STPC STMicroelectronics, STPC Datasheet - Page 7

• Manufacturer Part Number: STPC
• Description: PC Compatible Embeded Microprocessor
• Manufacturer: STMicroelectronics

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The video output pipeline incorporates a video-
scaler and color space converter function and pro-
visions in the CRT controller to display a video
window. While repainting the screen the CRT con-
troller fetches both the video as well as the normal
non-video frame buffer in two separate internal
FIFOs (256-Bytes each). The video stream can be
color-space converted (optionally) and smooth
scaled. Smooth interpolative scaling in both hori-
zontal and vertical directions are implemented.
Color and Chroma key functions are also imple-
mented to allow mixing video stream with non-vid-
eo frame buffer.
The video output passes directly to the RAMDAC
for monitor output or through another optional
color space converter (RGB to 4:2:2 YCrCb) to the
programmable anti-flicker filter. The flicker filter is
configured as either a two line filter with gamma
correction (primarily designed for DOS type text)
or a 3 line flicker filter (primarily designed for Win-
dows type displays). The flicker filter is optional
and can be software disabled for use with video on
large screen areas.
The Video output pipeline of the STPC Consumer
interfaces directly to the internal digital TV encod-
er. It takes a 24 bit RGB non-interlaced pixel
stream and converts to a multiplexed 4:2:2 YCrCb
8 bit output stream, the logic includes a progres-
sive to interlaced scan converter and logic to in-
sert appropriate CCIR656 timing reference codes
into the output stream. It facilitates the high quality
display of VGA or full screen video streams re-
ceived via the Video input port to standard NTSC
or PAL televisions.
The STPC Consumer core is compliant with the
Advanced Power Management (APM) specifica-
tion to provide a standard method by which the
BIOS can control the power used by personal
computers. The Power Management Unit module
(PMU) controls the power consumption by provid-
ing a comprehensive set of features that control
the power usage and supports compliance with
the United States Environmental Protection Agen-
cy’s Energy Star Computer Program. The PMU
provides following hardware structures to assist
the software in managing the power consumption
by the system.
- System Activity Detection.
- 3 power-down timers detecting system inactivity:
- House-keeping activity detection.
- Doze timer (short durations).
- Stand-by timer (medium durations).
- Suspend timer (long durations).
Issue 1.2
- House-keeping timer to cope with short bursts of
house-keeping activity while dozing or in stand-by
state.
- Peripheral activity detection.
- Peripheral timer detecting peripheral inactivity
- SUSP# modulation to adjust the system perform-
ance in various power down states of the system
including full power on state.
- Power control outputs to disable power from dif-
ferent planes of the board.
Lack of system activity for progressively longer
period of times is detected by the three power
down timers. These timers can generate SMI in-
terrupts to CPU so that the SMM software can put
the system in decreasing states of power con-
sumption. Alternatively, system activity in a power
down state can generate SMI interrupt to allow the
software to bring the system back up to full power
on state. The chip-set supports up to three power
down states: Doze state, Stand-by state and Sus-
pend mode. These correspond to decreasing lev-
els of power savings.
Power down puts the STPC Consumer into sus-
pend mode. The processor completes execution
of the current instruction, any pending decoded in-
structions and associated bus cycles. During the
suspend mode, internal clocks are stopped. Re-
moving power down, the processor resumes in-
struction fetching and begins execution in the in-
struction stream at the point it had stopped.
A reference design for the STPC Consumer is
available including the schematics and layout
files, the design is a PC ATX motherboard design.
The design is available as a demonstration board
for application and system development.
The STPC Consumer is supported by several
BIOS vendors, including the super I/O device
used in the reference design. Drivers for 2D accel-
erator, video features and EIDE are availaible on
various operating systems.
The STPC Consumer has been designed using
modern reusable modular design techniques, it is
possible to add or remove the standard features of
the STPC Consumer or other variants of the
5ST86 family. Contact your local STMicroelecton-
ics sales office for further information.
GENERAL DESCRIPTION
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