Philips SAA7345

1998 Feb 16 14

Philips Semiconductors Product speciﬁcation

CMOS digital decoding IC with RAM for

Compact Disc SAA7345

Note

1. Standby modes = CL, DA and RAB; normal operation.

a) MISC, SCLK, WCLK, DATA, CL11 and DOBM; 3-state.

b) CRIN, CROUT, CL16 and CLA; normal operation.

c) V1, V2, V3, V4 and V5; normal operation.

d) MOTO1 and MOTO2 - in standby 2 ‘CD-PAUSE’; normal operation.

e) MOTO1 and MOTO2 - in standby 1 ‘CD-STOP’; held LOW in PWM mode; 3-state in PDM mode.

Versatile pins interface 1 1 0 1 0 0 0 0 4-line motor (using V4, V5)

X X 0 1 Q-to-W subcode at V4

X X 1 0 V4 = 0

X X 1 1 V4 = 1 Reset

0 1 X X de-emphasis signal at V5

10 X X V5=0

1 1 X X V5 = 1 Reset

Error corrector

The error corrector carries out t = 2, e = 0 error corrections

on both C1 (32 symbol) and C2 (28 symbol) frames. Four

symbols are used from each frame as parity symbols. The

strategy t = 2, e = 0 means that the error corrector can

correct two erroneous symbols per frame and detect all

erroneous frames.

The error corrector also contains a flag controller. Flags

are assigned to symbols when the error corrector cannot

ascertain if the symbols are definitely good. C1 generates

output flags which are read (after de-interleaving) by C2,

to help in the generation of C2 output flags.

The C2 output flags are used by the interpolator for

concealment of non-correctable errors. They are also

output via the EBU signal (DOBM) and the MISC output

with I2S for CD-ROM applications.

The flags output pin CFLG provides information on the

state of all error correction and concealment flags.

Audio functions

DE-EMPHASIS AND PHASE LINEARITY

When de-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 linearity of

the digital oversampling filter to ≤±1° within the band

0 to 16 kHz.

DIGITAL OVERSAMPLING FILTER

The SAA7345 contains a 2 to 4 times oversampling filter.

The filter specification of the 4 ×oversampling filter is

given in Table 2 and shown in Fig.12.

These attenuations do not include the sample and hold at

the 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

sinewave inputs (0 to 20 kHz).