Advertisement
Philips Semiconductors
CMOS digital decoding IC with RAM for
Compact Disc
W
SAA7345;
RITING DATA TO
The same command can be repeated several times (e.g. for fade function) by applying extra RAB pulses as shown in
Fig.6.
RAB
(microcontroller)
CL
(microcontroller)
DA
(microcontroller)
DA (SAA7345)
Note that CL must stay HIGH between RAB pulses.
R
EADING STATUS INFORMATION FROM
There are several internal status signals which can be made available on the DA line (Table 1).
Table 1 Internal status signals.
SIGNAL
SUBQREADY-I
LOW if new subcode word is ready in Q-channel register.
MOTSTART1
HIGH if motor is turning at 75% or more of nominal speed.
MOTSTART2
HIGH if motor is turning at 50% or more of nominal speed.
MOTSTOP
HIGH if motor is turning at 12% or less of nominal speed.
PLL Lock
HIGH if Sync coincidence signals are found.
V1
Follows input on V1 pin.
V2
Follows input on V2 pin.
MOTOR-OV
HIGH if the motor servo output stage saturates.
The status signal to be output is selected by status control register (address 0010). The timing for reading the status
signal is shown in Fig.7.
Status read operation sequence
Write appropriate data to register 0010 to select required status signal.
With RAB LOW; set CL LOW.
Set RAB HIGH; this will instruct the SAA7345 to output status signal on DA.
1998 Feb 16
REPEAT MODE
A3
A2
A1
Fig.6 Microcontroller WRITE timing; repeat mode.
SAA7345
A0
D3
D2
D1
high impedance
DESCRIPTION
8
Product specification
D0
MGA380 - 1
SAA7345
Advertisement
