VL6522

Detailed description

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4.1.14

Automatic frame rate control

When enabled, the automatic frame rate control will reduce the frame rate in low light levels

to improve image quality. By default the minimum frame rate that the device will use is 5 fps.

4.1.15

Fade to black

Using programmable levels the microprocessor will fade the output signal to black. This

ensures that under the darkest conditions, when the image is not of sufficient quality, the

device will output black. This operation is achieved by scaling the RGB to the YCbCr matrix.

4.2

Audio data pipeline (ADP)

The audio block contains functions allowing the capture and processing of audio data from

an external microphone. The processed data is then written into an external FIFO which is

in turn read by the USB control.

4.2.1

Audio overview

The audio processing blocks used in the VL6522 ADP are listed below:

●

Microphone amplifier with programmable gain

●

16-bit sigma delta ADC

●

●

Variable sample rate at both 8 and 16 bits

●

Interface to external async audio FIFO

●

ICB register bank to provide control and status

4.3

ICB system control

4.3.1

System control overview

In the VL6522, the embedded microcontroller has five main functions:

●

USB management

●

Power management

●

SFP management

●

Auto exposure control (AEC)

The task of the exposure control is to ensure that all scenes are correctly exposed to provide

a good level of contrast. In normal operation the VL6522 will use hardware-generated

statistics to determine appropriate exposure settings for a particular scene and adjust the

system accordingly to give a correctly exposed image.

●

Auto white balance (AWB)

Using hardware-generated statistics the microcontroller adjusts the gains applied to the

individual color channels in order to achieve a correctly color balanced image.

b.

The Automatic Gain Control is disabled by default