Only For Training And Service Purposes - LG GD580 Service Manual

3. Technical brief
E. Camera Data Interface (CDI) Block
The camera data interface (CDI) block is designed to support a range of still image camera
modules. An 8-bit parallel bus supports data transfer from the camera module to the CDI.
The pixel clock is an output clock from the camera module to the CDI and qualifies the data on
the parallel bus. One byte of data is captured on each rising edge of the pixel clock. CDI
allows the pixel clock to be in the range of 100 kHz to 16 MHz.
The horizontal synchronization line is an input from the camera module and defines one scan-
line of image data. The horizontal synchronization line can be programmed to be active high
or low. The vertical synchronization line is an input from the camera module and defines one
image frame (image height) of data. The vertical synchronization line can be programmed to
be active high or low.
The frame rate can be adjusted by skipping frames and various interrupts are used to inform
the application CPU regarding the progress of incoming images and potential errors. The
normal data format on the data bus is YUV 4:2:2 (raw binary image data) according to the
CCIR-656 standard. A function within the CDI can be programmed to reorder the YUV
parameters as they pass through the CDI. In addition, the CDI is able to detect the end of an
image and perform some truncation as well as overflow conditions. There is nothing
preventing the use of other data types such as JPEG or RGB (as long as the timing is followed),
but only YUV data can be sent to the display.
Camera images can also be sent to a DMA channel to store the image in external memory.
The I2C interface and GPIO are part of the interface to the camera module, but they are not
part of the CDI block. The I2C is used to set-up and control the camera module.
The camera module I2C lines must go high impedance when the supply is removed from the
camera. The I2C commands needed to control the camera, as well as the functional behavior
of the module, are also different for each implementation.
The ON-signal (GPIO) is used to power-on the camera from Standby or Off mode
(implementation dependent). This signal must be held low when the mobile equipment is
powered down and during the mobile equipment reset period. The GPIO pin can also be an
input or high impedance during mobile equipment reset and start. In this case, it must have
pull-down to ground.
The camera module reset signal is an output to the camera module.
LGE Internal Use Only - 46 - Copyright © 2009 LG Electronics. Inc. All right reserved.

Only for training and service purposes