DSP 104-plus, Reference Manual

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CS5530A for formatting and dispatch to the CRT or flat panel. The CS5530A
contains the RAMDAC for the analog CRT displays. In order to minimise the amount
of memory bandwidth taken up by the refreshing of the displays, the Geode GX1
incorporates data compression circuitry. Thus in normal operation only the
compressed representation of the graphics image needs to be read from the
SDRAM.
As well as offering VGA compatible logic for creation of images, the Geode GX1 also
incorporates a high-performance BITBLT graphics engine, driven by operating
system-specific drivers. This 2D graphics accelerator results in very high speed
updating of the display. Support for video playback is also provided – see section
3.11.
3.10.2 Using CRTs and TFT LCDs
The display controller drives CRTs, and can drive TFT LCD panels as well.
Simultaneous operation is possible.
By default the TP400 is configured for CRT operation only. Users can use the BIOS
Setup program to optionally enable TFT operation as well. This also allows the
display size to be set at 640 x 480, 800 x 600 or 1024 x 768. Use the Advanced /
Advanced Chipset Control / Geode GX1 LCD menu item. There are two clock
frequency options for the 1024 x 768 display. Choose the option that gives you the
most stable picture.
Connection to a CRT from the TP400 is made via the 16-way connector J6.
Connection to flat panel displays is made through the 40-way 0.05” pitch connector
J8. Connection is made from the J8 connector to flat panels using a ribbon cable.
Possible display resolutions for TFT displays are given in Table 5. Possible
resolutions for CRT displays are given in Table 6. Simultaneous CRT and flat panel
display is supported for resolutions of 640 x 480, 800 x 600 and 1024 x 768. (Some
of the higher colour depths and display sizes require the display resolution to be set
to “Super” in the BIOS Setup program).
RESOLUTION SIMULTANEOUS
COLOURS REFRESH
RATE DOTCLK RATE
8 BPP. 256 colours out of a
palette of 256. 60Hz 25.175MHz 640 X 480
16 BPP. 64k colours 5-6-5. 60Hz 25.175MHz
8 BPP. 256 colours out of a
palette of 256. 60Hz 40.0MHz 800 x 600
16 BPP. 64k colours 5-6-5. 60Hz 40.0MHz
8 BPP. 256 colours out of a
palette of 256. 50Hz or 60Hz 54MHz or 65MHz 1024 x 768
16 BPP. 64k colours 5-6-5. 50Hz or 60Hz 54MHz or 65MHz
TABLE 5 - TFT PANEL DISPLAY RESOLUTIONS