Supported chipsets

# 1 Supported chipsets

Contents of this section

There are two different SVGA drivers for Cirrus chipsets, one called ``cirrus'' and one called ``cl64xx''. The ``cirrus'' driver is used in the 256-color SVGA server (with acceleration) and the mono server (without acceleration). The SVGA server supports 16 and 32 bits-per-pixel truecolor modes on some configurations. The ``cl64xx'' driver is used in the 256-color SVGA, 16-color and mono servers. Note that except where stated otherwise, this document is referring to the ``cirrus'' driver. The following chipsets by Cirrus Logic are supported:

CL-GD5420

  ISA SVGA chipset, 1Mbyte; maximum dot clock is 45 MHz (256 color server). Acceleration with extended write modes (used for scrolling and solid filling in this driver). This chipset can not support 1024x768 non-interlaced in 256 colors.

CL-GD5422

  Enhanced version of the 5420 (32-bit internal memory interface). Maximum dot clock is 80 MHz.

CL-GD6205/6215/6225/6235

  Laptop chipsets more or less compatible with the 5420. The only dot clock supported is 25 MHz (more on an external display). Some problems have been reported with these chipsets (especially on external displays). Take note of the "`noaccel`" option.

CL-GD6420/6440

  These chipsets are not compatible with the 542x series, but are supported by the ``cl64xx'' driver. It is used in recent laptops, and bears some similarity to old Cirrus chipsets (5410/AVGA2). The driver may also work for other 64xx chips. The configuration identifiers for this driver are "`cl6420`" and `"cl6440"`. This driver is discussed in detail in section The cl64xx Driver .

CL-GD5424

  Basically VLB version of the 5422, but resembles the 5426 in some respects.

CL-GD5426

  Supports both ISA bus and VLB, and up to 2Mbyte of memory. Has BitBLT engine for improved acceleration (BitBlt, image transfer, text). Dot clock limit is 85 MHz.

CL-GD5428

  Enhanced version of the 5426.

CL-GD5429

  Enhanced version of the 5428; officially supports higher MCLK and has memory-mapped I/O.

CL-GD5430

  Similar to 5429, but with 543x core (32-bit host interface). Does not have 64-bit memory mode.

CL-GD5434

  Next generation `Alpine' family chip with 64-bit internal memory interface. Used by the Orchid Kelvin 64. The chip can only support 64-bit mode if equipped with 2 Mbytes of memory; cards with only 1 Mbyte are severely limited. Support dot clocks up to 110 MHz.

Here's a list of maximum dot clocks for each supported depth:

>                     mono        8 bpp (256c)    16 bpp____      32 bpp
>     CL-GD62x5       45 MHz      45 MHz____
>     CL-GD5420       80 MHz      45 MHz (1)
>     CL-GD542x/512K  80 MHz      45 MHz____
>     CL-GD5422/24    80 MHz      80 MHz____      40 MHz____
>     CL-GD5426/28    85 MHz      85 MHz____      45 MHz (2)
>     CL-GD5429       85 MHz      85 MHz____      50 MHz____
>     CL-GD5430       85 MHz      85 MHz____      45 MHz (2)
>     CL-GD5434/1Mb   85 MHz      85 MHz____      45 MHz (2)
>     CL-GD5434/2Mb   85 MHz      85 MHz____      85 MHz____      45 MHz (2)

>     (1) with 512K memory.
>     (2) 50 MHz with high MCLK setting.

Rough virtual/physical screen resolution limits for different amounts of video memory:

>                 mono          8bpp          16 bpp        32 bpp
>     256K_       800x600__     640x400__     _________     ________
>     512K_       1152x900_     800x600__     640x400__     ________
>     1024K       1600x1200     1152x900_     800x600__     ________
>     2048K       2304x1728     1600x1200     1152x900_     800x600_
>     4096K       2304x1728     2272x1704     1600x1200     1152x900

The virtual width must be a multiple of 32 if acceleration is used. The horizontal monitor timings must be below 2048.

To run `XF86_SVGA` at 16 or 32 bpp, pass options to the X server as follows:

    startx -- -bpp 16               5-6-5 RGB ('64K color', XGA)
    startx -- -bpp 16 -weight 555   5-5-5 RGB ('Hicolor')
    startx -- -bpp 32               8-8-8 XRGB truecolor (5434)

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