Information for Cirrus Chipset Users : Supported chipsets
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## 1. Supported chipsets

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, 24, 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

  `Alpine' family chip with 64-bit internal memory interface. The chip can only support 64-bit mode if equipped with 2 Mbytes of memory; cards with only 1 Mbyte are severely limited. Supports dot clocks up to 110 MHz (later chips support 135 MHz).

CL-GD5436

  Highly optimized 5434.

CL-GD5440

  Similar to the CL-GD5430, and detected as such.

CL-GD5446

  Another member of the Alpine family of 2D accelerators; similar to the CL-GD5436.

CL-GD5480

  Newer Alpine family chip that support synchronous graphics RAM (SGRAM).

CL-GD5462, CL-GD5464 and CL-GD5465

  The Laguna VisualMedia family of 2D Accelerators. These chips use Rambus RDRAM memory. The '62 is a 64-bit 2D accelerator, including a BitBlit engine, video windows (not currently used by the server), and 64x64 HW cursor. Mono modes have not been tested. The CL-GD5464 is the next chip in the Laguna family, and the CL-GD5465 is the latest member, both have been tested.

CL-GD7541/7542/7543/7548

  Laptop chipsets more or less compatible with the 5428/3x. While has it been tested on some configurations, not all configuration may work correctly.

CL-GD7555

  Limited untested support, without auto-detection, has been provided for this chip which is a 64-bit extension of the 754x family. Use a Chipset "clgd7555" line.

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

>                     mono     8 bpp (256c) 16 bpp       24 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       27 MHz
>     CL-GD5426/28    85 MHz   85 MHz       45 MHz (2)   28 MHz
>     CL-GD5429       85 MHz   85 MHz       50 MHz       28 MHz
>     CL-GD5430       85 MHz   85 MHz       45 MHz (2)   28 MHz
>     CL-GD5434/1Mb   85 MHz   85 MHz       42 MHz       28 MHz
>     CL-GD5434/2Mb   85 MHz   110/135 MHz  85 MHz       28 MHz       45/50 MHz (2)
>     CL-GD5436/1Mb	85 MHz	 110 MHz (3)  60 MHz (3)   40 MHz (3)
>     CL-GD5436/2Mb	85 MHz	 135 MHz      85 MHz       85 MHz (3)   60 MHz (3)
>     CL-GD5446/1Mb	85 MHz	 110 MHz (3)  60 MHz (3)   40 MHz (3)
>     CL-GD5446/2Mb	85 MHz	 135 MHz      85 MHz       85 MHz (3)   60 MHz (3)
>     CL-GD5462	170 MHz  170 Mhz      170 MHz      170 MHz      135 MHz
>     CL-GD5464/65	170 MHz  230 Mhz      170 MHz      170 MHz      135 MHz
>     CL-GD5480	85 MHz	 200 MHz      100 MHz      100 MHz      50 MHz
>     CL-GD754x	80 MHz   80 MHz       40 MHz (4)   (5)

>     (1) with 512K memory.
>     (2) 50 MHz with high MCLK setting.
>     (3) Depends on memory clock.
>     (4) This may be too low for some chips.
>     (5) This depth may actually work if it is enabled and tested.

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

>                 mono        8 bpp        16 bpp     24 bpp     32 bpp
>     256K        800x600     640x400
>     512K        1152x900    800x600     640x400
>     1024K       1600x1200   1152x900    800x600     680x510
>     2048K       2304x1728   1600x1200   1152x900    960x720    800x600
>     4096K       2304x1728   2272x1704   1600x1200   1360x1020  1152x900

For 546x chips, the above table isn't quite accurate. While the virtual width may be any size, the screen pitch will be rounded up to the nearest value in the table below. Thus, each line on the screen will take more video memory than just what is displayed. To maximize video memory, then, choose the virtual desktop width from the table of pixel widths below:

>     8bpp:	640, 1024, 1280, 1664, 2048, 2560, 3328, 4096, 5120, 6656
>     16bpp:	320,  512,  640,  832, 1024, 1280, 1664, 2048, 2560, 3328
>     24bpp:	640, 1024, 1280, 1664, 2048, 2560, 3328, 4096, 5120, 6656
>     32bpp:	160,  256,  320,  416,  512,  640,  832, 1024, 1280, 1664

For other Cirrus chips, it's advisable to have a virtual width that is a multiple of 32 if acceleration is used. The horizontal monitor timings must be below 2048.

To run `XF86_SVGA` at a higher color depth, 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') (not on 5462)
    startx -- -bpp 24		8-8-8 RGB truecolor
    startx -- -bpp 32		8-8-8 XRGB truecolor (543X/46/6X only)

Information for Cirrus Chipset Users : Supported chipsets
Previous: Information for Cirrus Chipset Users
Next: Basic configuration