FOCUS Enhancements FS453 - Manual (Page 7)

FS453/4 AND FS455/6 DATA SHEET: HARDWARE REFERENCE
JANUARY, 2005, VERSION 3.0 7 COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
FOCUS Enhancements Semiconductor
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