TLC34077 Datasheet, PDF (7/41 Pages) Texas Instruments – Video Interface Palette Data Manual

1 Introduction
The TLC34077 Video Interface Palette (VIP) is designed to provide lower system cost with a higher level
of integration by incorporating all the high-speed timing, synchronizing, and multiplexing logic usually
associated with graphics systems into one device, thus greatly reducing chip count. Since all high-speed
signals (excluding the clock source) are contained on-chip, RF noise considerations are simplified.
Maximum flexibility is provided through the pixel multiplexing scheme, which allows for 32-, 16-, and 8-bit
pixel buses to be accommodated without any circuit modification. The TLC34077 is software compatible
with the IMSG176/8 and Brooktree BT476/8 color palettes.
The TLC34077 VIP is pin-for-pin compatible with the TLC34076 VIP, but with a reduced feature set
optimized for cost sensitive, high-performance PC graphics applications. The TLC34077 is compatible with
a variety of graphics processors, including the ATI 68800 mach 32 series of graphics accelerators.
The TLC34077 features a separate VGA bus that allows data from the feature connector of most
VGA-supported personal computers to be fed directly into the palette without the need for external data
multiplexing. This allows a replacement graphics board to remain downward compatible by utilizing the
existing graphics circuitry often located on the motherboard.
The 24- and 16-bit true-color modes that are provided allow bits of color information to be transferred directly
from the pixel port to the DACs.
The TLC34077 has a 256-by-24 color lookup table with triple 8-bit video D/A converters capable of directly
driving a doubly terminated 75-Ω line. Sync generation is incorporated on the green output channel.
Clocking is provided through one of two TTL-compatible inputs and is software selectable. The video clock
output provides a software-selected divide ratio of the chosen clock input.
1.1 Features
• Versatile multiplexing interface allows lower pixel bus rate
• High level of integration to provide lower system cost and complexity
• Direct VGA pass-through capability
• True-color (direct-addressing) modes support various 24- and 16-bit formats
• 5-6-5 XGA format compatible
• 5-5-5 TARGA format compatible
• Directly interfaces to most graphics processors
• Triple 8-bit D/A converters
• 110- and 135-MHz versions
• 256-word color palette RAM
• On-chip voltage reference
• RS-343A-compatible outputs
• TTL-compatible inputs
• Standard MPU interface
• Pixel word mask
• On-chip clock selection
• Software downward compatible with INMOS IMSG176/8 and Brooktree BT476/8 color palettes
• TIGA™-software-standard compatible
• LinEPIC™ 1-µm CMOS process
LinEPIC and TIGA are trademarks of Texas Instruments Incorporated.
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