Datasheet

 2017 Microchip Technology Inc. DS60001516A-page 693
SAM9G20
38. Image Sensor Interface (ISI)
38.1 Overview
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).
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.
Figure 38-1: ISI Connection Example
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
Image Sensor Image Sensor Interface
data[11..0]
ISI_DATA[11..0]
CLK
ISI_MCK
PCLK
ISI_PCK
VSYNC
HSYNC
ISI_VSYNC
ISI_HSYNC