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MT9V012 Datasheet(PDF) 6 Page - Micron Technology |
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MT9V012 Datasheet(HTML) 6 Page - Micron Technology |
6 / 53 page ![]() PDF: 814eb99f/Source: 8175e929 Micron Technology, Inc., reserves the right to change products or specifications without notice. MT9V012_2.fm - Rev. B 2/05 EN 6 ©2004 Micron Technology, Inc. All rights reserved. MT9V012 - 1/6-Inch VGA CMOS Digital Image Sensor Functional Overview Preliminary‡ Figure 1: Block Diagram Functional Overview The MT9V012 is a progressive-scan sensor that generates a stream of pixel data qualified by LINE_VALID and FRAME_VALID signals. It uses an input master clock of 27 MHz (nominal). The data rate (pixel clock) is one half of the master clock frequency, which means that one pixel is generated every two master clock cycles. Figure 1 shows the sen- sor block diagram. The core of the sensor is an active-pixel array. The timing and control circuitry sequences through the rows of the array, resetting and then reading each row in turn. In the time interval between resetting a row and reading that row, the pixels in that row integrate incident light. The exposure is controlled by varying the time interval between reset and readout. Once a row has been read, the data from the columns is sequenced through an analog signal chain (providing offset correction and gain), and then through an ADC. The output from the ADC is a 10-bit value for each pixel in the array. The ADC output passes through a digital processing signal chain (which provides further offset correction, applies digital gain, and may perform pixel defect correction). The pixel array contains optically active and light shielded (“black”) pixels. The black pixels are used to provide data for on-chip offset correction algorithms (“black level” control). The sensor contains a set of 16-bit control and status registers that can be used to con- trol many aspects of the sensor behavior. These registers can be accessed through a two- wire serial interface. In this document, registers are specified either by name (e.g., col- umn start) or by register address (e.g., Reg0x04). Fields within a register are specified by bit or by bit range (e.g., Reg0x20[0] or Reg0x0B[13:0]). Table 6, Register Description, on page 23, describes the control and status registers. The output from the sensor is a Bayer pattern: alternate rows are a sequence of either green/red pixels or blue/green pixels. The offset and gain stages of the analog signal chain provide per-color control of the pixel data. The MT9V012 supports two different functional modes of operation: • Default mode: the sensor generates a VGA-sized image by default, with 10 parallel data outputs per pixel, and separate LINE_VALID, FRAME_VALID, and PIXCLK out- puts. All timing control is performed on-chip. • Serial mode: the sensor generates a VGA-sized image by default. Pixel data, LINE_VALID, and FRAME_VALID are encoded into a single serial data stream that uses a two-signal low-voltage differential signalling (LVDS) interface. All timing con- trol is performed on-chip. Active-Pixel Sensor (APS) Array Serial I/O Data Out Sync Signals Timing and Control Control Register Analog Processing ADC |