Maxim MAX9777, MAX9778 manual Address BIT Name Value Description, Register Address

Stereo 3W Audio Power Amplifiers with Headphone Drive and Input Mux

MAX9777/MAX9778

Write Data Format There are three registers that configure the MAX9777: the MUTE register, SHDN register, and control register. In write data mode (R/W = 0), the register address and data byte follow the device address (Figure 7).

MUTE Register The MUTE register (01hex) is a read/write register that sets the MUTE status of the device. Bit 3 (MUTEL) of the MUTE register controls the left channel; bit 4 (MUTER) controls the right channel. A logic-high mutes the respective channel; a logic-low brings the channel out of mute.

SHDN Register The SHDN register (02hex) is a read/write register that controls the power-up state of the device. A logic-high

in bit 0 of the SHDN register shuts down the device; a logic-low turns on the device. A logic-high is required in bits 2 to 7 to reset all registers to their default settings.

Control Register The control register (03hex) is a read/write register that determines the device configuration. Bit 1 (IN1/IN2) con- trols the input multiplexer, a logic-high selects input 1; a logic-low selects input 2. Bit 2 (HPS_D) controls the headphone sensing. A logic-low configures the device in automatic headphone detection mode. A logic-high dis- ables the HPS input. Bit 3 (GAINA/B) controls the gain- select multiplexer. A logic-low selects GAINA. A logic- high selects GAINB. GAINA/B is ignored when HPS_D =

0.Bit 4 (SPKR/HP) selects the amplifier operating mode when HPS_D = 1. A logic-high selects speaker mode, and a logic-low selects headphone mode.

S

ADDRESS

WR

ACK

COMMAND

ACK

DATA

ACK

P

7 BITS

8 BITS

8 BITS

1

I2C SLAVE ADDRESS.

REGISTER ADDRESS.

REGISTER DATA

SELECTS DEVICE.

SELECTS REGISTER TO BE

WRITTEN TO.

S

ADDRESS

WR

ACK

COMMAND

ACK

S

ADDRESS

WR

ACK

DATA

P

7 BITS

8 BITS

7 BITS

8 BITS

1

I2C SLAVE ADDRESS.

REGISTER ADDRESS.

I2C SLAVE ADDRESS.

DATA FROM

SELECTS DEVICE.

SELECTS REGISTER

SELECTS DEVICE.

SELECTED REGISTER

TO BE READ.

Figure 7. Write/Read Data Format Example

Table 3. MAX9777 MUTE Register Format

REGISTER			0000 0001
ADDRESS
BIT	NAME	VALUE		DESCRIPTION
7	X	Don’t Care		—
6	X	Don’t Care		—
5	X	Don’t Care		—
4	MUTER	0*		Unmute right channel
		1		Mute right channel
3	MUTEL	0*		Unmute left channel
		1		Mute left channel
2	X	Don’t Care		—
1	X	Don’t Care		—
0	X	Don’t Care		—

*Default state.

Table 4. MAX9777 SHDN Register Format

REGISTER ADDRESS			0000 0010
BIT	NAME	VALUE		DESCRIPTION
7	RESET	0*		—
		1		Reset device
6	RESET	0*		—
		1		Reset device
5	RESET	0*		—
		1		Reset device
4	RESET	0*		—
		1		Reset device
3	RESET	0*		—
		1		Reset device
2	RESET	0*		—
		1		Reset device
1	X	Don’t Care		—
0	SHDN	0*		Normal operation
		1		Shutdown

*Default state.

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