SAA7373 Datasheet, PDF (19/60 Pages) NXP Semiconductors – Digital servo processor and Compact Disc decoder CD7

Philips Semiconductors
Digital servo processor and Compact Disc
decoder (CD7)
Product specification
SAA7373
Table 7 Bit assignment
FUNCTION
Control
Reserved mode
Category code
Clock accuracy
Remaining
BITS
0 to 3
4 to 7
8 to 15
28 to 29
16 to 27 and
30 to 191
DESCRIPTION
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
set by register A; 10 = level I; 00 = level II; 01 = level III
always zero
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
before the digital filter. The output is switched active LOW
when silence has been detected for at least 250 ms, or if
mute is active, or in CD ROM modes. Two modes are
available which can be selected by register C:
1 pin kill: KILL active LOW indicates silence detected on
both left and right channels.
2 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
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.
1998 Jul 06
19