path: root/README

  Information for Chips and Technologies Users
  David Bateman ( <mailto:dbateman@club-internet.fr>), Egbert
  Eich ( <mailto:eich@freedesktop.org>)
  1st January 2001
  ____________________________________________________________

  Table of Contents


  1. Introduction
  2. Supported Chips
     2.1 Basic architecture
     2.2 WinGine architecture
     2.3 HiQV Architecture

  3. xorg.conf Options
  4. Modelines
  5. Dual Display Channel
  6. The Full Story on Clock Limitations
  7. Troubleshooting
  8. Disclaimer
  9. Acknowledgement
  10. Authors


  ______________________________________________________________________

  1.  Introduction


  The Chips and Technologies driver release in X11R7.5 came from XFree86
  4.4 rc2; this document was originally included in that release and has
  been updated modestly to reflect differences between X11R7.5 and
  XFree86 4.4 rc2.

  With the release of XFree86 version 4.0, the Chips and Technologies
  driver has been extensively rewritten and contains many new features.
  This driver must be considered work in progress, and those users
  wanting stability are encouraged to use the older XFree86 3.3.x
  versions. However this version of the Chips and Technologies driver
  has many new features and bug fixes that might make users prefer to
  use this version. These features include


  o  The long standing black/blue screen problem that some people have
     had should be fixed.

  o  Hardware/Software cursor switching on the fly, that should fix many
     of the known hardware cursor problems.

  o  Gamma correction at all depths and DirectColor visuals for depths
     of 15 or greater with the HiQV series of chipsets.

  o  Supports PseudoColor overlays on 16bpp TrueColor screens for HiQV.

  o  Supports YUV colour space conversion with the XVideo extension.

  o  32bpp pixmaps while using a framebuffer in 24bpp packed pixel mode.

  o  Heaps more acceleration.

  o  1/4bpp support.

  o  Multihead


  o  Much more...

  This document attempts to discuss the features of this driver, the
  options useful in configuring it and the known problems. Most of the
  Chips and Technologies chipsets are supported by this driver to some
  degree.


  2.  Supported Chips


  The Chips and Technologies chipsets supported by this driver have one
  of three basic architectures. A basic architecture, the WinGine
  architecture which is a modification on this basic architecture and a
  completely new HiQV architecture.


  2.1.  Basic architecture


     ct65520
        (Max Ram: 1Mb, Max Dclk: 68MHz@5V)

     ct65525
        This chip is basically identical to the 65530. It has the same
        ID and is identified as a 65530 when probed. See ct65530 for
        details.

     ct65530
        This is a very similar chip to the 65520. However it
        additionally has the ability for mixed 5V and 3.3V operation and
        linear addressing of the video memory.  (Max Ram: 1Mb, Max Dclk:
        56MHz@3.3V, 68MHz@5V)

     ct65535
        This is the first chip of the ct655xx series to support fully
        programmable clocks. Otherwise it has the the same properties as
        the 65530.

     ct65540
        This is the first version of the of the ct655xx that was capable
        of supporting Hi-Color and True-Color. It also includes a fully
        programmable dot clock and supports all types of flat panels.
        (Max Ram: 1Mb, Max Dclk: 56MHz@3.3V, 68MHz@5V)

     ct65545
        The chip is very similar to the 65540, with the addition of H/W
        cursor, pop-menu acceleration, BitBLT and support of PCI Buses.
        PCI version also allow all the BitBLT and H/W cursor registers
        to be memory mapped 2Mb above the Base Address.  (Max Ram: 1Mb,
        Max Dclk: 56MHz@3.3V,68MHz@5V)

     ct65546
        This chip is specially manufactured for Toshiba, and so
        documentation is not widely available. It is believed that this
        is really just a 65545 with a higher maximum dot-clock of 80MHz.
        (Max Ram: 1Mb?, Max Dclk: 80MHz?)

     ct65548
        This chip is similar to the 65545, but it also includes XRAM
        support and supports the higher dot clocks of the 65546.  (Max
        Ram: 1Mb, Max Dclk: 80MHz)



  2.2.  WinGine architecture


     ct64200
        This chip, also known as the WinGine, is used in video cards for
        desktop systems. It often uses external DAC's and programmable
        clock chips to supply additional functionally. None of these are
        currently supported within the driver itself, so many cards will
        only have limited support. Linear addressing is not supported
        for this card in the driver.  (Max Ram: 2Mb, Max Dclk: 80MHz)

     ct64300
        This is a more advanced version of the WinGine chip, with
        specification very similar to the 6554x series of chips. However
        there are many differences at a register level. A similar level
        of acceleration to the 65545 is included for this driver.  (Max
        Ram: 2Mb, Max Dclk: 80MHz)


  2.3.  HiQV Architecture


     ct65550
        This chip includes many new features, including improved BitBLT
        support (24bpp colour expansion, wider maximum pitch, etc),
        Multimedia unit (video capture, zoom video port, etc) and 24bpp
        uncompressed true colour (i.e 32bpp mode). Also memory mapped
        I/O is possible on all bus configurations.  (Max Ram: 2Mb, Max
        Dclk: 80MHz@3.3V,100MHz@5V)

     ct65554
        This chip is similar to the 65550 but has a 64bit memory bus as
        opposed to a 32bit bus. It also has higher limits on the maximum
        memory and pixel clocks (Max Ram: 4Mb, Max Dclk: 100MHz@3.3V)

     ct65555
        Similar to the 65554 but has yet higher maximum memory and pixel
        clocks. It also includes a new DSTN dithering scheme that
        improves the performance of DSTN screens.  (Max Ram: 4Mb, Max
        Dclk: 110MHz@3.3V)

     ct68554
        Similar to the 65555 but also incorporates "PanelLink" drivers.
        This serial link allows an LCD screens to be located up to 100m
        from the video processor. Expect to see this chip soon in LCD
        desktop machines (Max Ram: 4Mb, Max Dclk: 110MHz@3.3V)

     ct69000
        Similar to the 65555 but incorporates 2Mbytes of SGRAM on chip.
        It is the first Chips and Technologies chipset where all of the
        registers are accessible through MMIO, rather than just the
        BitBlt registers.  (Max Ram: 2Mb Only, Max Dclk: 130MHz@3.3V)

     ct69030
        Similar to the 69000 but incorporates 4Mbytes of SGRAM on chip
        and has faster memory and pixel clock limits. Also includes a
        second display channel so that the CRT can display independently
        of the LCD.  (Max Ram: 4Mb Only, Max Dclk: 170MHz@3.3V)



  3.  xorg.conf Options


  The following options are of particular interest to the Chips and
  Technologies driver. It should be noted that the options are case
  insensitive, and that white space and "_" characters are ignored.
  There are therefore a wide variety of possible forms for all options.
  The forms given below are the preferred forms.

  Options related to drivers can be present in the Screen, Device and
  Monitor sections and the Display subsections. The order of precedence
  is Display, Screen, Monitor, Device.


     Option
        This option will disable the use of any accelerated functions.
        This is likely to help with some problems related to DRAM
        timing, high dot clocks, and bugs in accelerated functions, at
        the cost of performance (which will still be reasonable on
        VLB/PCI).

     VideoRam 1024 (or another value)
        This option will override the detected amount of video memory,
        and pretend the given amount of memory is present on the card.

     Option
        By default linear addressing is used on all chips where it can
        be set up automatically. The exception is for depths of 1 or
        4bpp where linear addressing is turned off by default.  It is
        possible to turn the linear addressing off with this option.
        Note that H/W acceleration is only supported with linear
        addressing.

     Option
        When the chipset is capable of linear addressing and it has been
        turned off by default, this option can be used to turn it back
        on. This is useful for the 65530 chipset where the base address
        of the linear framebuffer must be supplied by the user, or at
        depths 1 and 4bpp. Note that linear addressing at 1 and 4bpp is
        not guaranteed to work correctly.

     MemBase 0x03b00000 (or a different address)
        This sets the physical memory base address of the linear
        framebuffer. Typically this is probed correctly, but if you
        believe it to be mis-probed, this option might help.  Also for
        non PCI machines specifying this force the linear base address
        to be this value, reprogramming the video processor to suit.
        Note that for the 65530 this is required as the base address
        can't be correctly probed.

     Option
        For chipsets that support hardware cursors, this option enforces
        their use, even for cases that are known to cause problems on
        some machines. Note that it is overridden by the "SWcursor"
        option. Hardware cursors effectively speeds all graphics
        operations as the job of ensuring that the cursor remains on top
        is now given to the hardware. It also reduces the effect of
        cursor flashing during graphics operations.

     Option
        This disables use of the hardware cursor provided by the chip.
        Try this if the cursor seems to have problems.

     Option
        The server is unable to differentiate between SS STN and TFT
        displays. This forces it to identify the display as a SS STN
        rather than a TFT.

     Option
        The flat panel timings are related to the panel size and not the
        size of the mode specified in xorg.conf. For this reason the
        default behaviour of the server is to use the panel timings
        already installed in the chip. The user can force the panel
        timings to be recalculated from the modeline with this option.
        However the panel size will still be probed.

     Option
        For some machines the LCD panel size is incorrectly probed from
        the registers. This option forces the LCD panel size to be
        overridden by the modeline display sizes. This will prevent the
        use of a mode that is a different size than the panel. Before
        using this check that the server reports an incorrect panel
        size. This option can be used in conjunction with the option
        "UseModeline" to program all the panel timings using the
        modeline values.

     Option
        When the size of the mode used is less than the panel size, the
        default behaviour of the server is to stretch the mode in an
        attempt to fill the screen. A "letterbox" effect with no
        stretching can be achieved using this option.

     Option
        When the size of the mode used is less than the panel size, the
        default behaviour of the server is to align the left hand edge
        of the display with the left hand edge of the screen. Using this
        option the mode can be centered in the screen. This option is
        reported to have problems with some machines at 16/24/32bpp, the
        effect of which is that the right-hand edge of the mode will be
        pushed off the screen.

     Option
        For the chips either using the WinGine or basic architectures,
        the chips generates a number of fixed clocks internally. With
        the chips 65535 and later or the 64300, the default is to use
        the programmable clock for all clocks. It is possible to use the
        fixed clocks supported by the chip instead by using this option.
        Typically this will give you some or all of the clocks 25.175,
        28.322, 31.000 and 36.000MHz. The current programmable clock
        will be given as the last clock in the list. On a cold-booted
        system this might be the appropriate value to use at the text
        console (see the "TextClockFreq" option), as many flat panels
        will need a dot clock different than the default to synchronise.
        The programmable clock makes this option obsolete and so it's
        use isn't recommended. It is completely ignored for HiQV
        chipsets.

     TextClockFreq 25.175
        Except for the HiQV chipsets, it is impossible for the server to
        read the value of the currently used frequency for the text
        console when using programmable clocks. Therefore the server
        uses a default value of 25.175MHz as the text console clock. For
        some LCDs, in particular DSTN screens, this clock will be wrong.
        This allows the user to select a different clock for the server
        to use when returning to the text console.

     Option
        Option "FPClock16" "65.0MHz" Option "FPClock24" "65.0MHz" Option
        "FPClock32" "65.0MHz"" In general the LCD panel clock should be
        set independently of the modelines supplied. Normally the chips
        BIOS set the flat panel clock correctly and so the default
        behaviour with HiQV chipset is to leave the flat panel clock
        alone, or force it to be 90% of the maximum allowable clock if
        the current panel clock exceeds the dotclock limitation due to a
        depth change. This option allows the user to force the server
        the reprogram the flat panel clock independently of the modeline
        with HiQV chipset. The four options are for 8bpp or less, 16, 24
        or 32bpp LCD panel clocks, where the options above set the
        clocks to 65MHz.

     Option
        Option "FPClkIndx" "1"" The HiQV series of chips have three
        programmable clocks. The first two are usually loaded with
        25.175 and 28.322MHz for VGA backward compatibility, and the
        third is used as a fully programmable clock. On at least one
        system (the Inside 686 LCD/S single board computer) the third
        clock is unusable. These options can be used to force a
        particular clock index to be used

     Option
        This has a different effect depending on the hardware on which
        it is used. For the 6554x machines MMIO is only used to talk to
        the BitBLT engine and is only usable with PCI buses. It is
        enabled by default for 65545 machines since the blitter can not
        be used otherwise. The HiQV series of chipsets must use MMIO
        with their BitBLT engines, and so this is enabled by default.

     Option
        The 690xx chipsets can use MMIO for all communications with the
        video processor. So using this option on a 690xx chipset forces
        them to use MMIO for all communications. This only makes sense
        when the 690xx is on a PCI bus so that normal PIO can be
        disabled.

     Option
        This option sets the centering and stretching to the BIOS
        default values. This can fix suspend/resume problems on some
        machines. It overrides the options "LcdCenter" and "NoStretch".

     Option            For 24bpp on TFT screens, the server assumes that
                       a 24bit bus is being used. This can result in a
                       reddish tint to 24bpp mode.  This option, selects
                       an 18 bit TFT bus. For other depths this option
                       has no effect.

     Chipset           It is possible that the chip could be
                       misidentified, particular due to interactions
                       with other drivers in the server. It is possible
                       to force the server to identify a particular chip
                       with this option.

     Option            Composite sync on green. Possibly useful if you
                       wish to use an old workstation monitor. The HiQV
                       internal RAMDAC's supports this mode of
                       operation, but whether a particular machine does
                       depends on the manufacturer.

     DacSpeed 80.000   The server will limit the maximum dotclock to a
                       value as specified by the manufacturer. This
                       might make certain modes impossible to obtain
                       with a reasonable refresh rate. Using this option
                       the user can override the maximum dot-clock and
                       specify any value they prefer. Use caution with
                       this option, as driving the video processor
                       beyond its specifications might cause damage.

     Option            Option "SetMClk" "38000kHz"" This option sets the
                       internal memory clock (MCLK) registers of HiQV
                       chipsets to 38MHz or some other value. Use
                       caution as excess heat generated by the video
                       processor if its specifications are exceeded
                       might cause damage. However careful use of this
                       option might boost performance. This option might
                       also be used to reduce the speed of the memory
                       clock to preserve power in modes that don't need
                       the full speed of the memory to work correctly.
                       This option might also be needed to reduce the
                       speed of the memory clock with the "Overlay"
                       option.

     Option            By default it is assumed that there are 6
                       significant bits in the RGB representation of the
                       colours in 4bpp and above. If the colours seem
                       darker than they should be, perhaps your ramdac
                       is has 8 significant bits. This option forces the
                       server to assume that there are 8 significant
                       bits.

     Option            This is a debugging option and general users have
                       no need of it.  Using this option, when the
                       virtual desktop is scrolled away from the zero
                       position, the pixmap cache becomes visible. This
                       is useful to see that pixmaps, tiles, etc have
                       been properly cached.

     Option            This option is only useful when acceleration
                       can't be used and linear addressing can be used.
                       With this option all of the graphics are rendered
                       into a copy of the framebuffer that is keep in
                       the main memory of the computer, and the screen
                       is updated from this copy. In this way the
                       expensive operation of reading back to contents
                       of the screen is never performed and the
                       performance is improved. Because the rendering is
                       all done into a virtual framebuffer acceleration
                       can not be used.

     Option            The new TMED DSTN dithering scheme available on
                       recent HiQV chipsets gives improved performance.
                       However, some machines appear to have this
                       feature incorrectly setup. If you have snow on
                       your DSTN LCD, try using this option. This option
                       is only relevant for chipsets more recent than
                       the ct65555 and only when used with a DSTN LCD.

     Option            The HiQV chipsets contain a multimedia engine
                       that allow a 16bpp window to be overlaid on the
                       screen. This driver uses this capability to
                       include a 16bpp framebuffer on top of an 8bpp
                       framebuffer. In this way PseudoColor and
                       TrueColor visuals can be used on the same screen.
                       XFree86 believes that the 8bpp framebuffer is
                       overlaid on the 16bpp framebuffer. Therefore to
                       use this option the server must be started in
                       either 15 or 16bpp depth. Also the maximum size
                       of the desktop with this option is 1024x1024, as
                       this is the largest window that the HiQV
                       multimedia engine can display. Note that this
                       option using the multimedia engine to its limit,
                       and some manufacturers have set a default memory
                       clock that will cause pixel errors with this
                       option.  If you get pixel error with this option
                       try using the "SetMClk" option to slow the memory
                       clock. It should also be noted that the XVideo
                       extension uses the same capabilities of the HiQV
                       chipsets as the Overlays. So using this option
                       disables the XVideo extension.


     Option            Normally the colour transparency key for the
                       overlay is the 8bpp lookup table entry 255. This
                       might cause troubles with some applications, and
                       so this option allows the colour transparency key
                       to be set to some other value. Legal values are 2
                       to 255 inclusive.

     Option            This sets the default pixel value for the YUV
                       video overlay key. Legal values for this key are
                       depth dependent. That is from 0 to 255 for 8bit
                       depth, 0 to 32,767 for 15bit depth, etc. This
                       option might be used if the default video overlay
                       key causes problems.

     Option            The 69030 chipset has independent display
                       channels, that can be configured to support
                       independent refresh rates on the flat panel and
                       on the CRT. The default behaviour is to have both
                       the flat panel and the CRT use the same display
                       channel and thus the same refresh rate. This
                       option forces the two display channels to be
                       used, giving independent refresh rates.

     Option            The ct69030 supports dual-head display. By
                       default the two display share equally the
                       available memory. This option forces the second
                       display to take a particular amount of memory.
                       Please read the section below about dual-head
                       display.

     Option            Option "XaaNoSolidFillRect", Option "XaaNoSolid-
                       HorVertLine", Option "XaaNoMono8x8PatternFill-
                       Rect", Option "XaaNoColor8x8PatternFillRect",
                       Option "XaaNoCPUToScreenColorExpandFill", Option
                       "XaaNoScreenToScreenColorExpandFill", Option
                       "XaaNoImageWriteRect", Option "XaaNoImageRead-
                       Rect", Option "XaaNoPixmapCache", Option
                       "XaaNoOffscreenPixmaps" " These option
                       individually disable the features of the XAA
                       acceleration code that the Chips and Technologies
                       driver uses. If you have a problem with the
                       acceleration and these options will allow you to
                       isolation the problem. This information will be
                       invaluable in debugging any problems.


  4.  Modelines


  When constructing a modeline for use with the Chips and Technologies
  driver you'll needed to considered several points


      * Virtual Screen Size
        It is the virtual screen size that determines the amount of
        memory used by a mode. So if you have a virtual screen size set
        to 1024x768 using a 800x600 at 8bpp, you use 768kB for the mode.
        Further to this some of the XAA acceleration requires that the
        display pitch is a multiple of 64 pixels. So the driver will
        attempt to round-up the virtual X dimension to a multiple of 64,
        but leave the virtual resolution untouched. This might further
        reduce the available memory.

      * 16/24/32 Bits Per Pixel
        Hi-Color and True-Color modes are implemented in the server. The
        clocks in the 6554x series of chips are internally divided by 2
        for 16bpp and 3 for 24bpp, allowing one modeline to be used at
        all depths. The effect of this is that the maximum dot clock
        visible to the user is a half or a third of the value at 8bpp.
        The HiQV series of chips doesn't need to use additional clock
        cycles to display higher depths, and so the same modeline can be
        used at all depths, without needing to divide the clocks.  Also
        16/24/32 bpp modes will need 2 , 3 or 4 times respectively more
        video ram.

      * Frame Acceleration
        Many DSTN screens use frame acceleration to improve the
        performance of the screen. This can be done by using an external
        frame buffer, or incorporating the framebuffer at the top of
        video ram depending on the particular implementation. The
        Xserver assumes that the framebuffer, if used, will be at the
        top of video ram.  The amount of ram required for the
        framebuffer will vary depending on the size of the screen, and
        will reduce the amount of video ram available to the modes.
        Typical values for the size of the framebuffer will be 61440
        bytes (640x480 panel), 96000 bytes (800x600 panel) and 157287
        bytes (1024x768 panel).

      * H/W Acceleration
        The H/W cursor will need 1kB for the 6554x and 4kb for the
        65550. On the 64300 chips the H/W cursor is stored in registers
        and so no allowance is needed for the H/W cursor. In addition to
        this many graphics operations are speeded up using a "pixmap
        cache". Leaving too little memory available for the cache will
        only have a detrimental effect on the graphics performance.

      * PseudoColor Overlay
        If you use the "overlay" option, then there are actually two
        framebuffers in the video memory. An 8bpp one and a 16bpp one.
        The total memory requirements in this mode of operation is
        therefore similar to a 24bpp mode. The overlay consumes memory
        bandwidth, so that the maximum dotclock will be similar to a
        24bpp mode.

      * XVideo extension*
        Like the overlays, the Xvideo extension uses a part of the video
        memory for a second framebuffer. In this case enough memory
        needs to be left for the largest unscaled video window that will
        be displayed.

      * VESA like modes
        We recommend that you try and pick a mode that is similar to a
        standard VESA mode. If you don't a suspend/resume or LCD/CRT
        switch might mess up the screen. This is a problem with the
        video BIOS not knowing about all the funny modes that might be
        selected.

      * Dot Clock
        For LCD screens, the lowest clock that gives acceptable contrast
        and flicker is usually the best one. This also gives more memory
        bandwidth for use in the drawing operations. Some users prefer
        to use clocks that are defined by their BIOS. This has the
        advantage that the BIOS will probably restore the clock they
        specified after a suspend/resume or LCD/CRT switch. For a
        complete discussion on the dot clock limitations, see the next
        section.

      * Dual-head display
        Dual-head display has two effects on the modelines. Firstly, the
        memory requirements of both heads must fit in the available
        memory. Secondly, the memory bandwidth of the video processor is
        shared between the two heads. Hence the maximum dot-clock might
        need to be limited.

  The driver is capable of driving both a CRT and a flat panel display.
  In fact the timing for the flat panel are dependent on the
  specification of the panel itself and are independent of the
  particular mode chosen. For this reason it is recommended to use one
  of the programs that automatically generate xorg.conf files, such as
  "xorgconfig".

  However there are many older machines, particularly those with 800x600
  screen or larger, that need to reprogram the panel timings. The reason
  for this is that the manufacturer has used the panel timings to get a
  standard EGA mode to work on flat panel, and these same timings don't
  work for an SVGA mode. For these machines the "UseModeline" and/or
  possibly the "FixPanelSize" option might be needed. Some machines that
  are known to need these options include.



       Modeline "640x480@8bpp"       25.175  640  672  728  816   480  489  501  526
       Modeline "640x480@16bpp"  25.175  640  672  728  816   480  489  501  526
       Options: "UseModeline"
       Tested on a Prostar 8200, (640x480, 65548, 1Mbyte)



       Modeline "800x600@8bpp"       28.322  800  808  848  936   600  600  604  628
       Options: "FixPanelSize", "UseModeline"
       Tested on a HP OmniBook 5000CTS (800x600 TFT, 65548, 1Mbyte)



       Modeline "800x600@8bpp"       30.150  800  896  960 1056   600  600  604  628
       Options: "FixPanelSize", "UseModeline"
       Tested on a Zeos Meridan 850c (800x600 DSTN, 65545, 1Mbyte)



  The IBM PC110 works best with a 15MHz clock (Thanks to Alan Cox):


       Modeline "640x480"        15.00   640  672  728  816   480  489  496  526
       Options: "TextClockFreq" "15.00"
       IBM PC110 (65535, Citizen L6481L-FF DSTN)



  The NEC Versa 4080 just needs the "FixPanelSize" option. To the best
  of my knowledge no machine with a HiQV needs the "UseModeline" or
  "FixPanelSize" options.


  5.  Dual Display Channel


  XFree86 releases later than 4.1.0 and X.Org releases later than 6.7.0
  support dual-channel display on the ct69030. This support can be used
  to give a single display image on two screen with different refresh
  rates, or entirely different images on the two displays.

  Dual refresh rate display can be selected with the "DualRefresh"
  option described above. However to use the dual-head support is
  slightly more complex. Firstly, the ct69030 chipset must be installed
  on a PCI bus. This is a driver limitation that might be relaxed in the
  future. In addition the device, screen and layout sections of the
  "xorg.conf" must be correctly configured. A sample of an incomplete
  "xorg.conf" is given below



       Section "Device"
           Identifier  "Chips and Technologies - Pipe A"
           Driver      "chips"
           BusID       "PCI:0:20:0"
           Screen      0
       EndSection

       Section "Device"
           Identifier  "Chips and Technologies - Pipe B"
           Driver      "chips"
           BusID       "PCI:0:20:0"
           Screen      1
       EndSection

       Section "Screen"
           Identifier  "Screen 0"
           Device      "Chips and Technologies - Pipe A"
           Monitor     "generic LCD"

           SubSection "Display"
               Depth           16
               Modes           "1024x768"
           EndSubsection
       EndSection

       Section "Screen"
           Identifier  "Screen 1"
           Device      "Chips and Technologies - Pipe B"
           Monitor     "generic CRT"

           SubSection "Display"
               Depth           16
               Modes           "1024x768"
           EndSubsection
       EndSection

       Section "ServerLayout"
           Identifier  "Main Layout"
           Screen      "Screen 0"
           Screen      "Screen 1" RightOf "Screen 0"
           InputDevice "Mouse1" "CorePointer"
           InputDevice "Keyboard1" "CoreKeyboard"
       EndSection



  The device section must include the PCI BusID. This can be found from
  the log file of a working single-head installation. For instance, the
  line



  (--) PCI:*(0:20:0) C&T 69030 rev 97, Mem @ 0xed000000/24



  appears for the case above. Additionally, the "Screen" option must
  appear in the device section. It should be noted that if a flat panel
  is used, this it must be allocated to "Screen 0".

  The server can then be started with the "+xinerama" option as follows



       startx -- +xinerama



  For more information, read the Xinerama documentation.

  It should be noted that the dual channel display options of the 69030
  require the use of additional memory bandwidth, as each display
  channel independently accesses the video memory. For this reason, the
  maximum colour depth and resolution that can be supported in a dual
  channel mode will be reduced compared to a single display channel
  mode. However, as the driver does not prevent you from using a mode
  that will exceed the memory bandwidth of the 69030, but a warning like



       (WW) Memory bandwidth requirements exceeded by dual-channel
       (WW)    mode. Display might be corrupted!!!



  If you see such display corruption, and you have this warning, your
  choices are to reduce the refresh rate, colour depth or resolution, or
  increase the speed of the memory clock with the the "SetMClk" option
  described above. Note that increasing the memory clock also has its
  own problems as described above.


  6.  The Full Story on Clock Limitations


  There has been much confusion about exactly what the clock limitations
  of the Chips and Technologies chipsets are. Hence I hope that this
  section will clear up the misunderstandings.

  In general there are two factors determining the maximum dotclock.
  There is the limit of the maximum dotclock the video processor can
  handle, and there is another limitation of the available memory
  bandwidth. The memory bandwidth is determined by the clock used for
  the video memory.  For chipsets incapable of colour depths greater
  that 8bpp like the 65535, the dotclock limit is solely determined by
  the highest dotclock the video processor is capable of handling. So
  this limit will be either 56MHz or 68MHz for the 655xx chipsets,
  depending on what voltage they are driven with, or 80MHz for the 64200
  WinGine machines.

  The 6554x and 64300 WinGine chipsets are capable of colour depths of
  16 or 24bpp. However there is no reliable way of probing the memory
  clock used in these chipsets, and so a conservative limit must be
  taken for the dotclock limit. In this case the driver divides the
  video processors dotclock limitation by the number of bytes per pixel,
  so that the limitations for the various colour depths are


                          8bpp    16bpp   24bpp
  64300                   85      42.5    28.33
  65540/65545 3.3v        56      28      18.67
  65540/65545 5v          68      34      22.67
  65546/65548             80      40      26.67



  For a CRT or TFT screen these limitations are conservative and the
  user might safely override them with the "DacSpeed" option to some
  extent. However these numbers take no account of the extra bandwidth
  needed for DSTN screens.

  For the HiQV series of chips, the memory clock can be successfully
  probed.  Hence you will see a line like


  (--) CHIPS(0): Probed memory clock of  40.090 MHz



  in your startx log file. Note that many chips are capable of higher
  memory clocks than actually set by BIOS. You can use the "SetMClk"
  option in your xorg.conf file to get a higher MClk. However some video
  ram, particularly EDO, might not be fast enough to handle this,
  resulting in drawing errors on the screen. The formula to determine
  the maximum usable dotclock on the HiQV series of chips is


  Max dotclock = min(MaxDClk,  0.70  * 8 * MemoryClk / (BytesPerPixel +
                  (isDSTN == TRUE ? 1 : 0)))



  if you chips is a 69030 or 69000 or


  Max dotclock = min(MaxDClk,  0.70  * 4 * MemoryClk / (BytesPerPixel +
                  (isDSTN == TRUE ? 1 : 0)))



  otherwise. This effectively means that there are two limits on the
  dotclock. One the overall maximum, and another due to the available
  memory bandwidth of the chip. The 69030 and 69000 have a 64bit memory
  bus and thus transfer 8 bytes every clock thus (hence the 8), while
  the other HiQV chipsets are 32bit and transfer 4 bytes per clock cycle
  (hence the 4). However, after accounting for the RAS/CAS signaling
  only about 70% of the bandwidth is available. The whole thing is
  divided by the bytes per pixel, plus an extra byte if you are using a
  DSTN. The extra byte with DSTN screens is used for the frame
  buffering/acceleration in these screens. So for the various Chips and
  Technologies chips the maximum specifications are



                      Max DClk MHz      Max Mem Clk MHz
  65550 rev A 3.3v          80                38
  65550 rev A 5v           110                38
  65550 rev B               95                50
  65554                     94.5              55
  65555                    110                55
  68554                    110                55
  69000                    135                83
  69030                    170               100



  Note that all of the chips except the 65550 rev A are 3.3v only. Which
  is the reason for the drop in the dot clock. Now the maximum memory
  clock is just the maximum supported by the video processor, not the
  maximum supported by the video memory. So the value actually used for
  the memory clock might be significantly less than this maximum value.
  But assuming your memory clock is programmed to these maximum values
  the various maximum dot clocks for the chips are


                          ------CRT/TFT-------    --------DSTN--------
                          8bpp    16bpp   24bpp   8bpp    16bpp   24bpp
  65550 rev A 3.3v        80      53.2    35.47   53.2    35.47   26.6
  65550 rev A 5v          106.2   53.2    35.47   53.2    35.47   26.6
  65550 rev B             95      70      46.67   70      46.67   35.0
  65554                   94.5    77      51.33   77      51.33   38.5
  65555                   110     77      51.33   77      51.33   38.5
  68554                   110     77      51.33   77      51.33   38.5
  69000                   135    135     135     135     135     116.2
  69030                   170    170     170     170     170     140



  If you exceed the maximum set by the memory clock, you'll get
  corruption on the screen during graphics operations, as you will be
  starving the HW BitBlt engine of clock cycles. If you are driving the
  video memory too fast (too high a MemClk) you'll get pixel corruption
  as the data actually written to the video memory is corrupted by
  driving the memory too fast. You can probably get away with exceeding
  the Max DClk at 8bpp on TFT's or CRT's by up to 10% or so without
  problems, it will just generate more heat, since the 8bpp clocks
  aren't limited by the available memory bandwidth.

  If you find you truly can't achieve the mode you are after with the
  default clock limitations, look at the options "DacSpeed" and
  "SetMClk". Using these should give you all the capabilities you'll
  need in the server to get a particular mode to work. However use
  caution with these options, because there is no guarantee that driving
  the video processor beyond it capabilities won't cause damage.


  7.  Troubleshooting



      The cursor appears as a white box, after switching modes
        There is a known bug in the H/W cursor, that sometimes causes
        the cursor to be redrawn as a white box, when the mode is
        changed.  This can be fixed by moving the cursor to a different
        region, switching to the console and back again, or if it is too
        annoying the H/W cursor can be disabled by removing the
        "HWcursor" option.

      The cursor hot-spot isn't at the same point as the cursor
        With modes on the 6555x machines that are stretched to fill the
        flat panel, the H/W cursor is not correspondingly stretched.
        This is a small and long-standing bug in the current server. You
        can avoid this by either using the "NoStretch" option or
        removing the HWcursor" option.

      The lower part of the screen is corrupted
        Many DSTN screens use the top of video ram to implement a frame
        accelerator. This reduces the amount of video ram available to
        the modes. The server doesn't prevent the user from specifying a
        mode that will use this memory, it prints a warning on the
        console.  The effect of this problem will be that the lower part
        of the screen will reside in the same memory as the frame
        accelerator and will therefore be corrupt. Try reducing the
        amount of memory consumed by the mode.

      There is a video signal, but the screen doesn't sync.
        You are using a mode that your screen cannot handle. If it is a
        non-standard mode, maybe you need to tweak the timings a bit. If
        it is a standard mode and frequency that your screen should be
        able to handle, try to find different timings for a similar mode
        and frequency combination. For LCD modes, it is possible that
        your LCD panel requires different panel timings at the text
        console than with a graphics mode. In this case you will need
        the "UseModeline" and perhaps also the "FixPanelSize" options to
        reprogram the LCD panel timings to sensible values.

      `Wavy' screen.
        Horizontal waving or jittering of the whole screen, continuously
        (independent from drawing operations). You are probably using a
        dot clock that is too high (or too low); it is also possible
        that there is interference with a close MCLK. Try a lower dot
        clock.  For CRT's you can also try to tweak the mode timings;
        try increasing the second horizontal value somewhat.

      Crash or hang after start-up (probably with a black screen).
        Try the "NoAccel" or one of the XAA acceleration options
        discussed above. Check that the BIOS settings are OK; in
        particular, disable caching of 0xa0000-0xaffff. Disabling hidden
        DRAM refresh may also help.

      Hang as the first text is appearing on the screen on SVR4
        machines.
        This problem has been reported under UnixWare 1.x, but not
        tracked down. It doesn't occur under UnixWare 2.x and only
        occurs on the HiQV series of chips. It might affect some other
        SVR4 operating systems as well. The workaround is to turn off
        the use of CPU to screen acceleration with the
        "XaaNoCPUToScreenColorExapndFill" option.

      Crash, hang, or trash on the screen after a graphics operation.
        This may be related to a bug in one of the accelerated
        functions, or a problem with the BitBLT engine. Try the
        "NoAccel" or one of the XAA acceleration options discussed
        above. Also check the BIOS settings. It is also possible that
        with a high dot clock and depth on a large screen there is very
        little bandwidth left for using the BitBLT engine. Try reducing
        the clock.

      Chipset is not detected.
        Try forcing the chipset to a type that is most similar to what
        you have.

     The screen is blank when starting X
        One possible cause of this problem with older linux kernels is
        that the "APM_DISPLAY_BLANK" option didn't work correct. Either
        upgrade your kernel or rebuild it with the "APM_DISPLAY_BLANK"
        option disabled. If the problem remains, or you aren't using
        linux, a CRT/LCD or switch to and from the virtual console will
        often fix it.

      Textmode is not properly restored
        This has been reported on some configurations. Many laptops use
        the programmable clock of the 6554x chips at the console.  It is
        not always possible to find out the setting that is used for
        this clock if BIOS has written the MClk after the VClk. Hence
        the server assumes a 25.175MHz clock at the console. This is
        correct for most modes, but can cause some problems. Usually
        this is fixed by switching between the LCD and CRT.
        Alternatively the user can use the "TextClockFreq" option
        described above to select a different clock for the text
        console. Another possible cause of this problem is if linux
        kernels are compiled with the "APM_DISPLAY_BLANK" option.  As
        mentioned before, try disabling this option.

      I can't display 640x480 on my 800x600 LCD
        The problem here is that the flat panel needs timings that are
        related to the panel size, and not the mode size. There is no
        facility in the current Xservers to specify these values, and so
        the server attempts to read the panel size from the chip. If the
        user has used the "UseModeline" or "FixPanelSize" options the
        panel timings are derived from the mode, which can be different
        than the panel size. Try deleting these options from xorg.conf
        or using an LCD/CRT switch.

      I can't get a 320x240 mode to occupy the whole 640x480 LCD
        There is a bug in the 6554x's H/W cursor for modes that are
        doubled vertically. The lower half of the screen is not
        accessible.  The servers solution to this problem is not to do
        doubling vertically.  Which results in the 320x240 mode only
        expanded to 640x360. If this is a problem, a work around is to
        remove the "HWcursor" option. The server will then allow the
        mode to occupy the whole 640x480 LCD.

      After a suspend/resume my screen is messed up
        During a suspend/resume, the BIOS controls what is read and
        written back to the registers. If the screen is using a mode
        that BIOS doesn't know about, then there is no guarantee that it
        will be resumed correctly. For this reason a mode that is as
        close to VESA like as possible should be selected. It is also
        possible that the VGA palette can be affected by a
        suspend/resume.  Using an 8bpp, the colour will then be
        displayed incorrectly. This shouldn't affect higher depths, and
        is fixable with a switch to the virtual console and back.

      The right hand edge of the mode isn't visible on the LCD
        This is usually due to a problem with the "LcdCenter" option. If
        this option is removed form xorg.conf, then the problem might go
        away. Alternatively the manufacturer could have incorrectly
        programmed the panel size in the EGA console mode. The
        "FixPanelSize" can be used to force the modeline values into the
        panel size registers. Two machines that are known to have this
        problem are the "HP OmniBook 5000" and the "NEC Versa 4080".

      My TFT screen has a reddish tint in 24bpp mode
        For 6554x chipsets the server assumes that the TFT bus width is
        24bits. If this is not true then the screen will appear to have
        a reddish tint. This can be fixed by using the "18BitBus"
        option. Note that the reverse is also true. If the "18BitBus" is
        used and the TFT bus width is 24bpp, then the screen will appear
        reddish. Note that this option only has an effect on TFT
        screens.

      SuperProbe won't work with my chipset
        At least one non-PCI bus system with a HiQV chipset has been
        found to require the "-no_bios" option for SuperProbe to
        correctly detect the chipset with the factory default BIOS
        settings. The server itself can correctly detect the chip in the
        same situation.

      My 690xx machine lockups when using the
        The 690xx MMIO mode has been implemented entirely from the
        manual as I don't have the hardware to test it on. At this point
        no testing has been done and it is entirely possible that the
        "MMIO option will lockup your machine. You have been warned!
        However if you do try this option and are willing to debug it,
        I'd like to hear from you.

      My TrueColor windows are corrupted when using the
        Chips and Technologies specify that the memory clock used with
        the multimedia engine running should be lower than that used
        without. As use of the HiQV chipsets multimedia engine was
        supposed to be for things like zoomed video overlays, its use
        was supposed to be occasional and so most machines have their
        memory clock set to a value that is too high for use with the
        "Overlay" option. So with the "Overlay" option, using the
        "SetMClk" option to reduce the speed of the memory clock is
        recommended.

      The mpeg video playing with the XVideo extension has corrupted
        colours
        The XVideo extension has only recently been added to the chips
        driver.  Some YUV to RGB colour have been noted at 15 and 16 bit
        colour depths.  However, 8 and 24 bit colour depths seem to work
        fine.

      My ct69030 machine locks up when starting X
        The ct69030 chipset introduced a new dual channel architecture.
        In its current form, X can not take advantage of this second
        display channel. In fact if the video BIOS on the machine sets
        the ct69030 to a dual channel mode by default, X will lockup
        hard at this point. The solution is to use the BIOS setup to
        change to a single display channel mode, ensuring that both the
        IOSS and MSS registers are set to a single channel mode. Work is
        underway to fix this.

      I can't start X-windows with 16, 24 or 32bpp
        Firstly, is your machine capable of 16/24/32bpp with the mode
        specified. Many LCD displays are incapable of using a 24bpp
        mode. Also you need at least a 65540 to use 16/24bpp and at
        least a 65550 for 32bpp. The amount of memory used by the mode
        will be doubled/tripled/quadrupled. The correct options to start
        the server with these modes are


                  startx -- -depth 16             5-6-5 RGB ('64K color', XGA)
                  startx -- -depth 15             5-5-5 RGB ('Hicolor')
                  startx -- -depth 24             8-8-8 RGB truecolor


     or with the HiQV series of chips you might try

               startx -- -depth 24 -fbbpp 32   8-8-8 RGB truecolor


     however as X11R7.5 allows 32bpp pixmaps to be used with frame-
     buffers operating in 24bpp, this mode of operating will cost per-
     formance for no gain in functionality.

     Note that the "-bpp" option has been removed and replaced with a
     "-depth" and "-fbbpp" option because of the confusion between the
     depth and number of bits per pixel used to represent to framebuffer
     and the pixmaps in the screens memory.

  A general problem with the server that can manifested in many way such
  as drawing errors, wavy screens, etc is related to the programmable
  clock. Many potential programmable clock register setting are
  unstable.  However luckily there are many different clock register
  setting that can give the same or very similar clocks. The clock code
  can be fooled into giving a different and perhaps more stable clock by
  simply changing the clock value slightly. For example 65.00MHz might
  be unstable while 65.10MHz is not. So for unexplained problems not
  addressed above, please try to alter the clock you are using slightly,
  say in steps of 0.05MHz and see if the problem goes away.
  Alternatively, using the "CRTClkIndx" or "FPClkIndx" option with HiQV
  chips might also help.


  For other screen drawing related problems, try the "NoAccel" or one of
  the XAA acceleration options discussed above. A useful trick for all
  laptop computers is to switch between LCD/CRT (usually with something
  like Fn-F5), if the screen is having problems.

  If you are having driver-related problems that are not addressed by
  this document, or if you have found bugs in accelerated functions, you
  can try contacting the Xorg team (the current driver maintainer can be
  reached at  <mailto:eich@freedesktop.org>).


  8.  Disclaimer


  The Xorg X server, allows the user to do damage to their hardware with
  software with old monitors which may not tolerate bad display
  settings.  Although the authors of this software have tried to prevent
  this, they disclaim all responsibility for any damage caused by the
  software. Use caution, if you think the X server is frying your
  screen, TURN THE COMPUTER OFF!!


  9.  Acknowledgement


  The authors of this software wish to acknowledge the support supplied
  by Chips and Technologies during the development of this software.


  10.  Authors


  Major Contributors (In no particular order)

  o  Nozomi Ytow

  o  Egbert Eich

  o  David Bateman

  o  Xavier Ducoin

  Contributors (In no particular order)

  o  Ken Raeburn


  o  Shigehiro Nomura

  o  Marc de Courville

  o  Adam Sulmicki

  o  Jens Maurer

  We also thank the many people on the net who have contributed by
  reporting bugs and extensively testing this server.