www.ti.com

STANDALONE MODE CONFIGURATION

Sampling Mode

Audio Data Format

Soft Mute Function

PCM4104-EP

SBAS419 – JUNE 2007

Standalone mode is selected by forcing the MODE input (pin 8) low. Standalone mode operation provides a

subset of the functions available in Software mode, while providing an option for a simplified control model.

Standalone configuration is accomplished by either hardwiring or driving a small set of input pins with external

logic or switches. Standalone mode functions include sampling mode and audio data format selection, an

all-channel soft mute function, and digital de-emphasis filtering. The following paragraphs provide a brief

description of each function available when using Standalone mode.

The sampling mode is selected using the FS0 (pin 28) and FS1 (pin 29) inputs. A more detailed discussion of

the sampling modes was provided in an earlier section of this data sheet. Table 2 summarizes the sampling

mode configuration for Standalone mode.

Table 2. Sampling Mode Configuration

FS1

FS0

SAMPLING MODE

0

0

Single Rate

0

1

Dual Rate

1

0

Quad Rate

1

1

- Not Used -

The audio data format is selected using the FMT0 (pin 25), FMT1 (pin 26), and FMT2 (pin 27) inputs. A detailed

discussion of the audio serial port operation and the corresponding data formats was provided in the Audio

Serial Port section on page 19. For Standalone mode, the LRCK polarity is always normal, while the serial audio

data is always sampled on the rising edge of the BCK clock. Table 3 shows the audio data format configuration

for Standalone mode.

Table 3. Audio Data Format Configuration

FMT2

FMT1

FMT0

AUDIO DATA FORMAT

0

0

0

24-bit left justified

0

0

1

24-bit I2S

0

1

0

TDM with zero BCK delay

0

1

1

TDM with one BCK delay

1

0

0

24-bit right justified

1

0

1

20-bit right justified

1

1

0

18-bit right justified

1

1

1

16-bit right justified

The MUTE input (pin 10) may be used in either the Standalone or Software modes to simultaneously mute the

four output channels. The soft mute function slowly ramps the digital output attenuation from its current setting to

the mute level, minimizing or eliminating audible artifacts. Table 4 summarizes MUTE function operation.

Table 4. Mute Function Configuration

MUTE

ANALOG OUTPUTS

0

On (mute disabled)

1

Muted

24

Submit Documentation Feedback