Atmel Evaluation Kit AT91SAM9G25-EK AT91SAM9G25-EK Data Sheet

993

SAM9G25 [DATASHEET]

11032D–ATARM–10-Mar-2014

The Image Sensor Interface (ISI) connects a CMOS-type image sensor to the processor and provides image capture in 
various formats. It does data conversion, if necessary, before the storage in memory through DMA.

The ISI supports color CMOS image sensor and grayscale image sensors with a reduced set of functionalities.

In grayscale mode, the data stream is stored in memory without any processing and so is not compatible with the LCD 
controller.

Internal FIFOs on the preview and codec paths are used to store the incoming data. The RGB output on the preview path 
is compatible with the LCD controller. This module outputs the data in RGB format (LCD compatible) and has scaling 
capabilities to make it compliant to the LCD display resolution (See 

).

Several input formats such as preprocessed RGB or YCbCr are supported through the data bus interface.

It supports two modes of synchronization:

1.

The hardware with ISI_VSYNC and ISI_HSYNC signals

2.

The International Telecommunication Union Recommendation ITU-R BT.656-4 Start-of-Active-Video (SAV) and 
End-of-Active-Video (EAV) synchronization sequence.

Using EAV/SAV for synchronization reduces the pin count (ISI_VSYNC, ISI_HSYNC not used). The polarity of the 
synchronization pulse is programmable to comply with the sensor signals.

ISI_VSYNC

IN

Vertical Synchronization

ISI_HSYNC

IN

Horizontal Synchronization

ISI_DATA[11..0]

IN

Sensor Pixel Data

ISI_MCK

OUT

Master Clock Provided to the Image Sensor

ISI_PCK

IN

Pixel Clock Provided by the Image Sensor

Image Sensor

Image Sensor Interface

data[11..0]

ISI_DATA[11..0]

CLK

ISI_MCK

PCLK

ISI_PCK

VSYNC

HSYNC

ISI_VSYNC

ISI_HSYNC