STM7710

Architecture

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The same video appears on both displays but each can be set up to format the video

differently and display with different timing. Separate video timing generators (VTGs) are

provided to support this.

The display processors are used to present the video from the display buffers and adapt the

decoded video format to a format suitable for display taking into account differences in

scanning method, resolution, aspect ratio and scanning frequency.

The main-display processor receives decoded or acquired video from memory and performs

block-to-line conversion, pan and scan, and vertical and horizontal format conversion. There

is also a linear median upconverter (LMU) to perform interlace-to-progressive conversion on

standard definition pictures using motion estimation.

The auxiliary-display processor receives decoded or acquired (and possibly decimated)

video and performs pan and scan, vertical format conversion, horizontal format conversion.

The output line size is limited to 720 pixels on the auxiliary-display processor and is

intended to output video for VCR recording.

2.9

Graphics display

2.9.1

Graphics layers

The STM7710 has two independent and identical graphics layers known as generic display

pipelines (GDPs) (see Figure 5). Each GDP receives pixel data from memory and features

the following.

●

Link-list-based display engine, for multiple viewport capabilities.

●

Support for ARGBargb formats, including:

–

ARGB1555,

–

ARGB4444,

–

RGB565,

–

RGB888,

–

ARGB8565,

–

ARGB8888.

●

Support for YCbCr4:2:2R, YCbCr888 formats.

●

Support for premultiplied or non-premultiplied RGB components.

●

Color space conversion matrix, (YCbCr 601/709, chroma signed/unsigned to RGB).

●

Gain and offset adjustment.

●

Per-pixel alpha channel combined with per-viewport global alpha.

●

5-tap horizontal sample rate converter for horizontal upscaling only, not downscaling.

Vertical resize is not possible. The horizontal sample rate converter can be used to

adapt the pixel aspect ratio. The resolution is 1/8th pixel (polyphase filter with eight

subpositions).

●

Color keying capability.