BelaSigna R262

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17

Boot Control, Hardware Configuration and

Digital Control

At power−on−reset, BelaSigna R262 will normally

execute the application stored in ROM. During the boot

process, BelaSigna R262 will read voltage levels on four

different pins, which will determine the algorithm and

hardware configuration that will be executed. All the

configuration options are described later in this section; the

four pins are CLOCK_SEL, BOOT_SEL, CHAN_SEL and

ALPHA_SEL.

The BOOT_SEL pin controls the booting methods of

BelaSigna R262. The signal on this pin is sampled by

BelaSigna R262 during its booting process using a

low−speed A/D converter (LSAD). Based on the actual

voltage that the chip will read on this pin, it will

automatically select a particular booting configuration, as

described in Table 9.

Preset

Voltage Level

Boot Method

Description

0−2

0.65 − 1.00 V

External Boot Mode

In this mode, BelaSigna R262 will not run the ROM based applica-

tion. It will start looking for an SPI EEPROM to bootload a custom

bootload a custom application; and lastly, if neither of the two previ-

ous operations to find an EEPROM are successful, it will enter a

tom application (e.g. a baseband controller).

3

0.50 − 0.63 V

Active Mode

Talking distance selectable from

Near− to Far−Talk

(50 cm to 500 cm)

The noise reduction algorithm is running and can be configured for

talking distances between 50 cm (Near−Talk) and 5 m (Far−Talk)

4

0.36 − 0.49 V

Active Mode

Talking distance selectable from

Close− to Far−Talk

(5 cm to 500 cm)

The noise reduction algorithm is running and can be configured for

talking distances between 5 cm (Close−Talk) and 5 m (Far−Talk)

5

0.22 − 0.35 V

Active Mode

Talking distance selectable from

Close− to Near−Talk

(5 cm to 100 cm)

The noise reduction algorithm is running and can be configured for

talking distances between 5 cm (Close−Talk) and 1 m (Near−Talk)

6

0.08 − 0.21 V

Bypass Diagnostic Mode

1 kHz sine wave play−out

BelaSigna R262 outputs a pure tone on the two output channels.

This sine wave has a frequency of 1 kHz and an output level of

12 dB below full scale.

7

0 − 0.07 V

Bypass Diagnostic Mode

Full stereo passthrough

BelaSigna R262 simply copies the input signals to the outputs.

4. For more details on the various operating modes of BelaSigna R262, please consult the BelaSigna R262 Communications and Configuration

Guide.