STW5094AD datasheet(14/51 Pages) STMICROELECTRONICS

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STw5094A

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2.16 Control Interface (I2C I

⁄ F)

The I2C I

⁄ F is used to program the device by writing and reading the control registers (see Fig. 14 and

15). The interface is I2C bus compatible, being the STw5094A a Slave device. SDA is the bidirectional

open-drain data pin and SCL is the input clock pin. The Device Address is E2 hex. for writing and E3 hex.

for reading.

The interface has an internal address register that keeps the current address of the control register to be

read or written. At each write access of the interface the address register is loaded with the data of the

is possible to access the interface in 2 modes: single-byte mode in which the address and data of a single

is specified and all the following bytes exchanged are the data of successive address registers starting

from the one specified (in multi-byte mode the internal address counter restart from register 0 after the last

to the device on the I2Cbus.

The Control interface can be used both in power-up and power-down state.

2.17 Master clock in FM mode and tone only modes

In FM mode and in Tone Only mode the Master Clock of the device can be selected to be AUXCLK, MCLK

or AMCK writing bits CFM in CR21. The Auxiliary clock AUXCLK can be used when the Audio mode clock

AMCK and the Voice mode clock MCLK are not available. AUXCLK and MCLK frequency selection is

done with bits F in CR0.

2.18 REMOCON function

The REMOCON (Remote Control) function can be used to detect the status of an headset button. The

REMOCON function is enabled by setting bit REN in CR17. If enabled, this function is active also when

the STw5094A is in power-down state. The REMOUT/OCK pin is the output pin for the REMOCON func-

tion only if OCE =0 in CR17 (Section 2.15).

A High level at REMIN input is detected as a non pressed button, while a low level is detected as a pressed

button. The "Pressed Button" information can be treated in 2 ways depending on bit RLM in CR17:

-if RLM = 0 (Transparent mode) the information at REMIN is seen at REMOUT/OCK after a debounce

time of 50ms maximum;

-if RLM = 1 (Latched Mode) the information stored in bit RDL in CR17 is seen at REMOUT/OCK. RDL

is set after a debounce time of 50ms maximum when a low level at REMIN is detected. RDL is reset

with power on initialization and can also be reset writing 0 in bit RDL.

The REMOUT/OCK output polarity can be inverted setting bit ROI in CR17: the pressed button information

is presented at REMOUT/OCK output as a logic 1 if bit ROI = 0. If ROI = 1 the polarity is inverted.

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