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<A HREF="cirrus.html"><EM> Information for Cirrus Chipset Users</EM></A>
 <b>:</b> <EM>Supported chipsets </EM><BR>
<b>Previous:</b> <A HREF="cirrus.html"><EM> Information for Cirrus Chipset Users</EM></A><BR>
<b>Next:</b> <A HREF="cirrus2.html"><EM>Basic configuration </EM></A>


<HR NOSHADE>
  <H2><A NAME="1"></A>1. Supported chipsets </H2>

<p>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:
<dl>
<dt><b>CL-GD5420</b><dd><p>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 <em>not</em> support 1024x768 non-interlaced in 256 colors.</p>
<dt><b>CL-GD5422</b><dd><p>Enhanced version of the 5420 (32-bit internal memory
interface). Maximum dot clock is 80 MHz.</p>
<dt><b>CL-GD6205/6215/6225/6235</b><dd><p>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 "<code>noaccel</code>" option.</p>
<dt><b>CL-GD6420/6440</b><dd><p>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
"<code>cl6420</code>" and <code>"cl6440"</code>.  This driver is discussed
in detail in section 
<A HREF="cirrus6.html#cl64xx">The cl64xx Driver</A>.</p>
<dt><b>CL-GD5424</b><dd><p>Basically VLB version of the 5422, but resembles the
5426 in some respects.</p>
<dt><b>CL-GD5426</b><dd><p>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.</p>
<dt><b>CL-GD5428</b><dd><p>Enhanced version of the 5426.</p>
<dt><b>CL-GD5429</b><dd><p>Enhanced version of the 5428; officially supports higher
MCLK and has memory-mapped I/O.</p>
<dt><b>CL-GD5430</b><dd><p>Similar to 5429, but with 543x core (32-bit host interface).
Does not have 64-bit memory mode.</p>
<dt><b>CL-GD5434</b><dd><p>`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).</p>
<dt><b>CL-GD5436</b><dd><p>Highly optimized 5434.</p>
<dt><b>CL-GD5440</b><dd><p>Similar to the CL-GD5430, and detected as such.</p>
<dt><b>CL-GD5446</b><dd><p>Another member of the Alpine family of 2D accelerators; similar
to the CL-GD5436.</p>
<dt><b>CL-GD5480</b><dd><p>Newer Alpine family chip that support synchronous graphics RAM
(SGRAM).</p>
<dt><b>CL-GD5462, CL-GD5464 and CL-GD5465</b><dd><p>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.</p>
<dt><b>CL-GD7541/7542/7543/7548</b><dd><p>Laptop chipsets more or less compatible with the 5428/3x.
While has it been tested on some configurations, not all
configuration may work correctly.</p>
<dt><b>CL-GD7555</b><dd><p>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.</p>
</dl>
</p>
<p>Here's a list of maximum dot clocks for each supported depth:</p>
<p>
<blockquote>
<pre>
                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.
</pre>
</blockquote>
</p>
<p>Rough virtual/physical screen resolution limits for different amounts of
video memory:
<blockquote>
<pre>
            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
</pre>
</blockquote>

For 546x chips, the above table isn't quite accurate.  While the virtual 
width may be any size, the screen <i>pitch</i> 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:
<blockquote>
<pre>
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
</pre>
</blockquote>
</p>
<p>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.</p>
<p>To run <code>XF86_SVGA</code> at a higher color depth, pass options to the
X server as follows:
<pre>
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)
</pre>
</p>


 <HR NOSHADE>
<A HREF="cirrus.html"><EM> Information for Cirrus Chipset Users</EM></A>
 <b>:</b> <EM>Supported chipsets </EM><BR>
<b>Previous:</b> <A HREF="cirrus.html"><EM> Information for Cirrus Chipset Users</EM></A><BR>
<b>Next:</b> <A HREF="cirrus2.html"><EM>Basic configuration </EM></A>



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