AT91SAM9G45-EKES Atmel, AT91SAM9G45-EKES Datasheet - Page 897

• Manufacturer Part Number: AT91SAM9G45-EKES
• Description: KIT EVAL FOR AT91SAM9G45
• Manufacturer: Atmel
• Series: AT91SAM Smart ARMr
• Type: MCUr

Specifications of AT91SAM9G45-EKES

• Contents: Board
• Processor To Be Evaluated: SAM9G45
• Data Bus Width: 32 bit
• Interface Type: I2C, SPI, UART
• Maximum Operating Temperature: + 50 C
• Minimum Operating Temperature: - 10 C
• Operating Supply Voltage: 1.8 V to 3.3 V
• For Use With/related Products: AT91SAM9G45
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q4626953

39.4
39.4.1
6438F–ATARM–21-Jun-10
Functional Description
Data Timing
The Image Sensor Interface (ISI) supports direct connection to the ITU-R BT. 601/656 8-bit
mode compliant sensors and up to 12-bit grayscale sensors. It receives the image data stream
from the image sensor on the 12-bit data bus.
This module receives up to 12 bits for data, the horizontal and vertical synchronizations and the
pixel clock. The reduced pin count alternative for synchronization is supported for sensors that
embed SAV (start of active video) and EAV (end of active video) delimiters in the data stream.
The Image Sensor Interface interrupt line is connected to the Advanced Interrupt Controller and
can trigger an interrupt at the beginning of each frame and at the end of a DMA frame transfer. If
the SAV/EAV synchronization is used, an interrupt can be triggered on each delimiter event.
For 8-bit color sensors, the data stream received can be in several possible formats: YCbCr
4:2:2, RGB 8:8:8, RGB 5:6:5 and may be processed before the storage in memory. The data
stream may be sent on both preview path and codec path if the bit ISI_CDC in the ISI_CTRL is
one. To optimize the bandwidth, the codec path should be enabled only when a capture is
required.
In grayscale mode, the input data stream is stored in memory without any processing. The 12-bit
data, which represent the grayscale level for the pixel, is stored in memory one or two pixels per
word, depending on the GS_MODE bit in the ISI_CFG2 register. The codec datapath is not
available when grayscale image is selected.
A frame rate counter allows users to capture all frames or 1 out of every 2 to 8 frames.
The two data timings using horizontal and vertical synchronization and EAV/SAV sequence syn-
chronization are shown in
In the VSYNC/HSYNC synchronization, the valid data is captured with the active edge of the
pixel clock (ISI_PCK), after SFD lines of vertical blanking and SLD pixel clock periods delay pro-
grammed in the control register.
The ITU-RBT.656-4 defines the functional timing for an 8-bit wide interface.
There are two timing reference signals, one at the beginning of each video data block SAV
(0xFF000080) and one at the end of each video data block EAV(0xFF00009D). Only data sent
between EAV and SAV is captured. Horizontal blanking and vertical blanking are ignored. Use of
the SAV and EAV synchronization eliminates the ISI_VSYNC and ISI_HSYNC signals from the
interface, thereby reducing the pin count. In order to retrieve both frame and line synchronization
properly, at least one line of vertical blanking is mandatory.
Figure 39-3
and
Figure
39-4.
AT91SAM9G45
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