Datasheet
SAM9G45 [DATASHEET]
Atmel-6438O-ATARM-SAM9G45-Datasheet_08-Dec-15
888
38. Image Sensor Interface (ISI)
38.1 Description
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 Table 38-3 on page 891).
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.
38.2 Embedded Characteristics
ITU-R BT. 601/656 8-bit mode external interface support
Support for ITU-R BT.656-4 SAV and EAV synchronization
Vertical and horizontal resolutions up to 2048 x 2048
Preview Path up to 640*480
Support for packed data formatting for YCbCr 4:2:2 formats
Preview scaler to generate smaller size image
Table 38-1. I/O Description
Signal Dir Description
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