Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`
`
`FS453/4 and FS455/6
`PC-to-TV Video Scan
`Converter
`
`
`
`
`
`FS453/4 and FS455/6
`Data Sheet Guides
`
`
`To make specialized information easier to find, the FS453/4 and FS455/6 Data Sheet is
`organized into separate reference guides. Each guide addresses a different purpose or
`user.
`
`
`
` (cid:134)
`
`The FS453/4 and FS455/6 Product Brief provides general information for all
`users.
` The FS453/4 and FS455/6 Hardware Reference is for
`system designers. It provides information on developing
`FS453/4 and FS455/6 applications. (This section now includes
`PCB Layout Guide)
`
` (cid:59)
`
`
`
` (cid:134)
`
`The FS453/4 and FS455/6 Software/Firmware Reference is for programmers.
`It provides information on programming the FS453/4 and FS455/6.
`
`
`If you need additional reference guides, contact your Focus Enhancements
`representative.
`
`
`
`
`
`
`Throughout this document "FS453" is used as a general term to reference the FS453,
`FS454, FS455, and FS456. The FS453 and FS454 are the PQFP versions of the chip,
`and the FS455 and FS456 are the BGA versions of the chip. The FS454 and FS456
`support Macrovision anti-copy protection, while the FS453 and FS455 do not.
`
`JANUARY, 2005, VERSION 3.0
`
`1
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`TMMI EX. 1006
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`3.
`
`Table of Contents, Figures & Tables
`
`3
`Document Overview
`1.
`4
`Introduction
`1.1 General Description ..............................4
`1.2 How does it work?.................................4
`1.2.1 SDTV Output ...............................4
`1.2.2 HDTV Output...............................4
`1.2.3 VGA (RGB) Output......................4
`1.3 General Physical Requirements ...........4
`2. Architectural Overview
`5
`2.1 Inputs ....................................................5
`2.1.1
`Input to Output Conversion Matrix6
`2.2 Color Space Converter .........................6
`2.3 Patented 2D Scaler...............................6
`2.4 Patented 2D Flicker Filter .....................7
`2.5 FIFO 7
`2.6 Post (Horizontal Up) Scaler ..................7
`2.7 Encoder and Inverse Color Space........7
`2.8 Bi and Tri-Level Sync Insertion (HDTV)7
`2.9 Configurable 10 bit DACs .....................7
`2.10 Clock Management ...............................7
`2.11 Oscillators and PLL...............................7
`2.12 Serial Control Interface .........................8
`2.13 Sync Timing Generator .........................8
`2.14 Input Synchronization ...........................8
`9
`Technical Highlights
`3.1 Scaling ..................................................9
`3.1.1 Video Scaler Challenges.............9
`3.1.2 FS453 Solution............................9
`3.2 Flicker Reduction ................................10
`3.2.1 Flicker Filter Challenges............10
`3.2.2 FS453 Solution..........................10
`3.3 Video Encoding...................................11
`3.3.1 Encoding Challenges ................11
`3.3.2 FS453 Solution..........................11
`4. Scaling and Positioning Notes
`12
`4.1 Vertical Scaling ...................................12
`4.2 Horizontal Scaling ...............................13
`4.3 Vertical and Horizontal Position..........13
`5. Pin Assignments
`14
`5.1 FS453 ⇔ GCC Pin Mapping...............16
`5.2 Pin Descriptions ..................................17
`6. Control Register Function Map
`21
`6.1 Register Reference Table...................21
`7. Specifications
`24
`7.1 Absolute Maximum and Recommended
`Ratings ................................................24
`7.2 Electrical Characteristics.....................25
`7.3 Switching Characteristics....................27
`8. Mechanical Dimensions
`28
`8.1 80-Lead PQFP Package .....................28
`8.2 88-Lead FBGA Package .....................29
`9. Component Placement
`30
`9.1 Power/Ground.....................................30
`
`9.1.1 Power ........................................ 30
`9.1.2 Ground ...................................... 31
`9.2 DIGITAL SIGNALS ............................. 31
`9.2.1 Digital Signal Routing................ 31
`9.2.2 Video Inputs .............................. 32
`9.3 ANALOG SIGNALS ............................ 32
`9.3.1 Video Output Filters .................. 32
`9.4 CLOCK/OSCILLATOR........................ 34
`9.4.1 Reference Crystal Oscillator ..... 34
`9.4.2 FS453 Pixel Clock..................... 34
`9.4.3 Pixel Clock Mode ...................... 35
`9.5 EMI Case Study.................................. 37
`9.6 Solder Re-flow Profiles ....................... 38
`10. Revision History
`40
`11. Order Information
`41
`
`Figure 1: FS453 Functional Block Diagram..............5
`Figure 2: FS453 Scaler Luma Frequency
`Response .........................................................9
`Figure 3: FS453 Flicker Filter Diagonal
`Response .......................................................10
`Figure 4: Equations for VTOTAL and VSC.............12
`Figure 5: VTOTAL and VACTIVE ratios must
`match..............................................................12
`Figure 6: HSC Equations........................................13
`Figure 7: PQFP Pin Diagram..................................14
`Figure 8 FBGA Pin Diagram...................................15
`Figure 9: PQFP Package Outline & Dimensions....28
`Figure 10 FBGA Package Outline & Dimensions...29
`Figure 11: Recommended Power Filter
`Networks ........................................................31
`Figure 12: Recommended Output Filter .................33
`Figure 13: Pixel Clock Pseudo-master Mode .........36
`Figure 14: Pixel Clock Slave Mode.........................36
`Figure 15 PQFP Package (Lead Solder)................38
`Figure 16 FBGA Package (Lead Solder)................39
`Figure 17 PQFP or FBGA Package (Lead-Free
`Solder)............................................................39
`
`Table 1: Input to Output Conversion Matrix..............6
`Table 2: FS453 PQFP Pin Assignments ................14
`Table 3: FS453 to GCC Pin Mapping .....................16
`Table 4: FS453 Pin Descriptions ............................20
`Table 5: Register Reference Table.........................23
`Table 6: Absolute Maximum and Recommended
`Ratings ...........................................................24
`Table 7: Electrical Characteristics ..........................26
`Table 8: Switching Characteristics .........................27
`Table 9: Package Dimensions................................28
`Table 10: Output Filter Component Values ............34
`
`
`
`JANUARY, 2005, VERSION 3.0
`
`2
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`Document Overview
`The Hardware Reference provides information needed to integrate the FS453 Video Processor into
`system hardware. The reference is divided into eight sections:
`
`
`Introduction – explains the purpose and general flow of the FS453. Begins on page 4.
`
`1.
`
`2. Architectural Overview – defines the major sections of the FS453 and describes how they work
`together. Begins on page 5.
`
`3. Technical Highlights – explains technical challenges faced by scan converters, and explains
`how the FS453 accomplishes Scaling, Flicker Filtering, and Video Encoding. Begins on page 9.
`
`4. Scaling and Positioning Notes– provides more detailed information on how the FS453
`performs Scaling and Positioning. Begins on page 12.
`
`5. Pin Assignments – lists the pin names and maps their correspondence to sample host graphics
`controller chips. Describes pin functions. Begins on page 14.
`
`6. Control Register Function Map – lists the Control Register functions and register numbers. If
`you need more information about the Control Registers, please request a copy of the FS453/4
`and FS455/6 Software / Firmware Reference from your Focus Enhancements representative.
`The Control Register Function Map begins on page 21.
`
`
`7. Specifications – provides information on the Absolute Maximum and Recommended Ratings,
`the Electrical Characteristics, and the Switching Characteristics. Begins on page 24.
`
`8. Mechanical Dimensions – describes the FS453's 80-lead PQFP and 88-lead FBGA packages.
`Begins on page 28.
`
`9. Component Placement – gives guidelines for the placement and layout of components
`associated with the FS453. Begins on page 30.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`JANUARY, 2005, VERSION 3.0
`
`3
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`1. Introduction
`1.1 General Description
`The FS453 PC to TV Video Scan Converter provides broadcast-quality scan conversion for graphics
`cards, motherboard chip sets, video game consoles, consumer electronics and other PC-to-TV
`applications. Compatible with most graphics controller chips (GCC), the FS453 takes in high-resolution
`computer graphics input (VGA through SXGA) and produces SDTV (Standard Definition Television) or
`HDTV (High Definition Television) analog output. In SDTV mode the FS453 converts, scales, removes
`flicker, interlaces and encodes the data into NTSC or PAL formats. In HDTV mode, it performs color
`space conversions and then inserts the required syncs for output. The FS453's patented technology
`enables it to scale the converted image to fill the TV screen and display flicker-free graphics with sharply
`defined text.
`1.2 How does it work?
`The FS453 provides a glueless digital interface to most GCCs. It accepts computer-generated digital
`graphics input in RGB or YCrCb format. The FS453 receives initialization and basic configuration
`information through its I2C*-compatible SIO port with simple register Read/Write commands. How the
`FS453 actually processes and converts the graphics information depends on the kind of video output
`selected. (Refer to Figure 1: FS453 Functional Block Diagram on page 5.)
`
`1.2.1 SDTV Output
`For example, to create SDTV output the FS453 first changes RGB video to YCrCb. It uses patented
`technology to scale (in other words, to proportionately increase or decrease) the number of video lines
`and pixels per line to correspond to the specific SDTV standard. This allows the FS453 to precisely fill
`the user's television screen without adding artifacts such as blank areas, or distorting the graphics image.
`The FS453 uses more patented technology to adaptively remove the flicker effects common to SDTV
`while keeping fine detail (such as text) clear and sharp. The FS453 then encodes the processed image
`into broadcast quality, interlaced SDTV video and sends it out through the DACs. For European SCART
`output, the FS453 converts the image into RGB video and sends the R, G and B signals through separate
`DACs.
`
`1.2.2 HDTV Output
`To convert high-resolution computer graphics to high resolution HDTV output the FS453 converts the
`digital video (whether RGB or YCrCb format) to YPrPb (analog component video). It adds Bi- and Tri-
`Level Syncs as required by the selected standard and routes the analog HDTV video through the DACs.
`
`1.2.3 VGA (RGB) Output
`The FS453 can also provide VGA output. In this mode, it allows the GCC's RGB images to pass
`unchanged directly through to the DACs. The HSync and VSync signals must be driven by the GCC.
`1.3 General Physical Requirements
`Implementing the FS453 in your system will require very few components – just a 27 MHz clock and
`passive parts. The FS453 uses an 80-lead Quad Flat Pack (PQFP) or an 88-lead Fine-pitch Ball Grid
`Array (FBGA) package and requires power from +1.8V digital and +3.3V analog supplies.
`
`
`*Note: I2C is a registered trademark of Philips Corporation. The FS453 Serial I/O bus is similar but not identical to the Philips I2C
`bus.
`JANUARY, 2005, VERSION 3.0
`
`4
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`2. Architectural Overview
`The FS453 has the following major sections:
`Inputs P[23:0]
`•
`• Programmable Color Space Converter
`• Patented 2D (Horizontal and Vertical)
`Scaling
`• Patented 2D Flicker Filter
`• FIFO
`• Post (Horizontal Up) Scaler
`Inverse Color Space
`•
`
`
`
`
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`• Broadcast Quality Encoder
`• HDTV Bi- & Tri-Level Sync Insertion
`• Configurable 10 bit DACs
`• Clock Management
`• Oscillators and PLL
`• Serial Control Interface
`• Sync Timing Generator
`
`10-bit
`
`10-bit
`
`10-bit
`
`10-bit
`
`Multiplexer
`
`Inverse
`Color
`Space
`
`Encoder
`
`FIFO
`
`Post
`Scaler
`
`Multiplexer
`
`Bi & Tri-Level
`Sync
`Insertion
`
`2D
`Scaler
`
`2D
`Flicker
`Filter
`
`Color
`Space
`Conv.
`
`Demux
`
`P[23:0]
`
`Serial
`Control
`Interface
`
`SDATA
`
`SCLK
`
`ClkIn
`
`Clock Management
`
`to internal clocks
`
`Sync
`Timing
`Generator
`
`DAC A
`
`DAC B
`
`DAC C
`
`DAC D
`
`VSync
`HSync
`Blank
`Field
`
`ClkOut
`
`
`
`Crystal
`
`XTAL
`OSC
`
`NCO
`
`PLL
`
`Figure 1: FS453 Functional Block Diagram
`
`
`2.1 Inputs
`The FS453 accepts computer graphics images in many different resolutions and pixel frequencies on
`P[23:0]. The FS453 adaptively process this information for optimal display on SDTV and HDTV television
`sets.
`
`JANUARY, 2005, VERSION 3.0
`
`5
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`2.1.1 Input to Output Conversion Matrix
`Table 1 below lists some commonly used input modes and the correspondingly supported output modes.
`SDTV input dimensions are completely configurable, subject only to pixel clock range limitations.
`
`
`Input Configuration
`
`Pixels
`
`Lines
`
`640 - 720
`640 - 720
`800
`1024
`1280
`1920
`
`480
`576
`600
`768
`720
`1080
`
`SDTV
`NTSC
`@59.94Hz
`
`∗
`∗
`∗
`∗
`∗ (b)
`
`
`Output Configuration
`HDTV
`720p
`@60Hz
`
`
`
`
`∗(a)
`
`
`PAL
`@50Hz
`
`∗
`∗
`∗
`∗
`∗ (b)
`
`
`480p
`@60Hz
`∗(a)
`
`
`
`
`
`
`1080i
`@60Hz
`
`
`
`
`
`∗(c)
`
`Table 1: Input to Output Conversion Matrix
`
`Notes:
`(a) No scaling supported
`(b) Subject to the maximum 150 MHz pixel rate
`(c) No scaling or interlacing supported, input data must be interlaced
`
`2.2 Color Space Converter
`The programmable Color Space Converter receives either RGB or YCrCb data from the input port. If the
`data is RGB, it is converted to YCrCb using programmable coefficients. Each of the Y, Cr, and Cb
`components can then be independently scaled in amplitude with programmable multipliers. This
`programmability supports both SDTV and HDTV color space matrices.
`
`2.3 Patented 2D Scaler
`The Patented 2D Scaler receives data from the Color Space Converter. It performs vertical (up or down)
`scaling based on the value programmed in the VSC (Vertical Scaling Coefficient) register, offset 06h. It
`performs horizontal (down) scaling based on the downscale value programmed in the HSC (Horizontal
`Scaling Coefficient) register, offset 08h.
`
`Because different video standards call for different numbers of lines and different numbers of pixels per
`line, scan converters add or subtract lines and areas to fit graphics images onto different sizes of TV
`screens. Most scan converters use simple line-dropping algorithms and fixed aspect ratios.
`Unfortunately, these techniques can introduce shape-distorting artifacts and surround the actual image
`with blank areas.
`
`The FS453, however, uses patented technology that can scale the graphics image without creating
`artifacts. The patented 2D Scaler can independently upscale or downscale an image in both the
`horizontal (pixels) and vertical (lines) directions. Its scaling functions provide equal weight to all pixels
`and lines in the source material for all scaling factors. This allows users to perfectly fit the graphics image
`to their TV screens without adding scaling artifacts or large blank borders.
`
`
`JANUARY, 2005, VERSION 3.0
`
`6
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`FS453/4 AND FS455/6
`2.4 Patented 2D Flicker Filter
`The Patented 2D Flicker Filter receives video lines from the 2D Scaler and performs vertical filtering to
`reduce or eliminate perceived flicker that is an artifact of the interlaced television format.
`
`The FS453's flicker filter is significantly more effective than a typical three-line-average flicker filter. The
`FS453’s flicker filter consists of joint horizontal (Sharpness) and vertical (Flicker) controls. Three-line-
`average flicker filters do reduce the visual effect of interlaced image flicker, but they also introduce
`blurring. The flicker dimension of the FS453's filter reduces image flicker, while the sharpness dimension
`of the FS453's filter reduces image blurring. Both the sharpness and flicker registers can be programmed
`over a wide range of values to allow the user to customer tailor the filter settings to different display
`devices.
`2.5 FIFO
`The Flicker Filter stores video data in a FIFO memory. This memory allows the video data to be
`transferred from the graphics clock domain to the TV clock domain.
`2.6 Post (Horizontal Up) Scaler
`The Post Scaler draws information from the FIFO as necessary and scales it horizontally based on the
`up-scale value programmed in the Horizontal Scaling Coefficient (HSC) register. The scaled data is
`provided at the television clock rate to the SDTV video encoder and the Inverse Color Space.
`2.7 Encoder and Inverse Color Space
`The FS453 contains a broadcast quality, 2X oversampled video encoder with an Inverse Color Space
`matrix. The encoder combines the chrominance, luminance, and timing information into broadcast quality
`NTSC or PAL composite and YC (S-Video) signals and sends them to the DACs.
`
`The Inverse Color Space transforms YCrCb video data to the RGB color space required for SCART
`output. If the Inverse Color Space is not used, then the Encoder converts YCrCb to YPrPb as required
`for SDTV YPrPb output. The RGB or YPrPb signals are sent to the DACs synchronized with the
`Encoder's composite signal.
`
`The FS454 and FS456, which are otherwise identical to the FS453 and FS455, respectively, incorporate
`Macrovision 7 anti-copy protection in the encoder. The FS454 and FS456 also include 480p protection.
`2.8 Bi and Tri-Level Sync Insertion (HDTV)
`The FS453 also offers HDTV Syncs output modes. The color matrix, output level, and sync type are fully
`programmable allowing for compatibility with the multiple HDTV standards. The FS453 inserts bi-level or
`tri-level sync signals as defined by the standards.
`2.9 Configurable 10 bit DACs
`The four output DACs (Digital/Analog Converters) can be configured for several output formats: RGB
`component output (VGA); RGB with CVBS (SCART); CVBS (2 optional) and Y/C (S-Video); and YPrPb
`component output (HDTV or SDTV). To conserve power the DACs can be run in low power mode or can
`be completely powered down when not in use.
`2.10 Clock Management
`The FS453 synthesizes a 0.78125-150 MHz clock from the 27 MHz XTAL_IN and supplies this clock
`(CLKOUT) to the GCC. The clock is buffered and returned to the FS453 (CLKIN_P) synchronous to the
`pixel data and sync information. This clock has a 1.5 Hz resolution and can be adjusted so that the GCC
`scaled input data rate exactly matches the ITU-R BT.656 output data rate.
`2.11 Oscillators and PLL
`The FS453 clock generation circuit operates in one of two modes, NCO (Numerically Controlled
`Oscillator) mode or PLL (Phase Locked Loop) mode. In NCO mode, the numerically controlled oscillator
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`JANUARY, 2005, VERSION 3.0
`7
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`is used to achieve the finest clock resolution, using a dithered clock. In PLL mode, the NCO is bypassed
`and the clock is not dithered. The NCO can be used when HTOTAL and VTOTAL values have additional
`constraints that prevent selection of values that are factors of the TV pixel rate.
`2.12 Serial Control Interface
`The FS453 registers are accessed through a serial input/output bus (SIO) which is I2C*-compatible and
`SMBus-compatible. These registers can be read or written at any time the part is receiving a reference
`clock at XTAL_IN and not being held in reset via the RESET_L pin.
`2.13 Sync Timing Generator
`The Sync Timing Generator provides/accepts HSync, VSync, Field and Blank signals to/from the graphics
`controller.
`2.14 Input Synchronization
`The FS453 can operate in pseudo-master mode or slave mode. In pseudo-master mode, the GCC
`derives the VGA pixel clock, horizontal sync, and vertical sync from CLKOUT supplied by the FS453. In
`slave mode, the GCC generates the pixel clock, syncs and data, and the FS453 must be programmed to
`generate the same pixel clock, using a common reference. Use the slave mode when the GCC does not
`have a pixel clock input.
`
`
`
`*Note: I2C is a registered trademark of Philips Corporation. The FS453 Serial I/O bus is similar but not identical to the Philips I2C
`bus.
`JANUARY, 2005, VERSION 3.0
`
`8
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`3. Technical Highlights
`Creating clear, broadcast quality television video from high resolution computer graphics is a complex
`process. PC-to-TV Video Scan Converters have to surmount many technical obstacles. The most
`challenging of these are scaling, flicker reduction, and encoding.
`3.1 Scaling
`Converting high-resolution computer images into relatively low-resolution TV images (such as converting
`VGA or XGA images into NTSC standard definition television) is an inherently lossy process that requires
`a video scaler. For example, converting an image with 1000 pixels in a line into an image with only 500
`pixels in a line, means that there must be 50% less data in each line of output. The video scaler has to
`perform its tasks effectively without further degrading the image.
`
`3.1.1 Video Scaler Challenges
`Therefore, in addition to reducing pixel count and interpolating pixel values, the scaler must not alter the
`digital video data by adding artifacts. Examples of artifacts are the introduction of repeated pixels; the
`complete loss of pixel data; and the creation of new pixel colors that are not interpolations of original pixel
`colors.
`In effect, the video scaler should behave like a high quality filter. It should have a gradual frequency roll
`off with a good step response and little overshoot or ringing (less than 5%). This is ideal for maintaining
`video quality with detailed images (such as text). Detailed images produce rapid output step transitions
`that need to be executed cleanly.
`
`3.1.2 FS453 Solution
`The following diagram (Figure 2) illustrates the response of the FS453's video scaler. It is a normalized
`plot of the Luma frequency response of the FS453's video scaler. As we can see, the FS453's patented
`video scaler behaves like a high quality filter with only a gradual frequency roll off.
`
`
`0.6
`0.5
`0.4
`Normalized Frequency
`
`0.7
`
`0.8
`
`0.9
`
`1
`
`0.1
`
`0.2
`
`0.3
`
`05
`
`5
`
`10
`
`15
`
`20
`
`25
`
`0
`
`Gain in Decibels
`
`Scale 7/8
`Scale 3/4
`Scale 5/8
`Scale 1/2
`Figure 2: FS453 Scaler Luma Frequency Response
`
`
`
`
`
`JANUARY, 2005, VERSION 3.0
`
`9
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`FS453/4 AND FS455/6
`3.2 Flicker Reduction
`Computer images are displayed progressively. That is, for a given frame of video, each line of video is
`scanned onto the monitor sequentially. SDTV images, however, are interlaced. Each SDTV frame of
`video is broken into two fields (one composed of odd lines and the other of even lines). First the odd
`lines are scanned onto the TV, and then the even lines are scanned onto the TV.
`
`The energy decay rate of the phosphors on a TV screen is fast enough that the older field of video will
`appear somewhat dimmer than the newer field of video. As the fields are constantly changing, this can
`result in a visible flicker between the two fields of data on the TV screen. This flicker is especially visible
`when one field contains a long dark line, while an adjacent line (in the other field) contains a long white
`line. The higher energy line will decay in brightness much faster than the low energy line, and in turn will
`appear to flicker heavily.
`
`Most scan converters simply average the pixel data between lines. This removes the Black-or-White
`relationships between lines that viewers recognize as video flicker. The problem with this solution is that
`data becomes blurred. Single black or white lines are reduced to grays. Detailed areas of video (such as
`the gap in the letter ‘e’) lose their distinction.
`
`
`3.2.1 Flicker Filter Challenges
`The goal is to completely remove flicker from the image without blurring detailed video. To preserve the
`video details, the flicker filter should have a flat frequency response (+/- 1dB) between pixels in the
`horizontal, and diagonal directions. It must also avoid introducing new artifacts into the digital video
`stream. Artifacts include repeating pixels, losing pixels; and creating colors that are not interpolations of
`original pixel colors.
`
`3.2.2 FS453 Solution
`The FS453 uses a patented flicker filter that calculates output pixel values as a function of both vertical
`(line averaging) and horizontal (pixel averaging) pixel relationships. In effect the FS453 can decide
`where and how to reduce flicker within the image.
`
`Figure 3 (below) shows a normalized plot of the frequency response of pixels along diagonal after being
`processed by the FS453's flicker filter. The response is flat for the majority of the frequency space. This
`maintains pixel sharpness while providing excellent flicker suppression.
`
`0.6
`0.5
`0.4
`Normalized Frequency
`
`0.7
`
`0.8
`
`0.9
`
`1
`
`1
`
`0.75
`
`0.5
`
`0.25
`
`0
`
`0.25
`
`0.5
`
`0.75
`
`Gain in Decibels
`
`1
`
`0
`
`0.1
`
`0.2
`
`0.3
`
`Horizontal Direction
`Diagonal at 27 degrees
`Diagonal at 45 degrees
`Figure 3: FS453 Flicker Filter Diagonal Response
`
`
`
`JANUARY, 2005, VERSION 3.0
`
`10
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`
`
`FS453/4 AND FS455/6
`3.3 Video Encoding
`Unlike component video formats (PC and HDTV) that process the color information separately to avoid
`interference, broadcast SDTV combines all picture information into a single, composite signal. SDTV
`standards have been strictly defined to protect video quality and to allow television manufacturers to
`design and build large volumes of systems with confidence that their signal decoders will work—
`regardless of variances in final product tolerances.
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`3.3.1 Encoding Challenges
`If a video encoder does not adhere closely to these standards, it may produce video artifacts on many
`consumer televisions. Unfortunately, most scan converters use signal encoders that don't strictly follow
`NTSC and PAL guidelines. Their encoders can increase artifacts such as chroma crawl and color
`bleeding/smearing.
`
`To meet broadcast quality a video encoder must comply with the NTSC (EIA-170A, SMPTE-170M) and
`PAL (ITU-R624-3) standards in all modes. Of key importance are the specifications related to accurate
`timing and signal amplitudes, video subcarrier frequency good to +/- 5Hz, and horizontal lock with zero
`SC-H phase. The encoder must use a low jitter crystal (50 ppm) to drive DAC output directly. The DACs
`should have 10 bits of resolution, and exhibit good differential gain and differential phase characteristics.
`The video encoder must be able to pre-filter composite video (CVBS) to prevent luma(Y)/chroma(C) cross
`talk.
`
`3.3.2 FS453 Solution
`The FS453 features a broadcast quality encoder. It uses tunable Y-notch and C-bandpass filters to
`prevent the creation of video artifacts and to meet all specifications. The FS453's encoder subcarrier is
`programmable in frequency and phase. Because of the encoder's independence of color format, vertical
`sync, and number of lines, the FS453 is able to support many SDTV video standards, including all of the
`South American variations. The FS453 can output NTSC M, J and PAL B, D, G, H, I, M, N, Combination
`N, and PAL-60 formats with 10 bits of resolution. Both Composite and S-Video outputs are available
`simultaneously. In addition to encoded PAL or NTSC, the user may select analog SCART RGB outputs.
`Each channel of RGB has 10 bits of resolution. Note that the 10-bit DACs exceed the bit depth supported
`by the 8-bits available at the FS453 input.
`
`JANUARY, 2005, VERSION 3.0
`
`11
`
`COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
`FOCUS Enhancements Semiconductor
`
`
`

`

`Downloaded from www.Manualslib.com manuals search engine
`
`FS453/4 AND FS455/6
`
`
`
`DATA SHEET: HARDWARE REFERENCE
`
`4. Scaling and Positioning Notes
`The FS453 graphics converter does not use a frame memory. Therefore, the FS453 input video frame
`rate must be synchronous to and match the output video field or frame rate. In SDTV modes, the FS453
`uses internal line memories in order to perform horizontal and vertical scaling. This imposes certain
`requirements on the scale and position settings.
`4.1 Vertical Scaling
`Because the frame/field rates are synchronous, and no frame memory is available, the ratios of input to
`output VTOTAL and input to output VACTIVE must match. (See Figure 4 below.) In this sense, the
`output VACTIVE is not necessarily the total active lines of the selected TV standard, but is the number of
`TV lines that will contain active video information from the input source material. If the output VACTIVE
`value is smaller than the value specified by the TV standard, then the FS453 will place borders and below
`the image. TV_VTOTAL and GCC_VACTIVE in the VTOTAL equation are determined by the selected
`TV standard and graphics mode. TV_VACTIVE is selected to set the desired number of TV lines
`containing video information. The Vertical Scaling Coefficient is programmed in register 06h. The ratio of
`input to output VTOTAL also determines the vertical scaling factor used. Note that calculations are done
`using the output frame size, even though the output is interlaced, because interlacing is done after
`vertical scaling.
`
`
`
`
`
`
`
`
` G C C _V A C T IV E / G C C _ V T O T A L = T V _V A C T IV E /T V _V T O T A L
`
` Fo r dow n scaling, V S C = (T V _ V T O T A L / G C C _ V T O T A L ) * 65,5 36
` Fo r upscaling, V SC = (T V _V T O T A L / G C C _V T O T A L – 1 ) * 6 5,53 6
`
`
`
`Figure 4: Equations for VTOTAL and VSC
`
`
`
`The number of active lines of computer graphics in a frame.
`The total number of lines in a computer graphics frame, including active and blanking.
`The number of lines in a TV video frame that will contain scaled graphics data.
`The total number of lines in a TV video frame. PAL has 625 lines. NTSC has 525 lines.
`
`
`Notes:
`GCC_VACTIVE:
`GCC_VTOTAL:
`
`TV_VACTIVE:
`
`TV_VTOTAL:
`
`
`For example, consider a case where the input graphics active area contains 600 lines and the selected
`TV standard is NTSC. In NTSC, TV_VTOTAL is 525 lines per frame and the full-size active area is 487
`lines per frame. To program the FS453 to scale the GRAPHICS image to fit on 400 lines of TV video (for
`example, to fit the image within the TV bezel), set TV_VACTIVE to 400. This sets three of the four
`parameters in the equation, and solving for VGA_VTOTAL results in a value of 787.5. Because values
`must be integers, set VGA_VTOTAL to 788. The scaled image will still occupy approximately 400 lines.
`Given these VTOTAL values, the vertical scaling factor is 0.6662, and the VSC register will be set to
`43,663 (0xAA8F).
`
`
`VGA_VACTIVE
`
`TV_VACTIVE
`
`VGA_VTOTAL
`
`TV_VTOTA