Philips SAA7380GP Datasheet

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DATA SH EET

SAA7380

Error correction and host interface IC for CD-ROM (ELM)

Preliminary speciﬁcation File under Integrated Circuits, IC01

1996 Apr 25

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

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

7.1 CD-DSP interface and data input

7.2 Error correction and EDC check

7.3 Host interface

7.4 Subcode channel Q-to-W buffering

7.5 External buffer memory

7.6 Sub-CPU registers

7.7 Register Descriptions

7.8 Sub-CPU interface

7.9 Host registers .10 CD-DSP Timings

8 LIMITING VALUES 9 THERMAL CHARACTERISTICS 10 CHARACTERISTICS 11 TIMING CHARACTERISTICS

11.1 Q-to-W subcode interface timing

11.2 External memory SRAM timing

11.3 External memory DRAM timing

11.4 Sub-CPU interface timing

11.5 ATAPI host interface timing

11.6 SANYO compatibility mode host interface timing

11.7 Oak compatibility mode host interface timing

11.8 Crystal oscillator

12 PACKAGE OUTLINE 13 SOLDERING 14 DEFINITIONS 15 LIFE SUPPORT APPLICATIONS

SAA7380

1996 Apr 25 2

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

1 FEATURES

• CD-ROM (Mode 1) and CD-I (Mode 2 - Form 1 and

Form 2) formats supported

• Real-time error detection and correction in hardware

• Suitable for 6 × speed, n = 6

• Maximum host transfer burst rate of 11.1 Mbyte/s

• Corrects two errors per symbol with erasure correction

• 36 kbit of on-chip error correction buffer RAM

• 12-byte command FIFO and 12-byte status FIFO

• Compatible with the Advanced Technology Attachment

(ATA) register set and the Advanced Technology Attachment Program Interface (ATAPI) command set

• Operates with popular memories. (up to 128 kbyte

SRAM; 1 to 16 Mbit DRAM, different speed grades, nibble or byte wide)

• Interface to Integrated Drive Electronics (IDE) bus

without external bus drivers

• Q-to-W subcode buffering, de-interleaving and

correction are supported

• Device can operate with audio RAMs. A RAM test allows

bad segments to be identified.

SAA7380

2 GENERAL DESCRIPTION

The SAA7380 decoder is a block decoder buffer manager for high-speed CD-ROM applications that integrates real-time error correction and detection and host interface data transfer functions into a single chip.

The SAA7380 has an on-chip 36-kbit memory. This memory is used as a buffer memory for error and erasure corrections. The chip also has a buffer memory interface thus enabling the connection of SRAM up to 128 kbytes, or DRAM up to 16 Mbits. The on-chip memory is sufficient to buffer 1 sector of data. The external memory can buffer many more, depending on memory size.

The error corrector of the SAA7380 can perform 2-pass error correction in real-time. Buffer memory for this correction is integrated on-chip.

The SAA7380 has an host interface that is compatible with the SANYO LC89510 or OAK OTI-012 and also compatible with the ATA/IDE/ATAPI hard disc interface bus. (All ATAPI registers are present in hardware).

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 QUICK REFERENCE DATA

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

V V I

DDD

clk

T T

DDD1 DDD2

amb stg

digital supply voltage 1 3.0 3.3 3.6 V digital supply voltage 2 4.5 5 5.5 V supply current − 60 − mA clock frequency 15.2 33.8688 35 MHz operating ambient temperature 0 − +70 °C storage temperature −55 − +125 °C

4 ORDERING INFORMATION

PACKAGE

TYPE NUMBER

NAME DESCRIPTION VERSION

SAA7380GP QFP80 plastic quad ﬂat package; 80 leads; lead length 1.95 mm;

SOT318-2

body 14 × 20 × 2.8 mm

1996 Apr 25 3

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

5 BLOCK DIAGRAM

handbook, full pagewidth

DDD1

SDA

SCL

INT

RESET

SYN

DMACK

DA1

DA2/EJECT

CS2/SELRQ

IOCS16

1, 14, 24,

41, 59, 68

36 37 38 39 40

45 70 71 72 73

DGND

CONTROLLER

MICRO-

INTERFACE

DDD2

RCK

SFSY

50, 74 28

HOST INTERFACE

BCKWSDATA

SUB

29 30 31 33 34 35 23 25

DECODER

SERIAL

INTERFACE

ERROR

CORRECTOR

SRAM

CACHE

C2PO TEST1

TEST2

TEST

SAA7380

MEMORY

MANAGER

OSCILLATOR

SAA7380

75-80

2-10

12 11 13

15-22

27 26

RA0 to RA5

RA6 to RA14

RA16/CAS RA15/RAS RWE

RD0 to RD7

CRIN CROUT

42 43 44 69 46 47 48 49

CS1/HEN

HRD

HWR DA0/CMD

IORDY/WAIT/HFBLB

DMARQ/DTEN

SCRST/STEN

IRQ/EOP/HFBC

Fig.1 Block diagram.

1996 Apr 25 4

51-58 60-67

MGE190

HD0 to HD7 HD8 to HD15

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for

SAA7380

CD-ROM (ELM)

6 PINNING

SYMBOL PIN I/O DESCRIPTION

DGND1 1 − digital ground 1 RA6 2 O buffer RAM address bus output line 6 RA7 3 O buffer RAM address bus output line 7 RA8 4 O buffer RAM address bus output line 8 RA9 5 O buffer RAM address bus output line 9 RA10 6 O buffer RAM address bus output line 10 RA11 7 O buffer RAM address bus output line 11 (SRAM) only RA12 8 O buffer RAM address bus output line 12 (SRAM) only RA13 9 O buffer RAM address bus output line 13 (SRAM) only RA14 10 O buffer RAM address bus output line 14 (SRAM) only RA15/RAS 11 O buffer RAM address bus output line 15 (SRAM) or RAS (DRAM) RA16/CAS 12 O buffer RAM address bus output line 16 (SRAM) or CAS (DRAM) RWE 13 O buffer RAM write enable output DGND2 14 − digital ground 2 RD0 15 I/O buffer RAM data bus bidirectional line 0 RD1 16 I/O buffer RAM data bus bidirectional line 1 RD2 17 I/O buffer RAM data bus bidirectional line 2 RD3 18 I/O buffer RAM data bus bidirectional line 3 RD4 19 I/O buffer RAM data bus bidirectional line 4 RD5 20 I/O buffer RAM data bus bidirectional line 5 RD6 21 I/O buffer RAM data bus bidirectional line 6 RD7 22 I/O buffer RAM data bus bidirectional line 7 TEST2 23 I test input 2 DGND3 24 − digital ground 3 TEST1 25 I test input 1 CROUT 26 O clock oscillator output CRIN 27 I clock oscillator input SFSY 28 I serial subcode input frame sync input RCK 29 O serial subcode clock output (active LOW) SUB 30 I serial input for Q-to-W subcode input BCK 31 I serial interface bit clock input V

DDD1

WS 33 I serial interface word clock input DATA 34 I serial data input C2PO 35 I serial interface ﬂag input SDA 36 I/O sub-CPU serial data input/output SCL 37 I sub-CPU serial clock input INT 38 O sub-CPU open-collector interrupt output RESET 39 I power-on reset input (active LOW) SYN 40 I sync signal input from sub-CPU

32 − digital supply voltage 1 (3.3 V)

1996 Apr 25 5

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for

SAA7380

CD-ROM (ELM)

SYMBOL PIN I/O DESCRIPTION

DGND4 41 − digital ground 4 CS1/HEN 42 I host interface enable input (active LOW) HWR 43 I host interface write enable input (active LOW) HRD 44 I host interface read enable input (active LOW) DMACK 45 I DMA acknowledge input IORDY/WAIT/HFBLB 46 O host interface wait output (active LOW); 3-state control SCRST/STEN 47 O host interface status enable output ATAPI sub-CPU reset signal

(active LOW)

DMARQ/DTEN 48 O ATAPI DMA request host interface data enable output (active LOW);

3-state control

IRQ/EOP/HFBC 49 O host interface end of process ﬂag output ATAPI host interrupt request

(active LOW); 3-state control

DDD2

HD0 51 I/O host interface data bus input/output line 0 HD1 52 I/O host interface database input/output line 1 HD2 53 I/O host interface database input/output line 2 HD3 54 I/O host interface data bus input/output line 3 HD4 55 I/O host interface data bus input/output line 4 HD5 56 I/O host interface data bus input/output line 5 HD6 57 I/O host interface data bus input/output line 6 HD7 58 I/O host interface data bus input/output line 7 DGND5 59 − digital ground 5 HD8 60 I/O host interface data bus input/output line 8 HD9 61 I/O host interface data bus input/output line 9 HD10 62 I/O host interface data bus input/output line 10 HD11 63 I/O host interface data bus input/output line 11 HD12 64 I/O host interface data bus input/output line 12 HD13 65 I/O host interface data bus input/output line 13 HD14 66 I/O host interface data bus input/output line 14 HD15 67 I/O host interface data bus input/output line 15 DGND6 68 − digital ground 6 DA0/CMD 69 I host interface data input (active LOW)/command select input host interface

DA1 70 I ATAPI address line input 1 DA2/EJECT 71 I ATAPI address line input 2 CS2/SELRQ 72 I ATAPI chip select input 2 IOCS16 73 O ATAPI 16-bit data select output V

DDD2

RA0 75 O buffer RAM address bus output line 0 RA1 76 O buffer RAM address bus output line 1 RA2 77 O buffer RAM address bus output line 2

50 − digital supply voltage 2 (5 V)

address line 0

74 − digital supply voltage 2 (5 V)

1996 Apr 25 6

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

SYMBOL PIN I/O DESCRIPTION

RA3 78 O buffer RAM address bus output line 3 RA4 79 O buffer RAM address bus output line 4 RA5 80 O buffer RAM address bus output line 5

handbook, full pagewidth

RA0 75

DDD2

IOCS16

SAA7380

CS2/SELRQ

DA2/EJECT 71

DA1 70

DA0/CMD 69

DGND1

RA6 RA7 RA8

RA9 RA10 RA11 RA12 RA13 RA14

RA15/RAS RA16/CAS

RWE

DGND2

RD0

RD1

RD2

RD3

RD4

RD5

RD6

RD7

TEST2

DGND3

RA2

RA5

RA4

RA3

78 1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

RA1

DGND6 68

HD15 67

HD14 66

HD13 65

HD12

HD11

HD10

HD9

HD8

DGND5

HD7

HD6

HD5

HD4

HD3

HD2

HD1

HD0

DDD2

IRQ/EOP/HFBC

DMARQ/DTEN

SCRST/STEN

IORDY/WAIT/HFBLB

DMACK

HRD

HWR

CS1/HEN

DGND4

SAA7380

SUB

TEST1

CRIN

CROUT

SFSY

RCK

BCK

Fig.2 Pin configuration.

1996 Apr 25 7

DDD1

33 WS

DATA

C2PO

SDA

SCL

38 INT

RESET

SYN

MGE189

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

6.1 Pin functions

6.1.1 RA0 External memory address signals.

6.1.2 RA16/CAS External memory RA16 signal if SRAM or, CAS signal if

DRAM.

6.1.3 RA15/RAS External memory RA15 signal if SRAM or, RAS signal if

DRAM.

6.1.4 RWE Write output enable signal for external buffer memory. This

is LOW when the SAA7380 wants to write data into the external memory.

6.1.5 RD0 External buffer memory bidirectional data signals.

TO RA14

TO RD7

SAA7380

6.1.12 C2PO Error flag from the CD decoder. A HIGH indicates that a

byte has not been corrected by the C2 error corrector and therefore is not valid. This is taken into account by the SAA7380 error corrector.

6.1.13 SDA Sub-CPU bidirectional data signal. This signal forms part

of the 3-wire serial interface between the SAA7380 and the sub-CPU.

6.1.14 SCL Sub-CPU sync signal. This signal forms part of the 3-wire

serial interface between the SAA7380 and the sub-CPU. This signal is used to synchronize data transfers between the sub-CPU and the SAA7380.

6.1.15 INT Sub-CPU interrupt signal. This active LOW output signals

to the sub-CPU that the SAA7380 has an interrupt request.

6.1.6 SFSY Frame sync for the Q-to-W subcode, indicates when

P-channel is available by a HIGH-to-LOW transition. Frame 0 is also indicated by no transition on this line.

6.1.7 In response to SFSY going LOW data is clocked into the

SAA7380 before each rising edge using this clock output.

6.1.8 SUB Q-to-W subcode is input in response to

mode or WS in “V4” mode compatible with the SAA7345.

6.1.9 BCK Bit clock for the serial data input from the CD decoder.

6.1.10 WS Word clock for the serial data input from the CD decoder.

6.1.11 DATA Serial data input from the CD decoder. This may be either

S-bus or EIAJ 16-bit format.

RCK

RCK in 3-wire EIAJ

6.1.16 Forcing this input LOW resets the SAA7380.

6.1.17 SYN Sub-CPU clock signal. This signal forms part of the 3-wire

serial interface between the SAA7380 and the sub-CPU. This signal is the sub-CPU driven bit clock used to synchronize the signals on the SDA line.

6.1.18 In the ATAPI mode this is the host chip select 1 address

signal. In the Sanyo and Oak compatibility modes setting this input LOW enables the host interface.

6.1.19 This active LOW signal is the host write request.

6.1.20 This active LOW signal is the host read request.

RESET

CS1/HEN

HWR

HRD

1996 Apr 25 8

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

6.1.21 DMACK This signal is used in the ATAPI and Oak compatibility

modes during DMA transfers. The host pulls this signal LOW in response to a DMARQ request to indicate that it is ready to transfer data.

If this signal is not being used then it must be pulled HIGH for SAA7380 to operate correctly.

6.1.22 In the ATAPI mode this signal is negated to extend the

host transfer cycle of any host register access. It is used in PIO transfers. When IORDY is not negated it is in a high-impedance state.

In the Sanyo compatibility mode the function of this signal depends on the SELRQ input. If SELRQ is HIGH then WAIT is set LOW to extend the host transfer cycle. If SELRQ is LOW then WAIT acts as the DRQ signal in a DMA transfer.

IORDY/WAIT/HFBLB

SAA7380

6.1.25 In the ATAPI mode this active HIGH signal indicates a host

interrupt request. It is asserted when the sub-CPU writes to the ITRG register and is negated when the host reads the status register or writes to the command register.

In the Sanyo compatibility mode this signal is set LOW when the last data byte is transferred to or from the host.

In the Oak compatibility mode this is the Host First Byte Cycle output and is HIGH while the first byte in the pseudo 16-bit DMA transfer is accessed. It should be used to inhibit non-DMA transactions while the first byte is latched.

6.1.26 HD0 These are the bidirectional Host Data signals. In the Sanyo

and Oak compatibility modes HD8 to HD15 are never used.

6.1.27

IRQ/EOP/HFBC

TO HD15

DA0/CMD

In the Oak compatibility mode this signal is the Host First Byte Latch signal. A rising edge on this signal is used to latch the first byte in a pseudo 16-bit DMA read. HFBLB can only be HIGH when pseudo 16-bit DMA transfer mode is selected.

6.1.23 In the ATAPI or Oak compatibility mode this signal is pulled

LOW to reset the sub-CPU in response to a reset command from the host.

In the Sanyo compatibility mode this signal is pulled LOW to signal to the host that status bytes are available for transfer.

6.1.24 In the ATAPI or Oak compatibility mode this signal is

asserted when the SAA7380 is ready to transfer data between the host and itself. In ATAPI single word and Oak DMA transfers this occurs at every word. In ATAPI multi-word DMA transfers this occurs at the start of the transfer.

In the Sanyo compatibility mode this signal is pulled LOW to signal to the host that data bytes are available for transfer.

SCRST/STEN

DMARQ/DTEN

In the ATAPI mode this is the host Data Address 0 signal. In the Sanyo and Oak compatibility modes this input selects between command or data transfers.

6.1.28 DA1 This is the ATAPI Data Address 1 signal.

6.1.29 DA2/ EJECT In the ATAPI mode this is the Data Address 2 signal. In the

Oak compatibility mode this is the door switch input pin. Its state is reflected in the TSTAT register.

6.1.30 CS2/SELRQ In the ATAPI mode this is the Chip Select 2 signal. In the

Oak and Sanyo compatibility mode this is the data transfer mode select input. It is used to select between PIO and DMA transfers.

6.1.31 IOCS16 This open-collector signal is used in the ATAPI mode to

signal to the host that a 16-bit data port has been addressed. It is not activated during DMA transfers.

1996 Apr 25 9

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

7 FUNCTIONAL DESCRIPTION

The SAA7380 is comprised of four main blocks; a CD player interface, an error corrector, a host interface and a memory manager. These four blocks operate in parallel. All receive and send data to the buffer memory via the memory manager. A 36-kbit on-chip SRAM has been incorporated to allow high-speed data read operations for the error corrector.

The SAA7380 performs simultaneous data input buffering, error correction and host data transfer.

7.1 CD-DSP interface and data input

The input data is synchronized, decoded, and written to the buffer RAM. The input data format is software programmable.

The synchronization is achieved using a sync detector and a sync interpolator. The sync detector detects the sync pattern in every sector while the interpolator avoids sync loss when no sync is found. The detector and interpolator can be individually enabled and disabled under software control.

After decoding, each full sector of data (2352 bytes) comprising sync, header, sub-header and parity fields is written to the buffer RAM.

7.2 Error correction and EDC check

Error correction and detection is performed on each sector after it is written to the buffer RAM.

SAA7380

7.3 Host interface

The host interface controls data transfers between the SAA7380 and an external microcontroller. The host interface can be programmed to operate in three modes. In the Sanyo compatibility mode the host interface is functionally compatible with the Sanyo LC89510 block decoder. In the Oak compatibility mode the host interface is functionally compatible with the Oak OTI-012 controller chip in enhanced mode.

In the ATAPI mode the interface meets the ATA Program Interface specification.

7.4 Subcode channel Q-to-W buffering

As well as buffering the main data, the SAA7380 can also be used to buffer R-to-W subcode data in buffer memory. Two buffer modes exist, raw mode and cooked mode. In the raw mode, data is written to an external RAM without any processing being performed. In the cooked mode, the Q-channel data is extracted, the Q-channel CRC is calculated, the R-to-W data is de-interleaved and the residues of each R-to-W frame are calculated. These residues make it easier to correct errors in the data.

7.5 External buffer memory

It is possible to use the SAA7380 with different external RAM memories. From 0 to 128 kbyte SRAMs or to 16-Mbit DRAMs are possible. Memories may be nibble or byte wide (allowing 2, 8 or 16 Mbits). Selection is performed under software control.

The SAA7380 buffers flag and data of sectors to be corrected in a 9-bit, 4096 words on-chip RAM memory. For erasure correction, no external 9-bit memory is required.

The standard error correction algorithm can be programmed, and supports Mode 1 and Mode 2, Form 1 and Form 2 discs.

After error correction, an electronic data check is executed.

When this EDC check is also complete, the sector header and sub-header is written to 8 header registers, and a decode complete interrupt is generated.

The microcontroller can then read the decoder status, the sector header and sub-header and the sector start address from the SAA7380.

1996 Apr 25 10

Unique to the SAA7380 is its ability to work with partly defective DRAMs. The SAA7380 offers the possibility to use a DRAM with bytes in error.

A RAM test is executed under microcontroller control. This RAM test indicates defective segments to the microcontroller which keeps a list of which bad sectors to avoid. The list can be stored in the buffer memory and/or the microcontrollers own memory.

7.6 Sub-CPU registers

This section describes the registers in the SAA7380. The operation of the registers varies depending on whether they are being read from or written to, and the host mode selected.

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for

SAA7380

CD-ROM (ELM)

Table 1 Sub-CPU registers during write

# AR NAME BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0

0 00000 1 00001 IFCTRL CMDIEN DTEIEN DECIEN CMDBK DTWAI STWAI DOUTEN SOUTEN

2 00010 DBCL Data Byte Count register bits 7 to 0 3 00011 DBCH Data Byte Count register bits 15 to 8 4 00100 DACL Data Address Counter register bits 7 to 0 5 00101 DACH Data Address Counter register bits 15 to 8 6 00110 DTRG Data Transfer Trigger register 7 00111 DTACK Data Transfer Acknowledge register 8 01000 WAL Write Address register bits 7 to 0

9 01001 WAH Write Address register bits 15 to 8 10 01010 CTRL0 DECEN lookahead E01RQ AUTOQ ERAMRQ WRRQ ECCRQ ENCODE 11 01011 CTRL1 SYIEN SYDEN DSCREN COWREN MODRQ FORMRQ MBCKRQ SHDREN 12 01100 PTL Block Pointer register bits 7 to 0 13 01101 PTH Block Pointer register bits 15 to 8 14 01110 15 01111 16 10000 DACHH mem Data Address Counter register bits 20 to 16 17 10001 WAHH Write Address register bits 20 to 16 18 10010 PTHH Block Pointer register bits 20 to 16 19 10011 SUB_L Subcode Address register bits 7 to 0 20 10100 SUB_H Subcode Address register bits 9 and 8 21 10101 22 10110 INCNF IISmode div 1 div 0 QWmode QWon QWcook RAM test 0 23 10111 MEMS 0 PRIORITY 0 RFRSH WIDTH STATIC CACHE 24 11000 ASTAT ATAPI Status register 25 11001 ITRG Host Interrupt Trigger register 26 11010 ADRADR ATAPI Drive Address register 27 11011 ASAMT ATAPI SAM TAG register 28 11100 DTCTR res. DMAMODE UDMA SUBIEN RDRV TRANT 29 11101 ADRSEL ATAPI Drive Select register 30 11110 AINTR ATAPI Interrupt Reason register 31 11111 AERR ATAPI Error register

ADATA/ SBOUT

RESET reserved HSEL

ATAPI Data register/Status Byte Output register

1996 Apr 25 11

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for

SAA7380

CD-ROM (ELM)

Table 2 Sub-CPU registers during read

# AR NAME BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0

0 00000

1 00001 IFSTAT CMDI DTEI DECI SUBI DTBSY

2 00010 DBCL Data Byte Count register bits 7 to 0

3 00011 DBCH Data Byte Count register bits 15 to 8

4 00100 HEAD0 Minutes/ File Number

5 00101 HEAD1 Seconds/ Channel Number

6 00110 HEAD2 Frames/ Submode

7 00111 HEAD3 Mode/ Coding Information

8 01000 PTL Block Pointer register bits 7 to 0

9 01001 PTH Block Pointer register bits 15 to 8 10 01010 WAL Write Address register bits 7 to 0 11 01011 WAH Write Address register bits 15 to 8 12 01100 STAT0 CRCOK ILSYNC NOSYNC LBLK USHORT SBLK ERR UCEB 13 01101 STAT1 MINERR SECERR BLKERR MODERR SH0ERR SH1ERR SH2ERR SH3ERR 14 01110 STAT2 RMOD3 RMOD2 RMOD1 RMOD0 MODE FORM RFORM1 RFORM2 15 01111 STAT3 VALST CBLK 16 10000 PTHH Block Pointer register bits 20 to 16 17 10001 WAHH Write Address register bits 20 to 16 18 10010 SUB_L Subcode Address register bits 7 to 0 19 10011 SUB_H Subcode Address register bits 9 and 8 20 10100 21 10101 22 10110 23 10111 24 11000 25 11001 HCON Oak Host Conﬁguration register 26 11010 ACMD ATAPI Command register 27 11011 ASAMT ATAPI SAM TAG register 28 11100 ADCTR ATAPI Device Control register 29 11101 ADRSEL ATAPI Drive Select register 30 11110 AINTR ATAPI Interrupt Reason register 31 11111 AFEAT ATAPI Features register

APCMD/

COMIN

ATAPI packet command data/command input register

SRSTI/

STBSY

DTEN STEN

1996 Apr 25 12

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

7.7 Register Descriptions

7.7.1 SBOUT/ADATA This is a 12 byte FIFO used to transfer data from the

sub-CPU to the host. In the Sanyo and Oak compatibility mode writing to this

register starts a status byte transfer. In this mode if the SOUTEN bit in the IFCTRL register has been set to logic 1, writing to the SBOUT register sets the STBSY bit to logic 0. If the STWAI bit is set to logic 0, immediately set LOW to inform the host computer that the status byte is ready to be read from.

If the STWAI bit is set to logic 1 and the DTEN bit in the IFSTAT register is also set to logic 1, both the STEN pin and the STBSY will go LOW. However, if the STWAI bit is set to logic 0, and theDTEN bit is set to logic 0, thenSTEN is held HIGH until the DTEN bit goes HIGH, thereafter it goes LOW.

STEN is

SAA7380

7.7.2 COMIN/ APCMD During the ATAPI mode this register is used to read the

program command sent by the host. The program command can only be received if the appropriate mode has been selected (see Table 22) and a data transfer has been started (see DTRG register).

During Sanyo and Oak compatibility modes this register is a 12 byte FIFO which is used to transfer commands from the host to the sub-CPU. If reading this register empties the command FIFO then CMDI is set to logic 1 and further reads from the register will return FFH.

7.7.3 IFCTRL The IFCTRL register provides control over the host

interface. Resetting the chip will clear all bits. In the ATAPI mode, only, bits 7 to 5 have any effect.

Table 3 IFCTRL register bits

BIT NAME DESCRIPTION

7 CMDIEN Enable bits for CMDI, DTEI and DECI. These are interrupt masks, enabling/disabling the 6 DTEIEN 5 DECIEN

1 DOUTEN Data output enable. DOUTEN enables/disables data transfers. When set to logic 0, all

0 SOUTEN Status output enable. SOUTEN enables/disables status byte transfers. When set to

CMDBK Command break enable. If set to logic 0 then the command break function is enabled

DTWAI Data transfer WAIT enable. Setting this bit to logic 0 enables the data WAIT function.

STWAI Status byte transfer WAIT enable. This bit acts in a similar way to the DTWAI bit except it

sub-CPU interrupt pin. They do not affect the bits in the IFSTAT register. If set to logic 1, the corresponding interrupt is enabled. It should be noted that these masks do not clear the interrupts.

and if the host writes to the COMIN FIFO then any data or status byte transfers in progress will be terminated. If set to logic 1 then this operation is disabled. The data transfer interrupt DTEI is not generated by a command break.

The data WAIT function allows the SAA7380 to delay hardware execution of the data transfer until a status byte transfer has been completed. Disabling the data WAIT function allows data transfers to take place independently of status byte transfers.

controls the status WAIT function. The status WAIT function allows the SAA7380 to delay hardware execution of the status transfer until a data byte transfer has been completed. Disabling the data WAIT function allows status transfers to take place independently of data transfers.

data transfers in progress are aborted.

logic 0, the status FIFO register is reset to empty and all status byte transfers in progress are aborted.

1996 Apr 25 13

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for

SAA7380

CD-ROM (ELM)

7.7.4 IFSTAT The IFSTAT register indicates the state of the host interface. In the ATAPI mode, only bits 7 to 2 have any meaning.

Table 4 IFSTAT register bits

BIT NAME DESCRIPTION

1 0

CMDI Command interrupt. In the ATAPI mode this bit is asserted when the host has written

to the ATAPI command register (see ACMD register) and the drive is selected. It is also asserted when the host writes the execute drive diagnostic command (90H) to the ATAPI command register, regardless of whether the drive is selected. It is negated when the sub-CPU reads the ACMD register. In the Sanyo and Oak compatibility modes this bit is asserted while there are command bytes waiting in the COMIN FIFO. It is negated when the COMIN FIFO is empty.

DTEI Data transfer end interrupt. This bit is asserted at the end of data transfer. It is

negated when the sub-CPU writes to the DTACK register. If the ATAPI mode is selected this bit is also asserted when a program command has been received and after a sub-CPU memory transfer.

DECI Decoder interrupt. This bit is asserted when a new sector is available. It is negated by

reading the STAT3 register.

SUBI Subcode interrupt. This bit is asserted when a new subcode is available. It is negated

by reading the SUB_H register.

DTBSY Data transfer busy.This bit indicates if a data transfer is taking place. It is asserted by

writing to the DTRG register and is negated at the end of the transfer.

SRSTI/STBSY SRST bit interrupt/status transfer busy. In the ATAPI mode this bit is asserted when

the host writes to the ATAPI device control register and sets the SRST bit. It is negated when the sub-CPU reads the ADCTR register. It should be noted that if this bit is asserted in the ATAPI mode then the sub-CPU interrupt will also be asserted. The SRSTI interrupt cannot be disabled. In the Sanyo and Oak compatibility modes this bit indicates if a status byte transfer is taking place. It is asserted by writing to the

SBOUT register and is negated when the host has emptied the status FIFO. DTEN Data transfer and status transfer. These bits reflect the state of the DTEN and STEN STEN

pins in the Sanyo and Oak compatibility modes. They are updated at the end of a

host read or write.

7.7.5 DBCL AND DBCH The Data Byte Counter is used by the sub-CPU to control

the number of bytes that are transferred in a data transfer. In the ATAPI mode all 16 bits are available while in the Sanyo and Oak compatibility modes only 15 bits are available with bit 7 of DBCH indicating the state of DTEI (see Table 4). During memory-to-host data transfers the data byte counter is decremented after every host read. During host-to-memory data transfers the data byte counter is decremented as data is written into external buffer memory.

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7.7.6 DACL, DACH AND DACHH This 21-bit write-only register is used to specify the

external buffer address of the first byte of the data block to be transferred to the host.

Once the address has been set, it is incremented automatically as successive bytes are transferred with the host. It should be noted that pointer operation is asynchronous from host read/write operation. For this reason, counter increments are not coincident with host transfer operations.

Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

Bit 7 of the DACHH register specifies which memory is accessed. If the bit is clear then the address refers to the external memory, if the bit is set then the address refers to the 4 kbyte internal memory. The internal memory should not be accessed during error correction.

This register should be written to before each data transfer because its value will be undefined at the end of the previous transfer.

7.7.7 PTL, PTH This register holds a 21-bit pointer to the external buffer

memory address of the head of the current data block after correction.

The SAA7380 defines the minute byte in the header to be at the head of the block, and the 12 sync bytes at the tail of the block. Each block contained in the buffer is taken to be 2352 bytes.

The controller can transfer the decoded block back to the host by copying the address of this register to the DACL, DACH and DACHH pointers after a decoder interrupt.

When the WRRQ bit in the CTRL0 register is set to logic 1, this pointer is updated at the sync signal of every 2352 byte clocks.

7.7.8 WAL, WAH These registers contain a 21-bit address of where raw data

from the drive is written to the external buffer memory. The pointer is automatically incremented during data transfer. The pointer should only be read while drive data writes to the buffer are disabled. If WAHH is written to while drive data write is enabled, then the new WA value will be used

AND PTHH

AND WAHH

SAA7380

for the first byte of the next sector. The new pointer value is temporarily stored in the PT register. This cannot be read after WA has been written to.

7.7.9 DTRG Writing to this register starts a data transfer. The data

written is discarded.

7.7.10 DTACK Writing to this register clears the

written is discarded.

7.7.11 HEAD0, HEAD1, HEAD2 These registers are used to hold the header and the

sub-header data of the current block. To read the header data set, the SHDREN bit in the

CTRL1 register is set to logic 0; to read the sub-header data, SHDREN is set to logic 1.

If sub-header is selected, the registers will normally hold data from bytes 20 to 23. However, if the error flag for one of these bytes is set, then the byte is taken from the first sub-header field. (bytes 16 to 19.)

The error flags for header and sub-header can be read from the STAT1 register. No error correction is performed on header or sub-header.

Header and sub-header registers are valid directly after decoder interrupt, and as long as the VALST bit in the STAT3 register is LOW. In all write modes they contain information on the block whose header is pointed to by PTL, PTH and PTHH.

DTEI interrupt. The data

AND HEAD3

Table 5 HEAD registers

SHDREN REGISTER CONTENTS

0 HEAD0 MINUTES (byte12) 0 HEAD1 SECONDS (byte 13) 0 HEAD2 FRAMES (byte 14) 0 HEAD3 MODE (byte 15) 1 HEAD0 FILE NUMBER (byte 16 or 20) 1 HEAD1 CHANNEL NUMBER (byte 17 or 21) 1 HEAD2 SUBMODE NUMBER (byte 18 or 22) 1 HEAD3 CODING INFORMATION (byte 19 or 23)

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Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

7.7.12 CTRL0 Resetting the chip sets all the bits in this register to logic 0.

Table 6 CTRL0 register

BIT NAME FUNCTION

7 DECEN Disable decoding = 0; Enable decoding = 1. This bit enables/disables decoding

functions. Disabling the decoding functions also disables the decoder interrupt.

6 lookahead At interrupt PT, header refer to current block = 0; At interrupt PT, header refer to next

block = 1. When this bit is set to logic 1 at decoder interrupt, CMA and header registers will give information on the next block instead of on the current block. The lookahead mode was included to provide support for bad RAMs, and to give the CPU better control on the blocks it wants to read.

5 E01RQ Disable error correction of bytes = 0; Enable correction of CIRC mis-corrections = 1.

Setting this bit to logic 0 instructs the error corrector not to correct bytes flagged as reliable by the CIRC error corrector.

4 AUTORQ Disable automatic error correction = 0; Enable automatic error correction = 1. Requests

automatic extraction of form bit during Mode 2 correction from sub-header data.

3 ERAMRQ Disable erasure ﬂag use = 0; Enable erasure ﬂag use = 1. When set to logic 1, the

SAA7380 will enable the use of erasure flag information for error correction. When set to logic 0, the SAA7380 will disable the use of erasure flag information for error correction. Use of erasure flags must be disabled when the CD-DSP does not output erasure flags and when the internal buffer RAM is disabled (which is necessary for repeat correction).

2 WRRQ Disable data writes to the buffer and PTL updates = 0; Enables data writes to the buffer

and PTL updates = 1. This bit enables/disables writes from the CD drive into the buffer. It also enables/disables pointer (PTL, PTH and PTHH) updates each time a block is received. When WRRQ is set to logic 1, data write will start from the first byte of the next block onwards. When WRRQ is set to logic 0, repeat correction is enabled. With WRRQ set to logic 0, the internal buffer RAM is disabled.

1 ECCRQ Disable ECC correction = 0; Enable ECC correction = 1. When ECCRQ is set to logic 1

the blocks received by the SAA7380 will be error corrected before a decoder interrupt is generated. When ECCRQ is set to logic 0 no corrections are performed. The algorithm used is a QD, PD, QE, PE algorithm. In a first step, errors are corrected; in a second step, erasures are corrected. Correction data is read from the on-chip 36 kbit buffer memory.

0 ENCODE Normal operation = 0; Test mode, do not use = 1, this bit must always be set to logic 0.

SAA7380

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Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

Table 7 Error correction modes

DECEN lookahead WRRQ ECCRQ decoder mode

0 X X X decoder disable; note 1 1000monitor only 1001repeat correction 1010write only 1011real-time correct, normal mode 1110write only, lookahead 1111real-time correct, lookahead

Note

1. Where X = don’t care.

7.7.13 CTRL1 The reset function clears all the flags in this register.

Table 8 CTRL1 register bits

SAA7380

BIT NAME FUNCTION

7 SYIEN Disable sync interpolation = 0; Enable sync interpolation = 1. Enabling SYIEN prevents

loss of synchronization when an error occurs in a sync pattern during data read.

6 SYDEN Disable sync detection = 0; Enable sync detection = 1. Enabling SYDEN synchronizes

the decoder with the sync pattern detected in the input data.

5 DSCREN Descramble disable (audio) = 0; Descramble enable = 1. This bit enables/disables

descrambling. Setting this bit to logic 0 allows reading of raw data on disc, even audio signals. This bit should be set to logic 1 for CROM data.

4 COWREN CRC with error correction disabled = 0; Detection errors are corrected = 1. This bit

enables/disables rewriting of error bytes in the buffer during error correction. Setting

the bit to logic 0 allows CRC checks without error correction. 3 MODRQ Mode 1 request = 0; Mode 2 request = 1. This bit discriminates Mode 1/Mode 2. 2 FORMRQ Form 1 request = 0; Form 2 request = 1. This bit discriminates Mode 2/Form 1 and

Mode 2/Form 2. 1 MBCKRQ Disable mode check function = 0; Enable mode check function = 1. If the mode

specified in the mode byte does not correspond with the raw data mode bit and this bit

is set to logic 1 then error correction and detection is disabled. 0 SHDREN Header data on registers Head0 to Head3 = 0; Sub-header data on registers

Head0 to Head3 = 1. This bit toggles header and sub-header data between registers

HEAD0 to HEAD3.

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Philips Semiconductors Preliminary speciﬁcation

Error correction and host interface IC for CD-ROM (ELM)

7.7.14 STAT0 Resetting the chip clears all bits in this register.

Table 9 STAT0 register bits

BIT NAME FUNCTION

7 CRCOK Cyclic redundancy check not OK = 0; Cyclic redundancy check OK = 1. Set by the

EDC in accordance with the results of the CRC check. 6 ILSYNC Sync pattern detected at word count 0 to 1174 or 1176 onwards = 1. This bit is set to

logic 1 if the sync pattern in the incoming data is detected between word counts

0 and 1174 or 1176 to infinity, and the decoder has been retimed. Due to the

presence of the cache RAM, it is necessary to stop error correction also when long

blocks have been detected. 5 NOSYNC Sync pattern inserted by sync interpolator not coincident with data sync = 1. This bit

is set to logic 1, if the word counter reaches 1175 and no sync pattern has been

detected in the input data. It indicates that the sync interpolator circuit inserted a

sync. 4 LBLK With SYIEN = 0, no sync found. Data block size has been extended = 1. This bit is

set to logic 1, if the sync interpolator was switched off, and if the sync interpolator

indicated that sync insertion was necessary. This condition causes the block length to

be extended. 3 Reserved 2 SBLK Short block indication = 1. This bit is set to logic 1 if the decoder is not retimed when

a sync pattern is detected in an incorrect word location, and is ignored while the

SYDEN bit is set to logic 0. 1 ERABLK One or more bytes of the block are ﬂagged with C2 ﬂags = 1. This bit is set to logic 1

if one or more bytes of the current block contain erasures as indicated by the C2PO

input. 0 UCEBLK Uncorrectable errors in block = 1. This bit is set to logic 1 when one or more bytes of

the current block remain in error after the error correction process.

SAA7380

7.7.15 STAT1 Resetting the chip clears all bits in this register. The bits in this register indicate the reliability of data in the HEAD0 to HEAD3 registers. Bits MINERR, SECERR,

BLKERR and MODERR indicate errors in the minutes, seconds, frames and mode bytes in the header of the current block. Bits SH0ERR to SH3ERR indicate errors in the respective bytes in the sub-header.

Table 10 STAT1 register bits

BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0

MINERR SECERR BLKERR MODER SH0ERR SH1ERR SH2ERR SH3ERR

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