SAA7335 Datasheet, PDF (18/36 Pages) NXP Semiconductors – DSP for CD and DVD-ROM systems

Philips Semiconductors
DSP for CD and DVD-ROM systems
Preliminary specification
SAA7335
Table 4 EBU word format
WORD
Sync
Auxiliary
Error flags
BITS
0 to 3
4 to 7
4
Audio sample
Validity flag
User data
Channel status
Parity bit
8 to 27
28
29
30
31
FUNCTION
−
not used; normally zero
CFLG error and interpolation flags when bit 3 of EBU control register is set
to logic 1
first 4 bits not used (always zero)
valid = logic 0
used for subcode data (Q-to-W)
control bits and category code
even parity for bits 4 to 30
Table 5 EBU channel status
WORD
Consumer/professional
Control
BITS
0
1 to 4
Reserved
Category code
Reserved
Clock accuracy
Remaining
5 to 7
8 to 15
16 to 27
28 to 29
30 to 191
FUNCTION
always zero
copied from bits 3 to 0 of register OUTPUT2, normally should be set to a
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
always zero
CD; bit 8 = logic 1, all other bits = logic 0
always zero
set by OUTPUT2 control register bits 5 and 4; 00 = level II, 01 = level III
always zero
Spindle motor control
The spindle motor speed is controlled by a fully integrated
digital servo. Address information from the internal
±8 frame FIFO and disc speed information are used to
calculate the motor control output signals.
Several output modes are supported:
1. Pulse density, 1-line,
2. Pulse density, 2-line (true complement output) (cannot
be used with tachometer control)
3. PWM output, 2-line.
The modes are selected via the motor output configuration
register.
PULSE DENSITY MODE
In the pulse density mode the motor output (pin MOTO1)
is the pulse density modulated motor output signal. A 50%
duty cycle corresponds with the motor not actuated, higher
duty cycles mean acceleration, lower mean braking.
In this mode, the MOTO2 signal is the inverse of the
MOTO1 signal. Both signals change state only on the
edges of a internal clock signal.
Possible application diagrams are shown in Fig.13.
PWM MODE, 2-LINE
In the PWM mode the motor acceleration signal is put in
pulse-width modulation form on the MOTO1 output and
the motor braking signal is pulse-width modulated on the
MOTO2 output.
Figure 14 illustrates the PWM mode timing and Fig.15
illustrates a typical PWM mode application diagram.
1997 Aug 11
18