STw5093

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To read-back status information from STw5093, the first byte of the appropriate instruction is strobed in during

the first CS- pulse, as defined in Table 1. CS- must be set low for a further 8 CCLK cycles, during which data is

shifted out of the CO pin on the falling edges of CCLK.

When CS- is high, CO pin is in the high impedance Tri-state, enabling CO pins of several devices to be multi-

plexed together.

Thus, to summarise, 2 byte READ and WRITE instructions may use either two 8-bit wide CS- pulses or a single

16 bit wide CS- pulse.

1.1.8 Control channel access to PCM interface:

It is possible to access the B channel previously selected in Register CR1 in the case of companded code only.

A byte written into Control Register CR3 will be automatically transmitted from DX output in the following frame

in place of the transmit PCM data.

A byte written into Control Register CR2 will beautomatically sent through the receive path to the Receive am-

plifiers.

In order to implement a continuous data flow from the Control MICROWIRE interface to a B channel, it is nec-

essary to send the control byte on each PCM frame.

flow from a B channel to MICROWIRE interface, it is necessary to read register CR2 at each PCM frame.

1.1.9 AUXCLK usage:

The Auxiliary clock AUXCLK is only used to keep active the tone and buzzer generation functions to the Ear-

piece or to the Extra amplifier outputs when the Master Clock MCLK is not available, and there is no voice ac-

tivity both in transmit and receive channels. When AUXCLK is selected, the PCM digital interface is inactive (DX

in tristate and DR is not read). The selection between AUXCLK and MCLK is done by bit SLC in register CR1The

input frequency of AUXCLK is selected via bits F1 and F0 of register CR0 as for the MCLK signal.

1.1.10REMOCON 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 (7 of CR10). If enabled, this function is active also when

the STw5093 is in Power-down state.

At REMIN input an high level 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 (6 of CR10):

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

of 50ms maximum.

if RLM = 1 (Latched Mode) the information stored in bit RDL (4 of CR10) is seen at REMOUT.When a

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

power on reset and can also be reset writing CR10.

The REMOUT output polarity can be inverted setting bit ROI (5 of CR10):the pressed button information is pre-

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

2.0 PROGRAMMABLE FUNCTIONS

The programmable functions are configured by writing to a number of registers using a 2-byte write cycle. Most

of these registers can also be read-back for verification. Byte one is always register address, while byte two is

Data. Table 1 lists the register set and their respective adresses.