is blocked and the decoder will adjust its output data rate to the disc speed. Hence, the frequency of the I2S-bus (WCLK and SCLK) clocks are dependent on the disc speed. In the lock-to-disc mode there is a limit on the maximum variation in disc speed that the SAA7327 will follow. Disc speeds must always be within 25% to 100% range of their nominal value. The lock-to-disc mode is enabled/disabled by decoder register E.

7.1.4 S

TANDBY MODES

The SAA7327 may be placed in two standby modes selected by decoder register B (it should be noted that the device core is still active):

• Standby 1: ‘CD-STOP’ mode; most I/O functions are switched off

• Standby 2: ‘CD-PAUSE’ mode; audio output features are switched off, but the motor loop, the motor output and the subcode interfaces remain active; this is also called a ‘Hot Pause’.

In the standby modes the various pins will have the following values:

• MOTO1 and MOTO2: put in high-impedance, PWM mode (standby 1 and reset: operating in standby 2); put in high-impedance, PDM mode (standby 1 and reset: operating in standby 2)

• SCL and SDA: no interaction; normal operation continues

• SCLK, WCLK, DATA, EF and DOBM: 3-state in both standby modes; normal operation continues after reset

• CRIN, CROUT, CL16 and CL11/4: no interaction; normal operation continues

• V1, V2/V3, V4, V5 and CFLG: no interaction; normal operation continues.

Table 1 Playback speeds

Notes

1. The CL11 output is always a 5.6448 MHz clock if a 16.9344 MHz external clock is used and SELPLL = 0. CL11 is available on the CL11/4 output, enabled by programming shadow register 3 (see Section 7.15.3).

2. Data capture performance is not optimized for this option.

CRYSTAL FREQUENCY (MHz) CL11

FREQUENCY

(MHz)

(1)33.8688 16.9344 8.4672

00XX 0 n = 1 −−11.2896 00XX 1 −−n = 1 11.2896 01XX 0 − n=1 − 5.6448 01XX 1 − n=1 − 11.2896 10XX 0 n = 2 −−11.2896 10XX 1 −−n = 2 11.2896 11XX 0 − n=2

(2)

− 5.6448

11XX 1 − n=2 − 11.2896

1999 Jun 17 10

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.2 Crystal oscillator

The crystal oscillator is a conventional 2-pin design operating between 8 and 35 MHz. This oscillator is capable of operating with ceramic resonators and with both fundamental and third overtone crystals. External components should be used to suppress the fundamental output of the third overtone crystals as shown in Figs 3 and 4. Typical oscillation frequencies required are

8.4672, 16.9344 or 33.8688 MHz depending on the

internal clock settings used and whether or not the clock multiplier is enabled.

Fig.3 8.4672 MHz fundamental configuration.

handbook, halfpage

OSCILLATOR

8.4672 MHz

CRIN

CROUT

SAA7327

33 pF33 pF

MGS246

Fig.4 33.8688 MHz overtone configuration.

handbook, halfpage

OSCILLATOR

33.8688 MHz

CRIN

CROUT

SAA7327

3.3 µH

1 nF10 pF10 pF

MGS247

7.3 Data slicer and clock regenerator

The SAA7327 has an integrated slice level comparator which can be clocked by the crystal frequency clock, or 4 times the crystal frequency clock (if SELPLL is set HIGH while using a 16.9344 MHz crystal and register 4 is set to 0XXX), or 8 times the crystal frequency clock (if SELPLL is set HIGH while using an 8.4672 MHz crystal, and register 4 is set to 0XXX). The slice level is controlled by an internal current source applied to an external capacitor under the control of the Digital Phase-Locked Loop (DPLL).

Regeneration of the bit clock is achieved with an internal fully digital PLL. No external components are required and the bit clock is not output. The PLL has two registers (8 and 9) for selecting bandwidth and equalization. The PLL response is shown in Fig.5.

For certain applications an off-track input is necessary. This is internally connected from the servo part (its polarity can be changed by the foc_parm1 parameter), but may be input via the V1 pin if selected by register C. If this flag is HIGH, the SAA7327 will assume that its servo part is following on the wrong track, and will flag all incoming HF data as incorrect.

Fig.5 Digital PLL loop response.

MGS178

handbook, halfpage

3. PLL, LPF

2. PLL bandwidth

1. PLL integrator

PLL loop

response

1, 2and 3 are programmable via decoder register 8.

1999 Jun 17 11

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

Fig.6 Data slicer showing typical application components (for n = 1).

47 pF

HFREF

HFIN

ISLICE

22 kΩ

2.2 kΩ

100 nF

1 nF

HF input

crystal

clock

DPLL

SSA

MGS179

100 µA

7.4 Demodulator

7.4.1 F

RAME SYNC PROTECTION

A double timing system is used to protect the demodulator from erroneous sync patterns in the serial data. The master counter is only reset if:

• A sync coincidence is detected; sync pattern occurs

588 ±1 EFM clocks after the previous sync pattern

• A new sync pattern is detected within ±6 EFM clocks of

its expected position.

The sync coincidence signal is also used to generate the PLL lock signal, which is active HIGH after 1 sync coincidence found, and reset LOW if during 61 consecutive frames no sync coincidence is found. The PLL lock signal can be accessed via the SDA or STATUS pins selected by decoder registers 2 and 7.

Also incorporated in the demodulator is a Run Length 2 (RL2) correction circuit. Every symbol detected as RL2 will be pushed back to RL3. To do this, the phase error of both edges of the RL2 symbol are compared and the correction is executed at the side with the highest error probability.

7.4.2 EFM

DEMODULATION

The 14-bit EFM data and subcode words are decoded into 8-bit symbols.

1999 Jun 17 12

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder

with integrated DAC for video CD (CD7 II)

SAA7327

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Fig.7 Simplified data flow of decoder functions.

k, full pagewidth

SUBCODE

PROCESSOR

DIGITAL PLL

AND

DEMODULATOR

FIFO

ERROR

CORRECTOR

FADE/MUTE/

INTERPOLATE

DIGITAL

FILTER

PHASE

COMPENSATION

DE-EMPHASIS

FILTER

KILL

1 0

I2S/EIAJ BUS

INTERFACE

I2S/EIAJ LOOPBACK INTERFACE

WCLI SCLI SDI

LN LP RN RP

SCLK WCLK DATA EF

decoder

reg 3

neg

decoder reg C

decoder reg 3

reg F

decoder reg A

1 0

1: decoder reg 3 ≠ 101X 0: decoder reg 3 = 101X (CD-ROM modes)

1: shadow reg 7 = XX1X 0: shadow reg 7 = XX0X

0: reg D = XX01

1: decoder reg A = XX0X 0: decoder reg A ≠ XX1X

V4 SUBCODE

INTERFACE

MICROCONTROLLER

INTERFACE

CD GRAPHICS

INTERFACE

EBU

INTERFACE

SBSY SFSY SUB

RCK

DOBM

SDA

output from

data slicer

1: decoder reg 3 = XX10 (1fs mode) 0: decoder reg 3 ≠ XX10

1: no pre-emphasis detected OR reg D = 01XX (de-emphasis signal at V5) 0: pre-emphasis detected AND reg D ≠ 01XX

KILL V3

MGS180

1 0

ONBOARD

DAC

1: shadow reg 7 = XXX1 0: shadow reg 7 = XXX0

1 0

1999 Jun 17 13

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.5 Subcode data processing

7.5.1 Q-

CHANNEL PROCESSING

The 96-bit Q-channel word is accumulated in an internal buffer. The last 16 bits are used internally to perform a Cyclic Redundancy Check (CRC). If the data is good, the SUBQREADY-I signal will go LOW. SUBQREADY-I can be read via the SDA or STATUS pins, selected via decoder register 2. Good Q-channel data may be read from SDA.

7.5.2 EIAJ 3

AND 4-WIRE SUBCODE (CD GRAPHICS)

INTERFACES

Data from all the subcode channels (P-to-W) may be read via the subcode interface, which conforms to EIAJ CP-2401. The interface is enabled and configured as either a 3 or 4-wire interface via decoder register F. The subcode interface output formats are illustrated in Fig.8, where the RCK signal is supplied by another device such as a CD graphics decoder.

7.5.3 V4

SUBCODE INTERFACE

Data of subcode channels, Q-to-W, may be read via pin V4 if selected via decoder register D. The format is similar to RS232 and is illustrated in Fig.9. The subcode sync word is formed by a pause of (200/n) µs minimum. Each subcode byte starts with a logic 1 followed by 7 bits (Q-to-W). The gap between bytes is variable between (11.3/n) µs and (90/n) µs.

The subcode data is also available in the EBU output (DOBM) in a similar format.

Fig.8 EIAJ subcode (CD graphics) interface format.

handbook, full pagewidth

SBSY

SFSY

RCK

SUB

SFSY

RCK

SUB

SFSY

RCK

SUB

EIAJ 4-wire subcode interface

EIAJ 3-wire subcode interface

SF0 SF1

SF2 SF3 SF97 SF0 SF1

P-W P-W P-W

PQRSTUVW

MBG410

SF0 SF1 SF2 SF3 SF97 SF0 SF1

1999 Jun 17 14

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

Fig.9 Subcode format and timing on pin V4.

n = disc speed.

W96 1QRSTUVW 1Q

200/n µs

min

11.3/n µs

11.3/n µs min 90/n µs max

MBG401

7.6 FIFO and error corrector

The SAA7327 has a ±8 frame FIFO. The error corrector is a t = 2, e = 4 type, with error corrections on both C1 (32 symbol) and C2 (28 symbol) frames. Four symbols are used from each frame as parity symbols. This error corrector can correct up to two errors on the C1 level and up to four errors on the C2 level.

The error corrector also contains a flag processor. Flags are assigned to symbols when the error corrector cannot ascertain if the symbols are definitely good. C1 generates output flags which are read after (de-interleaving) by C2, to help in the generation of C2 output flags.

The C2 output flags are used by the interpolator for concealment of uncorrectable errors. They are also output via the EBU signal (DOBM). The EF output will flag bytes in error in both audio and CD-ROM modes.

7.6.1 FLAGS OUTPUT (CFLG) The flags output pin CFLG shows the status of the error

corrector and interpolator and is updated every frame (7.35 × n kHz). In the SAA7327 chip a 1-bit flag is present on the CFLG pin as illustrated in Fig.10. This signal shows the status of the error corrector and interpolator.

The first flag bit, F1, is the absolute time sync signal, the FIFO-passed subcode sync and relates the position of the subcode sync to the audio data (DAC output). This flag may also be used in a super FIFO or in the synchronization of different players. The output flags can be made available at bit 4 of the EBU data format (LSB of the 24-bit data word), if selected by decoder register A.

Fig.10 Flag output timing diagram.

n = disc speed.

handbook, full pagewidth

F1 F2 F3 F4 F5 F6 F7 F8 F1F8

11.3/n µs

33.9/n µs

MBG425

1999 Jun 17 15

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

Table 2 Output flags

F1 F2 F3 F4 F5 F6 F7 F8 DESCRIPTION

0XXXXXXXno absolute time sync

1XXXXXXXabsolute time sync X 0 0 X X X X X C1 frame contained no errors X 0 1 X X X X X C1 frame contained 1error X 1 0 X X X X X C1 frame contained 2errors X 1 1 X X X X X C1 frame uncorrectable X X X 0 0 X X 0 C2 frame contained no errors X X X 0 0 X X 1 C2 frame contained 1 error X X X 0 1 X X 0 C2 frame contained 2 errors X X X 0 1 X X 1 C2 frame contained 3 errors X X X 1 0 X X 0 C2 frame contained 4 errors X X X 1 1 X X 1 C2 frame uncorrectable X X X X X 0 0 X no interpolations X X X X X 0 1 X at least one 1-sample interpolation X X X X X 1 0 X at least one hold and no interpolations X X X X X 1 1 X at least one hold and one 1-sample interpolation

7.7 Audio functions

7.7.1 D

E-EMPHASIS AND PHASE LINEARITY

When pre-emphasis is detected in the Q-channel subcode, the digital filter automatically includes a de-emphasis filter section. When de-emphasis is not required, a phase compensation filter section controls the phase of the digital oversampling filter to ≤±1° within the band 0 to 16 kHz. With de-emphasis the filter is not phase linear.

If the de-emphasis signal is set to be available at V5, selected via decoder register D, then the de-emphasis filter is bypassed.

7.7.2 D

IGITAL OVERSAMPLING FILTER

For optimizing performance with an external DAC, the SAA7327 contains a 2 to 4 times oversampling IIR filter. The filter specification of the 4 times oversampling filter is given in Table 3.

These attenuations do not include the sample-and-hold at the external DAC output or the DAC post filter. When using the oversampling filter, the output level is scaled −0.5 dB down, to avoid overflow on full-scale sine wave inputs (0 to 20 kHz).

Table 3 Filter specification

7.7.3 CONCEALMENT A 1-sample linear interpolator becomes active if a single

sample is flagged as erroneous but cannot be corrected. The erroneous sample is replaced by a level midway between the preceding and following samples. Left and right channels have independent interpolators. If more than one consecutive non-correctable sample is found, the last good sample is held. A 1-sample linear interpolation is then performed before the next good sample (see Fig.11).

In CD-ROM modes (i.e. the external DAC interface is selected to be in a CD-ROM format) concealment is not executed.

PASS BAND STOP BAND ATTENUATION

0 to 9 kHz −≤0.001 dB

19 to 20 kHz −≤0.03 dB

− 24 kHz ≥25 dB

− 24 to 27 kHz ≥38 dB

− 27 to 35 kHz ≥40 dB

− 35 to 64 kHz ≥50 dB

− 64 to 68 kHz ≥31 dB

− 68 kHz ≥35 dB

− 69 to 88 kHz ≥40 dB

1999 Jun 17 16

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.7.4 MUTE, FULL-SCALE, ATTENUATION AND FADE A digital level controller is present on the SAA7327 which

performs the functions of soft mute, full-scale, attenuation and fade; these are selected via decoder register 0:

• Mute: signal reduced to 0 in a maximum of 128 steps; (3/n) ms

• Attenuate: signal scaled by −12 dB

• Full-scale: ramp signal back to 0 dB level; from mute

takes (3/n) ms

• Fade: activates a 128 stage counter which allows the signal to be scaled up/down by 0.07 dB steps

– 128 = full-scale – 120 = −0.5 dB (i.e. full-scale if oversampling filter

used) –32=−12 dB – 0 = mute.

7.7.5 PEAK DETECTOR The peak detector measures the highest audio level

(absolute value) on positive peaks for left and right channels. The 8 most significant bits are output in the Q-channel data in place of the CRC bits. Bits 81 to 88 contain the left peak value (bit 88 = MSB) and bits 89 to 96 contain the right peak value (bit 96 = MSB). The values are reset after reading Q-channel data via SDA.

Fig.11 Concealment mechanism.

Interpolation Hold Interpolation

MGA372

OK Error OK Error Error Error OK OK

1999 Jun 17 17

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.8 DAC interface

7.8.1 I

NTERNAL BITSTREAM DIGITAL-TO-ANALOG CONVERTER (DAC)

The onboard bitstream DAC operates at a clock frequency of 96fs and is designed for operation with an audio input at 1fs. Optimum performance is dependent on the application circuit used and careful consideration should be given to the recommended application circuits shown in Figs 38 and 39. The onboard DAC is controlled from shadow register 7 (see Section 7.15.3 for definition of shadow registers). This shadow register controls routing of data into the onboard DAC and also controls the DAC output pins, which can be held at zero when the onboard DAC is not required; see Table 4.

Table 4 Shadow register

Audio data from the decoder part of SAA7327 can be routed as described in the following two subsections.

SHADEN

SHADOW

ADDRESS

1 0111 (7H) control of

onboard DAC

XXX0 hold onboard DAC outputs at

zero

reset

XXX1 enable onboard DAC outputs − XX0X use external DAC or route audio

data into onboard DAC (loopback mode)

reset

XX1X route audio data into onboard

DAC (non-loopback mode)

−

7.8.1.1 Use onboard DAC

In this mode, shadow register 7 should be set to XX11. This routes audio data from the decoder section of CD7 II into the onboard DAC and enables the DAC output pins (LN, LP, RN and RP). It should be noted that the DAC interface format (set by decoder register 3) must be set to 16-bit 1fsmode, either I2S-bus or EIAJ format, for optimum DAC performance to be achieved. CD-ROM mode can also be used if interpolation is not required.

When using this mode, the serial data output pins for interfacing with an external DAC or VCD decoder (SCLK, WCLK, DATA and EF) are set to high-impedance.

7.8.1.2 Loopback external data into onboard DAC

The onboard DAC can also be set to accept digital audio inputs from an external source, e.g. audio from a VCD decoder IC. This is known as loopback mode and is enabled by setting shadow register 7 to XX01. This enables the serial data output pins SCLK, WCLK, DATA and EF so that data can be routed to the external VCD decoder (or external DAC).

The digital audio data output from the VCD decoder can then also be input to the onboard DAC on the SAA7327 by utilising the serial data input interface (SCLI, SDI and WCLI).

In this mode, a wide range of data formats to the external VCD IC can be programmed as shown in Table 4. However, the serial inputs on the SAA7327 will always expect the input digital audio data from the VCD IC to be 16-bit 1fs and the same data format, either I2S-bus or EIAJ, as the serial output format (set by decoder register 3). In fact, the onboard DAC will also accept 18-bit I2S-bus data; in this case the 16 MSBs only will be read and the 2 LSBs discarded.

1999 Jun 17 18

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.8.2 EXTERNAL DAC INTERFACE Audio data from the CD10 decoder can be sent direct to an

external DAC, identical to the SAA737x series. This is similar to the ‘loopback’ mode, but in this case the internal DAC outputs can be held at zero i.e. shadow register 7 is set to XX00. The SAA7327 is compatible with a wide range of external DACs. Eleven formats are supported and are given in Table 4. Figures 12 and 13 show the Philips I2S-bus and the EIAJ data formats respectively. When the decoder is operated in lock-to-disc mode, the SCLK frequency is dependent on the disc speed factor ‘d’.

All formats are MSB first and f

is (44.1 × n) kHz. The polarity of the WCLK and the data can be inverted; selectable by decoder register 7. It should be noted that EF is only a defined output in CD-ROM and 1fsmodes.

When using an external DAC (or when using the onboard DAC in non-loopback mode), the serial data inputs to the onboard DAC (SCLI, SDI and WCLI) should be left unconnected.

Table 5 DAC interface formats

Note

1. In this mode the first 16 bits contain data, but if any of the fade, attenuate or de-emphasis filter functions are activated then the first 18 bits contain data.

SAMPLE

FREQUENCY

NUMBER OF

BITS

SCLK (MHz) FORMAT INTERPOLATION

1010 f

16 2.1168 × n CD-ROM (I2S-bus) no

1011 f

16 2.1168 × n CD-ROM (EIAJ) no

1110 f

16/18

(1)

2.1168 × n Philips I2S-bus 16/18 bits

(1)

yes

0010 f

16 2.1168 × n EIAJ 16 bits yes

0110 f

18 2.1168 × n EIAJ 18 bits yes

0000 4f

16 8.4672 × n EIAJ 16 bits yes

0100 4f

18 8.4672 × n EIAJ 18 bits yes

1100 4f

18 8.4672 × n Philips I2S-bus 18 bits yes

0011 2f

16 4.2336 × n EIAJ 16 bits yes

0111 2f

18 4.2336 × n EIAJ 18 bits yes

1111 2f

18 4.2336 × n Philips I2S-bus 18 bits yes

1999 Jun 17 19

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder

with integrated DAC for video CD (CD7 II)

SAA7327

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LEFT CHANNEL DATA (WCLK NORMAL POLARITY)

SCLK

15 14

15 1410DATA

WCLK

LSB error flag MSB error flag LSB error flag MSB error flag

EF (CD-ROM AND Ifs MODES ONLY)

MBG424

Fig.12 Philips I2S-bus data format (16-bit word length shown).

SCLK

170DATA

WCLK

LEFT CHANNEL DATA

MSB error flag LSB error flag MSB error flag

MBG423

EF (CD-ROM AND Ifs MODES ONLY)

Fig.13 EIAJ data format (18-bit word length shown).

1999 Jun 17 20

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.9 EBU interface

The bi-phase mark digital output signal at pin DOBM is in accordance with the format defined by the IEC958 specification. Three different modes can be selected via decoder register A:

• DOBM pin held LOW

• Data taken before concealment, mute and fade (must

always be used for CD-ROM modes)

• Data taken after concealment, mute and fade.

7.9.1 FORMAT The digital audio output consists of 32-bit words

(‘subframes’) transmitted in bi-phase mark code (two transitions for a logic 1 and one transition for a logic 0). Words are transmitted in blocks of 384. The formats are given in Table 6.

Table 6 Format

Table 7 Description of Table 6

Table 8 Bit assignment

FUNCTION BITS DESCRIPTION

Sync 0 to 3 − Auxiliary 4 to 7 not used; normally zero Error ﬂags 4 CFLG error and interpolation ﬂags when selected by register A Audio sample 8 to 27 ﬁrst 4 bits not used (always zero) twos complement LSB = bit 12, MSB = bit 27 Validity ﬂag 28 valid = logic 0 User data 29 used for subcode data (Q-to-W) Channel status 30 control bits and category code Parity bit 31 even parity for bits 4 to 30

FUNCTION DESCRIPTION

Sync The sync word is formed by violation of the bi-phase rule and therefore does not contain any data.

Its length is equivalent to 4 data bits. The 3 different sync patterns indicate the following situations: sync B: start of a block (384 words), word contains left sample; sync M: word contains left sample

(no block start) and sync W: word contains right sample. Audio sample Left and right samples are transmitted alternately. Validity ﬂag Audio samples are ﬂagged (bit 28 = 1) if an error has been detected but was uncorrectable. This

ﬂag remains the same even if data is taken after concealment. User data Subcode bits Q-to-W from the subcode section are transmitted via the user data bit. This data is

asynchronous with the block rate. Channel status The channel status bit is the same for left and right words. Therefore a block of 384 words contains

192 channel status bits. The category code is always CD. The bit assignment is given in Table 8.

FUNCTION BITS DESCRIPTION

Control 0 to 3 copy of CRC checked Q-channel control bits 0 to 3; bit 2 is logic 1 when

copy permitted; bit 3 is logic 1 when recording has pre-emphasis Reserved mode 4 to 7 always zero Category code 8 to 15 CD: bit 8 = logic 1, all other bits = logic 0 Clock accuracy 28 to 29 set by register A; 10 = level I; 00 = level II; 01 = level III Remaining 6 to 27 and 30 to 191 always zero

1999 Jun 17 21

Philips Semiconductors Product speciﬁcation

Digital servo processor and Compact Disc decoder with integrated DAC for video CD (CD7 II)

SAA7327

7.10 KILL circuit

The KILL circuit detects digital silence by testing for an all-zero or all-ones data word in the left or right channel prior to the digital filter. The output is switched active LOW when silence has been detected for at least 270 ms, or if mute is active, or in CD-ROM modes. Two modes are available which can be selected by decoder register C:

• Pin KILL: KILL active LOW indicates silence detected on both left and right channels

• Pin KILL: KILL active LOW indicates silence detected on left channel. V3 active LOW indicates silence detected on right channel.

It should be noted that when mute is active or in CD-ROM modes the output(s) are switched LOW.

7.11 Audio features off

The audio features can be turned off (selected by decoder register E) which affects the following functions:

• Digital filter, fade, peak detector, KILL circuit (but outputs KILL, V3 still active) are disabled

• V5 (if selected to be the de-emphasis flag output) and the EBU outputs become undefined.

It should be noted that the EBU output should be set LOW prior to switching the audio features off and after switching audio features back on a full-scale command should be given.

7.12 The VIA interface

The SAA73727 has four pins that can be reconfigured for different applications. One of these pins, V2/V3, can be programmed as an input (V2) or as an output (V3). Control of the V2/V3 pin is via shadow register 3; see Table 9:

Selection of the V2/V3 pin does not affect the function programmed by decoder register C i.e. the V2/V3 pin can be changed from V2 to V3 function either before or after setting the desired function via decoder register 1100. Selection of, for instance, a V3 function while the V2/V3 pin is set to V2 will not affect the V2 functionality.

The functions of these versatile pins is identical to the SAA737x series. The functions of these versatile pins is programmed by decoder registers C and D, as shown in Table 10.

Table 9 V2/V3 conﬁguration

Table 10 Pin applications

SHADEN ADDRESS REGISTER DATA FUNCTION RESET

1 0011 (3H) control of

V2/V3 pin

0XXX V2/V3 pin conﬁgured as V2 input reset 1XXX V2/V3 pin conﬁgured as V3 output (open-drain) −

PIN NAME

NUMBER

TYPE

DATA

FUNCTION

V1 63 input 1100 XXX1 external off-track signal input

− XXX0 internal off-track signal used input may be read via decoder status bit; selected via register 2

V2 36 input −−input may be read via decoder status bit;

selected via register 2

V3 36 output 1100 XX0X KILL output for right channel

− X01X output = 0

− X11X output = 1

V4 61 output 1101 0000 4-line motor drive (using V4 and V5)

− XX01 Q-to-W subcode output

− XX10 output = 0

− XX11 output = 1

V5 62 output 1101 01XX de-emphasis output (active HIGH)

− 10XX output = 0

− 11XX output = 1

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