Electronic Design

Display Controller Complies With The DVI Specification

The CH7009 Digital Video Interface (DVI) display controller serves as an interface between a digital graphics controller and either a transition-minimized differential-signaling (TMDS) link output or a TV. According to its manufacturer, it's the first controller containing the interfaces for both outputs in a single IC package.

The device processes the digital graphics that arrive at the data entry port, which is 12 bits wide. It then feeds the processed data to either a TMDS link or a TV output. The TMDS link complies with the DVI 1.0 specification, enabling the CH7009 to drive a DVI display at a pixel rate of up to 165 MHz.

Since the two outputs run at different clock frequencies, the device may be programmed to feed either the TMDS output or the TV output. NTSC, PAL, and SCART formats are supported. When operating in the TMDS mode, the RGB output also can be applied via a DVI-I or a conventional VGA connection. This simultaneously takes the same data that's being delivered at the TMDS output and delivers it to a monitor. In the TV-OUT mode, the CH7009 performs noninterlaced to interlaced conversion with scaling and encoded data that complies with NTSC or PAL video standards. Composite video, s-video, and RGB output formats also are supported.

The CH7009 includes hot plug-in detection and an improved flicker filter. By increasing the number of taps on the filter, Chrontel has further reduced flicker—compared to the earlier CH7007, which only had the TV-OUT function. Macrovision copy protection, also included, can be selected via programming. Macrovision prevents VCRs from copying analog TV outputs. This feature, however, doesn't interfere with TVs displaying the information. Furthermore, TV scaling support is increased to 1024 by 768 pixels.

Chrontel has released two other controllers, too. The CH7301 is a TMDS-only device, while the CH7011 is an encoder-only model. Both use the same technology contained in the CH7009. The devices are shipped in 64-pin LQFP packages. DVI content protection will be added to the TMDS port in July.

In 100-piece quantities, the CH7009 costs $7.00, the CH7301 is $4.80, and the CH7011 goes for $4.45.

Chrontel Inc., 2210 O'Toole Ave., San Jose, CA 95131; (408) 383-9328; fax (408) 383-9338; www.Chrontel.com.

TAGS: Components
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