Display Drivers
- Albinleo Velappan (Deactivated)
This describes the display-driver of the XScale-based Trizeps-modules. The parameters for the display are read in this order ( parameters read later overwrite earlier values):
BootBitmap
[HKEY_LOCAL_MACHINE\Drivers\Display\Default]
If a BootBitmap has not been loaded, [HKEY_LOCAL_MACHINE\Drivers\Display\Default\
displayname]; wheredisplaynameis defined with [HKEY_LOCAL_MACHINE\Drivers\Display\Default] Name.
The registry-settings are found in the display.reg.
Registry-Key may vary depending on Trizeps-module and OS-version!
Registry Keys
Common to all Trizeps-Modules
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|---|---|---|
Key | Type | Description |
Name | STRING | Key holding the actual booted display (not the one to be booted!). |
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|---|---|---|
| ||
Key | Type | Description |
Name | STRING | Defines the name of the display, which parameters are to be used (Only in \Default). |
DisableBootPars | DWORD | If set to 1, ignore the BitmapBoot-parameters. |
CxScreen | DWORD | Horizontal-resolution. |
CyScreen | DWORD | Vertical-resolution. |
Feature | DWORD | Feature-Parameters; i.e. which GPIO to use as PWM, see: BitmapBoot Tool ( Trizeps II - V) |
DisplayOn | DWORD | GPIO which turns the display on/off. |
DisplayOnPol | DWORD | Polarity of DisplayOn-GPIO. |
BufferStrength | DWORD | BufferStrength of the display-lines (PXA270: 0..15; PXA320: 1..7; PXA168:0..3). |
Angle | DWORD | Angle ( 0, 90, 180, 270) with which the display starts. |
Angle2 | DWORD | Alternative Angle (0, 90, 180, 270) used by RotateScreen-applet. |
Trizeps 2,3,4 and 5
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|---|---|---|
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Key | Type | Description |
Name | STRING | Defines the name of the display, which parameters are to be used (Only in \Default). |
Bpp | DWORD | Color-depth ( 4, 8, 16). |
Control0 - Control3 | DWORD | Contain display parameters. See Intel/Marvell PXAxxx Developers Manual. |
EraseFrameBufferOnStart | DWORD | If set to 1, clear the framebuffer on start (black screen). |
SuspendColor | DWORD | Clear the framebuffer with this color, before going into suspend. |
UseInternalSRAM | DWORD | If set to 1 uses internal SRAM for framebuffer. If framebuffer is to big, this could split the framebuffer (internal SRAM and SDRAM). This might be a problem for application that directly access the framebuffer, i.e. DirectDraw. |
DisableOutput | DWORD | Disables output of display signals. |
Trizeps 6
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|---|---|---|
| ||
Key | Type | Description |
Bpp | DWORD | Valid values: 12,16,18,24.
Selects number of display-lines to use. |
BaseFramePixelFormat | DWORD | Selects Pixel-Format used for framebuffer:
4: RGB565 (16Bpp)
8: RGB8880 (24Bpp) |
ClockDivider | DWORD | See Marvell PXA168 Developers Manual.
Typical this is set to (0x80000000 | divider);
where divider = 312MHz / PCLK-frequency. |
HBackPorch | DWORD | Horizontal Back-Porch in Pixel-Clks |
HFrontPorch | DWORD | Horizontal Front-Porch in Pixel-Clks |
HSyncWidth | DWORD | Horizontal Sync-Width in Pixel-Clks |
VBackPorch | DWORD | Vertical Back-Porch in Line-Clks |
VFrontPorch | DWORD | Vertical Front-Porch in Line-Clks |
VSyncWidth | DWORD | Vertical Sync-Width in Line-Clks |
SyncPolarity | DWORD | |
See Also
BitmapBoot Tool ( Trizeps II - V),
Connect a Display to a Trizeps,
Connect a LVDS Display to a Trizeps