SAA7377 Datasheet, PDF (13/56 Pages) NXP Semiconductors – Digital servo processor and Compact Disc decoder CD7

Philips Semiconductors
Digital servo processor and Compact Disc
decoder (CD7)
Product specifications
SAA7377
Table 2 Output flags
F1 F2 F3 F4 F5 F6 F7 F8
DESCRIPTION
0 x x x x x x x no absolute time sync
1 x x x x x x x absolute time sync
x 0 0 x x x x x C1 frame contained no errors
x 0 1 x x x x x C1 frame contained 1 error
x 1 0 x x x x x C1 frame contained 2 errors
x 1 1 x x x x x C1 frame uncorrectable
x x x 0 0 x x 0 C2 frame contained no errors
x x x 0 0 x x 1 C2 frame contained 1 error
x x x 0 1 x x 0 C2 frame contained 2 errors
x x x 0 1 x x 1 C2 frame contained 3 errors
x x x 1 0 x x 0 C2 frame contained 4 errors
x x x 1 1 x x 1 C2 frame uncorrectable
x x x x x 0 0 x no interpolations
x x x x x 0 1 x at least one 1 sample interpolation
x x x x x 1 0 x at least one hold and no interpolations
x x x x x 1 1 x at least one hold and one 1 sample interpolation
7.6.2 C2FAIL
The C2FAIL pin indicates that invalid data has occurred on
the I²S-bus interface. However, due to the structure of the
corrector it is impossible to determine which byte has
failed. C2FAIL will go LOW for 140 µs when invalid data is
detected, this data may then occur 15 ms before or after
the pin is activated.
7.7 Audio functions
7.7.1 DE-EMPHASIS AND PHASE LINEARITY
When pre-emphasis is detected in the Q-channel
subcode, the digital filter automatically includes a
de-emphasis filter section. When de-emphasis is not
required, a phase compensation filter section controls the
phase of the digital oversampling filter to ≤ ±1° within the
band 0 to 16 kHz. With de-emphasis the filter is not phase
linear.
If the de-emphasis signal is set to be available at V5,
selected via register D, then the de-emphasis filter is
bypassed.
These attenuations do not include the sample-and-hold at
the external DAC output or the DAC post filter. When using
the oversampling filter, the output level is scaled −0.5 dB
down, to avoid overflow on full-scale sine wave inputs
(0 to 20 kHz).
Table 3 Filter specification
PASS BAND
0 to 9 kHz
19 to 20 kHz
−
−
−
−
−
−
−
STOP BAND
−
−
24 kHz
24 to 27 kHz
27 to 35 kHz
35 to 64 kHz
64 to 68 kHz
68 kHz
69 to 88 kHz
ATTENUATION
≤0.001 dB
≤0.03 dB
≥25 dB
≥38 dB
≥40 dB
≥50 dB
≥31 dB
≥35 dB
≥40 dB
7.7.2 DIGITAL OVERSAMPLING FILTER
The SAA7377 contains a 2 to 4 times oversampling IIR
filter. The filter specification of the 4 times oversampling
filter is given in Table 3.
1998 Jul 06
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