WM8803CDTSLASHV datasheet(23/45 Pages) WOLFSON

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WM8803

PP Rev 1.1 September 2003

status data delimiter bit 1. In this case, the parity error flag used for data recognized as PCM data will

not be output.

OTHER ERRORS

Even when ERROR has gone low, the WM8803 always acquires bits 24 to 27 (sampling frequency)

of the channel status and compares the current data with that of the previous block. If any

differences are found, ERROR is immediately set to the high level and the state is handled as a PLL

lock error.

Similarly, when FLIMIT is set to restrict fs input range and the input fs calculation results are reflected

in the error flags, fs calculation results are compared continuously. If a disparity occurs in the data,

ERROR will immediately go high, and the state will be handled as a PLL lock error.

ERROR OCCURRENCE PROCESSING

This section describes the data processing performed when an error occurs. When up to 8

consecutive input parity errors occur and if the transmitted data is PCM audio data, the data is

replaced with the corresponding left and right channel data from the immediately preceding frame. If

the transmitted data is non-PCM data, the error data is output without modification. Non-PCM data is

based on data that was detected before the input parity error that occurred, and is data for which the

channel status bit 1 non-PCM data detection bit is “1”.

The output data is muted when 9 or more consecutive parity errors, or a PLL lock error, occur.

For the channel status output when a parity error occurs, the data for the previous block is retained.

DATA AND

DETECTION FLAGS

PLL LOCK

ERROR

INPUT PARITY

ERROR (A)

INPUT PARITY

ERROR (B)

INPUT PARITY

ERROR (C)

SDATO output pin

Previous data

Output

Input fs calculation

Output

Channel status data

Previous data

Sub-code Q data

Output

—

Table 10 Data Processing when Errors Occur

Notes:

Input parity error (A): When 9 or more consecutive parity errors occur

Input parity error (B): When up to 8 consecutive parity errors occur in audio data

Input parity error (C): When up to 8 consecutive parity errors occur in non-PCM burst

data

The figure below presents an example of the data processing performed when a parity error occurs.

ERROR

SDATAO

R-ch

Previous data value

Input Data

LRCLK

An error occurs a single time

Muted after 9 or more

consecutive errors

L-ch R-ch ….

Previous data value

R-2

L-2

R-0

L-1

R-0

L-0

L-2 R-2 L-2 R-2 L-2 R-2 L-2 R-2

L-4

R-3

L-3

R-2

L-2

R-1

R-4 L-5 R-5 L-6 R-6 L-7 R-7 L-8 R-8

L-1

Figure 18 Data Processing Example Following a Parity Error (When PCM data is

received)

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