• Digital Compact Cassette (DCC) optimized error
correction
• Programmable symbol synchronization strategy for tape
input data
• Microcontroller control of capstan servo possible during
playback and recording
• Frequency and phase regulation of capstan servo
during playback
• Choice of Dynamic Random Access Memory (DRAM)
and Static Random Access Memory (SRAM) types for
system Random Access Memory (RAM)
• Scratch pad RAM for microcontroller in system RAM
• Integrated interface for Precision Adaptive Sub-band
Coding (PASC) data bus
• Three wire microcontroller ‘L3’ interface
• Protection against invalid auxiliary data
• Seamless joins between recordings.
GENERAL DESCRIPTION
The SAA3323 performs the drive processor function in the
DCC system. This function is built up of digital equalizer,
error correction and tape formatting functions. The digital
equalizer is intended for use with DCC read amplifiers
TDA1318 or TDA1380. The tape formatting and error
correction circuit is intended for use with PASC ICs
SAA2003 and SAA2013, and write amplifiers TDA1319 or
TDA1381.
ORDERING INFORMATION
TYPE NUMBER
SAA3323H80TQFP80
SAA3323GP80QFP80
Note
1. When using reflow soldering it is recommended that the Dry Packing instructions in the
Pocketbook”
May 19942
are followed. The pocketbook can be ordered using the code 9398 510 34011.
PINSPIN POSITIONMATERIALCODE
(1)
(1)
PACKAGE
plasticSOT315-1
plasticSOT318-2
“Quality Reference
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
BLOCK DIAGRAM
handbook, full pagewidth
SBDIR
SBMCLK
SBEF
SBDA
SBCL
SBWS
SAA3323
SUB-BAND
2
I S
INTERFACE
DIGITAL-
TO-ANALOG
CONVERTER
PHASE
LOCKED
LOOP
TAPE
INPUT
BUFFER
ERROR
CORRECTOR
ZERO
CROSSING
INTERNAL DATA BUS
RAM
INTERFACE
8116
(1)
FIR
IIR
AUXILIARY
ENVELOPE
DETECTION
ANAEYE
RDSYNC
(2)
ANALOG
TO-DIGITAL
CONVERTER
EQUALIZER
MODULE
TAPE
OUTPUT
BUFFER
CONTROL
INTERFACE
RDMUX
BIAS
V
ref(p)
V
ref(n)
TCLOCK
WDATA
SPEED
URDA
RESET
SLEEP
L3REF
L3DATA
(1) FIR = Finite Impulse-Response.
(2) IIR = Infinite Impulse-Response.
OEN
WEN
D0 to D7
A0 to A10
A11 to A16
Fig.1 Block diagram.
PINO1
PINO2
PINI
L3INT
L3CLK
L3MODE
MLB761
May 19943
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
PINNING
SYMBOL
PIN
DESCRIPTIONTYPE
(1)
QFP80TQFP80
SBWS179word select for sub-band PASC interfaceI/O (1 mA)
SBCL280bit clock for sub-band PASC interfaceI/O (1 mA)
SBDA31data line for sub-band PASC interfaceI/O (1 mA)
SBDIR42direction line for sub-band PASC interfaceO (1 mA)
SBMCLK53master clock for sub-band PASC interfaceI
URDA64unreliable dataO (1 mA)
L3MODE75mode line for L3 interfaceI
L3CLK86bit clock line for L3 interfaceI
L3DATA97serial data line for L3 interfaceI/O (2 mA)
L3INT108L3 interrupt outputO (1 mA)
V
V
DD1
SS1
119digital supply voltageS
1210digital groundS
L3REF1311L3 bus timing referenceO (1 mA)
RESET1412reset SAA3323I
SLEEP1513sleep mode selection of SAA3323I
CLK24161424.576 MHz clock inputI
AZCHK1715channel 0 and channel 7 azimuth monitorO (1 mA)
MCLK18166.144 MHz clock outputO (1 mA)
TEST31917TEST3 output; do not connectO (1 mA)
ERCOSTAT2018ERCO status, for symbol error rate measurementsO (1 mA)
OEN2119output enable for RAMO (2 mA)
A10/
RAS2220address SRAM; RAS DRAMO (2 mA)
V
V
DD2
SS2
2321digital supply voltageS
2422digital groundS
D72523data SRAMI/O (4 mA)
D62624data SRAMI/O (4 mA)
D52725data SRAMI/O (4 mA)
D42826data SRAMI/O (4 mA)
D32927data SRAM; data DRAMI/O (4 mA)
D23028data SRAM; data DRAMI/O (4 mA)
D13129data SRAM; data DRAMI/O (4 mA)
V
V
A115553address SRAMO (2 mA)
SPEED5654Pulse Width Modulation (PWM) capstan control output for deck O
PINO25755Port expander output 2O
(1 mA)
t
(1 mA)
t
WDATA5856serial output to write amplifierO (1 mA)
TCLOCK59573.072 MHz clock output for tape I/OO (1 mA)
V
SS5
V
DD5
TEST26260TEST mode select; do not connectI
RDMUX6361analog multiplexed input from read amplifierI
V
ref(p)
V
ref(n)
SUBSTR6664substrate connectionI
BIAS6765bias current for ADCI
V
SSA
V
DDA
ANAEYE7068analog eye pattern outputO
6058digital groundS
6159digital supply voltageS
6462ADC positive reference voltageI
6563ADC negative reference voltageI
6866analog groundS
6967analog supply voltageS
pd
A
A
A
A
A
A
RDSYNC7169synchronization output for read amplifierO (1 mA)
V
V
DD6
SS6
7270digital supply voltageS
7371digital groundS
CHTST17472channel test pin 1O (1 mA)
CHTST27573channel test pin 2O (1 mA)
TEST07674TEST mode select; do not connectI
TEST17775TEST mode select; do not connectI
1. I = input; IA= analog input; Ipd= input with pull-down resistance; I/O = bidirectional; O = output; OA= analog output;
Ot= 3-state output; S = supply.
A simplified block diagram of the SAA3323 is shown in
Fig.1.
DCC drive processing
The SAA3323 provides the following functions for the DCC
drive processing.
LAYBACK MODES
P
• Analog-to-digital conversion
• Tape channel equalization
• Tape channel data and clock recovery
• 10-to-8 demodulation
• Data placement in system RAM
• C1 and C2 error correction decoding
• Interfacing to sub-band serial PASC interface
• Interfacing to microcontroller for SYSINFO and AUX
data
• Capstan control for tape deck.
R
ECORD MODES
• Interfacing to sub-band serial PASC interface
• C1 and C2 error correction encoding
• Formatting for tape transfer
• 8-to-10 modulation
• Interfacing to microcontroller for SYSINFO and AUX
data
• Capstan control for tape deck, programmable by
microcontroller.
S
EARCH MODE
Table 1 Basic modes of TFE module.
MODEEXPLANATION
DPAPaudio and SYSINFO (main data) play;
AUX play
DPARaudio and SYSINFO (main data) play;
AUX record
DRARaudio and SYSINFO (main data) record;
AUX record
REGISTERS
TFE
The TFE module has 8 writable and 5 readable registers
that are accessible via the L3 interface, one write register
(CMD) and four read registers (STATUS0 to STATUS3)
which are directly addressable, the other registers are
indirectly addressable via commands sent to the CMD
register. The registers are named as shown in Table 2.
• Detection and interpretation of AUX envelope
information
• AUX envelope counting
• Search speed estimation.
Tape Formatting and Error (TFE) correction module
The TFE module has 3 basic modes of operation as shown
in Table 1.
May 19949
Note
1. The 4 LSBs of register ‘SET3’ set RAM type (RType)
and RAM timing (RTim). See Table 3.
For normal operation the 4 MSBs of register ‘SET3’
should be logic 0.
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
Table 3 RAM settings by register SET3.
RAMREGISTER SET3
RTYPE 0bit 0
RTYPE 1bit 1
RTim 0bit 2
RTim 1bit 3
TFE
DATA STREAMS
The TFE module has three read/write data streams that
are accessible via the L3 interface and they are shown in
Table 4.
Table 5 TFE commands.
NAME
RDSPEED00000000read SPEED register
LDSET000010000load new TFE settings register 0
LDSET100010001load new TFE settings register 1
LDSET200010010load new TFE settings register 2
LDSET300010011load new TFE settings register 3
LDSPDDTY00010101load SPDDTY register
LDBYTCNT00010111load BYTCNT register
LDRACCNT00011000load RACCNT register
RDAUX00100000read AUXILIARY information
RDSYS00100001read SYSINFO
RDDRACYZ100010read RAM data bytes (8 bits) from quarter YZ
RDWDRACYZ100011read RAM data words (12 bits) from quarter YZ
WRAUX00110000write AUXILIARY information
WRSYS00110001write SYSINFO
WRDRACYZ110010write RAM data bytes (8 bits) to quarter YZ
WRWDRACYZ110011write RAM data words (12 bits) to quarter YZ
COMMAND BYTE
76543210
Table 4 TFE data streams.
DATA STREAM NAMEREAD/WRITE
SYSINFOR/W
AUXINFOR/W
Scratch pad RAMR/W
COMMANDS’
TFE ‘
These are the commands that need to be sent to the TFE
in order to access the indirectly accessible registers and
the data streams, see Table 5.
EXPLANATION
Digital equalizer module
The digital equalizer module has 2 basic modes of
operation as shown in Table 6.
Table 6 Basic modes of equalizer module.
MODEEXPLANATION
Playmain data and AUX channels are
equalized
Searchonly AUX channel is processed; AUX
envelope information is processed
May 199410
DIGITAL EQUALIZER REGISTERS
The digital equalizer module has 9 write only, 3 read only
and 1 read/write register(s) that are accessible via the
L3 interface, one write register (CMD) and 2 read registers
(STATUS0 and STATUS1) which are directly addressable,
the other registers are indirectly addressable via
commands sent to the CMD register. The registers are
named as shown in Table 7.
WRCOEF00110000 write FIR coefficients to the digital equalizer buffer bank
RDCOEF00100000 read FIR coefficients from the digital equalizer active bank
LDCOEFCNT00010011 load FIR coefficient counter
LDFCTRL00010100load filter control register
LDT1SEL00010110 load CHTST1 pin selection register
LDT2SEL00010111 load CHTST2 pin selection register
LDTAEYE00011000 load ANAEYE channel selection register
LDAEC00011001 load AEC counter
RDAEC00100010 read AEC counter
RDSSPD00100100 read SEARCH speed register
LDINTMSK00010010load interrupt mask register
LDDEQ3SET00010000load digital equalizer settings register
LDCLKSET00010001load PLL clock extraction settings register
DATA STREAMS
The digital equalizer module has one write only and one
read only data stream that are accessible via the
L3 interface and they are shown in Table 8.
Table 8 Digital equalizer data streams.
DATA STREAM NAMEREAD/WRITE
FIR coefficients to buffer bankW
FIR coefficients from active bankW
IGITAL EQUALIZER “COMMANDS”
D
These are the commands that need to be sent to the digital
equalizer in order to access the indirectly accessible
registers and the data streams.
EXPLANATION
Table 10 Filter control register.
BIT7654321 0
Meaning−−−µCS
Default00001011
Note
1. µCS is a microcontroller controlled coefficient bank switch. This causes the filter coefficients to be activated at a time
that is safe for the digital equalizer, i.e. at the end of the FIR program and that the complete value of coefficient
number 9 has been received.
May 199411
(1)
SH1SH0Reserved
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
Table 11 SH1 and SH2 (FIR output scaling).
SH
10
00FIR mod 256
01
10
11
EFFECT ON FIR OUTPUT
FIR
mod 256
---------2
FIR
mod 256
---------4
FIR
mod 256
---------8
Transfer of FIR coefficients
For the main data channels (tracks 0 to 7) there are
10 coefficients (taps) each of 8 bits, where all of the data
channels make use of the same coefficients. The
addresses for the main data coefficients 0 to 9 are
0to9
There are ten coefficients (taps) each of 8 bits for the aux
channel (CHAUX). The addresses for the auxiliary
coefficients 0 to 9 are 16 to 25
respectively.
dec
respectively.
dec
There are 2 banks of coefficients for both the aux and the
main data channels, namely the ‘buffer’, and the ‘active’
banks. The microcontroller writes only to the ‘buffer’
banks, and reads only from the ‘active’ banks.
The microcontroller can poll the digital equalizer status bit
BKSW to see when the switch occurs. BKSW starts life
LOW, goes HIGH as a result of the bank switching and
goes LOW as result of the complete value of a main data
coefficient being received by the digital equalizer.
The microcontroller sets µCS HIGH before sending the
new set of aux or main data coefficients, the digital
equalizer resets it once the bank switch occurs.
The actual FIR coefficients that are used are a function of
the tape head, read amplifier and type of tape (i.e.
pre-recorded or own recorded) used, such information is
outside of the scope of this data sheet.
Coefficient address counter (COEFCNT)
This 5 bit counter is used to point to the FIR coefficient to
be transferred to or from the digital equalizer.
Table 12 Coefficient address counter.
BIT7654321 0
Meaning−−−CC4CC3CC2CC1CC0
Default00000000
Pin explanations and interfacing to other hardware
RESET
This is an active HIGH input which resets the SAA3323
and brings it into its default mode, DPAP. This reset does
not affect the contents of the FIR filter coefficients in the
digital equalizer. This should be connected to the system
reset, which can be driven by the microcontroller. The
duration of the reset pulse should be at least 15 µs.
SLEEP
This pin is an active HIGH input which puts the SAA3323
in a low power consumption SLEEP mode. This pin should
be connected to the DCC SLEEP signal, which can be
driven by the microcontroller. The CLK24 clock may be
stopped and the VREFP and VREFN inputs brought to
ground while the SAA3323 is in ‘sleep’ mode to further
reduce power consumption. When recovering from sleep
mode, the SLEEP pin should be taken LOW and the
SAA3323 reset.
CLK24
This is the 24.576 MHz clock input and should be
connected directly to the SAA2003 (pin CLK24).
Sub-band serial PASC interface connections
The timing for the sub-band serial PASC interface is given
in Figs 5 to 7.
May 199412
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
handbook, full pagewidth
SBCL(in)
SBWS(in)
SBDA(in)
SBCL(in)
SBWS(in)
SBDA(in)
SBCL(in)
SBWS(in)
SBDA(in)
bit number
2 x t 40 ns
MCLK
40 ns
1514131211109876543210
31302928272625242322212019181716
V
IH
V
OH
V
IH
V
OH
V
IH
V
OH
MGB381
Fig.5 Sub-band serial PASC interface timing; DRAR mode.
May 199413
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
handbook, full pagewidth
SBCL(out)
SBWS(out)
SBDA(out)
SBEF(out)
SBCL(out)
SBWS(out)
SBDA(out)
SBEF(out)
SBMCLK(in)
SBCL(out)
SBWS(out)
SBDA(out)
SBDA(out)
60 ns
7 ns
7 ns
1514131211109876543210
31302928272625242322212019181716
bit number
V
IH
V
IL
V
OH
V
OL
V
OH
V
OL
V
OH
V
OL
V
OH
V
OL
MGB382
Fig.6 Sub-band serial PASC interface timing in play modes; DRPMAS = logic 1.
May 199414
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
handbook, full pagewidth
SBCL(in)
SBWS(in)
SBDA(out)
SBEF(out)
SBCL(in)
SBWS(in)
SBDA(out)
SBEF(out)
SBCL(in)
SBWS(in)
SBDA(out)
SBDA(out)
2 x t 40 ns
MCLK
t (40 85) ns
MCLK
t (40 40) ns
MCLK
40 ns
1514131211109876543210
31302928272625242322212019181716
bit number
V
IH
V
IL
V
IH
V
IL
V
OH
V
OL
V
OH
V
OL
MGB383
Fig.7 Sub-band serial PASC interface timing in play modes; DRPMAS = logic 0.
SBMCLK
This is the sub-band master clock input for the sub-band
serial PASC interface. The frequency of this signal is
nominally 6.144 MHz. When the SAA3323 is used with
SAA2003 this pin is tied to ground, and the TFE settings
bit ‘DRPMAS’ set to logic 1.
SBDIR
This output pin is the sub-band serial PASC bus direction
signal, it indicates the direction of transfer on the sub-band
serial PASC bus. This pin connects directly to the SBDIR
pin on the SAA2003. The transfer directions are shown in
Table 13.
Table 13 PASC bus transfer directions.
SBDIRDIRECTION
1SAA3323 to SAA2003 transfer (audio play)
0SAA2003 to SAA3323 transfer (audio record)
SBCL
This input/output pin is the bit clock line for the sub-band
serial PASC interface to the SAA2003. When used with
SAA2003 this pin is input only. It has a nominal frequency
of 768 kHz.
SBWS
This input/output pin is the word select line for the
sub-band serial PASC interface to the SAA2003. When
used with SAA2003 this pin is input only. It has a nominal
frequency of 12 kHz.
SBDA
This input/output pin is the serial data line for the sub-band
serial PASC interface to the SAA2003.
SBEF
This active HIGH output pin is the error-per-byte line for
the sub-band serial PASC interface to the SAA2003.
May 199415
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
URDA
This active HIGH output pin indicates that the main data
(audio), the SYSINFO and the AUXILIARY data are NOT
usable, regardless of the state of the corresponding
reliability flags. The state of this pin is reflected in the
URDA bit of STATUS byte 0, which can be read by the
microcontroller. This pin should be connected directly to
handbook, full pagewidth
SNUM
SBWS
L3REF
'FIRST BYTE"
SBDA
0
the URDA pin of the SAA2003. URDA goes active as a
result of a reset, a mode change from mode DRAR to
DPAP, or if the SAA3323 has had to re-synchronize with
the incoming data from tape.
The position of the first sub-band serial PASC bytes in a
tape frame is shown in Figs 8 and 9.
1
MGB384
byte 0
byte 1 byte 2
Fig.8 Position of first sub-band serial PASC bytes in a tape frame in DPAP/DPAR mode.
handbook, full pagewidth
SNUM
SBWS
L3REF
'FIRST BYTE'
SBDA
30
byte 0 byte 1 byte 2
Fig.9 Position of first sub-band serial PASC bytes in a tape frame in DRAR mode.
MGB385
May 199416
Philips SemiconductorsPreliminary specification
Drive processor for DCC systemsSAA3323
RAM connections
The SAA3323 has been designed to operate with DRAMs
and SRAMs. Suitable DRAMs are 64K × 4-bit or
256K × 4-bit configurations operating in page mode, with
an access time of 80 to 100 ns. The timing for read, write
and refresh cycles for DRAMs is shown in Figs 10 to 12.
The timing for SRAMs is shown in Figs 13 to 19.
For fast SRAMs: (these values are subject to verification
during characterization in). The conditions (most critical at
the required VDD) are shown in Table 14.
Table 14 Fast SRAM conditions.
CONDITION
Write pulse durationt
Data set-up to rising
Write cycle timeT
Read access timet
(1)
≤ 140 ns
W
WENtsu≤ 72 ns
≤ 200 ns
cy
≤ 240 ns
ACC
TIME
Note
1. The SAA3323 should work in: RType = ‘01’;
RTim = ‘00’ mode.
A9/
CAS
When SAA3323 is used with SRAM this output pin is
Address line 9, and should be connected directly to the
corresponding address pin on the SRAM. When SAA3323
is used with DRAM this output pin is the column address
strobe (active LOW), it connects directly to the column
address strobe pin of the DRAM.
A10/
RAS
When SAA3323 is used with SRAM this output pin is
Address line 10, and should be connected to the
corresponding address pin of the SRAM. When SAA3323
is used with DRAM this output pin is the row address
strobe (active LOW), it connects directly to the row
address strobe pin of the DRAM.
OEN
This output pin is the output enable (active LOW) for the
RAM, it connects directly to the output enable pin of the
RAM.
WEN
This output pin is the write enable (active LOW) for the
RAM, it connects directly to the write enable pin of the
RAM.
TO A8
A0
When SAA3323 is used with DRAM these output pins are
the multiplexed column and row address lines. When the
64K × 4-bit DRAM is used, pins A0 to A7 should be
connected to the DRAM address input pins, and pin A8
should be left unconnected. When using the 256K × 4-bit
DRAM the address pins A0 to A8 should be connected to
the address input pins of the DRAM.
When SAA3323 is used with SRAM these are the lower
address pins and should be connected directly to the
SRAM address pins.
A11
This output pin is the an address pin for the SRAM and
when SRAM is used they should be connected directly to
the address pins of the SRAM. When DRAM is used this
pin should not be connected.
A10 AND A12 TO A16
These output pins are the upper address pins for the
SRAM and when SRAM is used they should be connected
directly to the address pins of the SRAM. When DRAM is
used or when the small SRAM is used all or some of these
pins become available as Port expander outputs.
May 199417
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