NJU8721

- 4 -

(6) System Control

(6-1) Standby

Standby functions by “L” level input to the STBY terminal. In busy of Standby, conditions of digital audio

format set, attenuation level, de-emphasis, and attenuator operation time are kept and output terminals of

(6-2) Control Mode Set

A control mode as shown below is selected by the MODE terminal.

MODE

Control Method

Function

Terminals

0

Parallel

Digital Audio interface Format Set

F0, F1, F2

1

Serial

Control Register serial data input

DATA, REQ, SCK

Parallel

: Digital Audio Interface Format is set directly by using F0, F1, and F2 terminals.

Serial

: NJU8721 is controlled serial input data by 3-wire serial interface using DATA, REQ, and

SCK terminals

By this setting, the function of F0/DATA, F1/REQ, and F2/SCK are changed.

Refer to

 (8-5)F0,F1,F2  about function of F0, F1, and F2 terminals.

Refer to

 (8)Control Register  about function of DATA, REQ, and SCK terminals.

(6-3) Mute

Mute functions by “L” signal into the MUTE terminal. In busy of mute, a current attenuation value

becomes -

∞ by internal digital attenuator. And MUTE is stopped by “H” signal into the MUTE terminal, the

attenuation value returns from -

∞ to previous value.

MUTE

Attenuation Level

0

-

∞

1

Set Value

-

∞

-

∞

Set Value

MUTE

MCK

Attenuation Value

Set Value

Figure 2. Mute Timing