- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385879 > STV0676 (意法半導(dǎo)體) CMOS Digital Camera Co-processor PDF資料下載
參數(shù)資料
| 型號： | STV0676 |
| 廠商： | 意法半導(dǎo)體 |
| 英文描述： | CMOS Digital Camera Co-processor |
| 中文描述： | CMOS數(shù)字相機(jī)協(xié)處理器 |
| 文件頁數(shù)： | 7/21頁 |
| 文件大小： | 153K |
| 代理商： | STV0676 |
7/21
STV0676
Overview
1.3
Auto exposure and gain control
The STV0676 automatically controls the sensor exposure, which is evaluated (and, where
necessary modified) once per frame, where a frame consists of 2 video fields. The video fields are
identical in length, that is, they do not contain any of the half line detail of the analogue video
standards like CCIR or NTSC. Two fields per frame are required by the internal sensor video timing
model. Integration time, sensor analogue gain and STV0676 digital gain are all used to control the
overall exposure. The STV0676 exposure algorithm uses an asymptotic approach in calculating the
change required in the present exposure value to approach the requested exposure target.
1.4
Defect correction
STV0676 automatically detects and corrects pixel defects without the need for any additional
components or sensor calibration procedures. This greatly simplifies camera assembly and test
when compared with previous EEPROM-based defect correction schemes. The pixel defect
correction scheme ensures that the STV0676 + ST CMOS sensor appears as a ‘defect free’
chipset.
1.5
Video compression (VC) engine
The video compression engine performs 3 main functions:
G
up scaling of input YCbCr 4:2:2 video stream from the VP (typically to scale from QVGA to CIF
image formats),
G
compression and encoding of YCbCr stream into Motion-JPEG (M-JPEG) format,
G
USB bandwidth monitoring.
The data stream from the VP can be up to VGA size. The scaler in VC can downsize this image.
Once scaled the video stream is then converted into M-JPEG format. M-JPEG simply treats video
as a series of JPEG still images. The conversion is realised via a sequential DCT (discrete cosine
transform) with Huffman encoding. After transfer over USB, the M-JPEG stream is decoded in the
device driver running on the host.
The VC module is capable of compression ratios of up to 100:1 although this is scene-dependent.
Image framerate produced by the STV0676 chipset is fixed and furthermore the available USB
bandwidth is also fixed (within the software driver). The VC module varies the compression ratio to
match the fluctuating input video data rates to the available USB bandwidth and required framerate.
The final stage of the VC block manages the data transfer from the local VC FIFO store to the USB
core. STV0676 performs this management automatically by employing long-term (frame-level) and
short-term (block-level) compression management.
1.6
Control processor
The embedded 8052 microprocessor core controls the data flow through the major sub blocks
within STV0676 as well as the I
2
C communications to reconfigure the VP corresponding to requests
from the device driver.
1.7
Power management
The chipset conforms to all power requirements specified by USB Version 1.1.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| STV0684 | Digital Camera Processor |
| STV10NA40 | N-CHANNEL ENHANCEMEMT MODE FAST POWER MOS TRANSISTOR |
| STV1601A | SERIAL INTERFACE TRANSMISSION ENCODER |
| STV60NE06-16 | N - CHANNEL 60V - 0.013ohm - 60A PowerSO-10 STripFET POWER MOSFET |
| STV6400 | DOUBLE SCART INTERFACE |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| STV0680 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:DUAL-MODE DIGITAL CAMERA CHIPSET |
| STV0680-001 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Low Cost Digital Camera (LCDC) Chipset |
| STV0680A-002 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Low Cost Digital Camera (LCDC) Chipset |
| STV0680B | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:DUAL-MODE DIGITAL CAMERA CHIPSET |
| STV0680B-001 | 制造商:STMicroelectronics 功能描述:DUAL-MODE DIGITAL CAMERA CHIPSET - Bulk |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。