Справочник Пользователя для AMD LX 900@1.5W
AMD Geode™ LX Processors Data Book
281
Display Controller
33234H
6.5.1
GUI Functional Overview
6.5.1.1
Display Mode Support
The display modes listed in Table 6-32 are supported by
the GUI block. 32- and 24-bpp display support is provided
across all resolutions. The Dot Clock source (DOTCLK) is
provided by a PLL. Available memory bandwidth deter-
mines the resolutions and color depths that will function
without display tearing. Memory controller configuration,
GLIU frequency, and other demands on the memory con-
troller set the available bandwidth. The GLIU frequency
determines the memory controller frequency. Other
demands on the memory controller such as the CPU and
bus masters affect on available bandwidth are difficult to
predict. Use of the video overlay feature additionally
decreases the bandwidth available for screen refresh.
the GUI block. 32- and 24-bpp display support is provided
across all resolutions. The Dot Clock source (DOTCLK) is
provided by a PLL. Available memory bandwidth deter-
mines the resolutions and color depths that will function
without display tearing. Memory controller configuration,
GLIU frequency, and other demands on the memory con-
troller set the available bandwidth. The GLIU frequency
determines the memory controller frequency. Other
demands on the memory controller such as the CPU and
bus masters affect on available bandwidth are difficult to
predict. Use of the video overlay feature additionally
decreases the bandwidth available for screen refresh.
The Minimum GLIU Frequency criteria listed in Table 6-32
must be met for quality operation of the display. This fre-
quency provides sufficient memory bandwidth for the mem-
ory controller to maintain reliable display refresh under all
operating conditions, including the video overlay. As a gen-
eral rule, Table 6-32 indicates what the minimum relation-
ship of DOTCLK to GLIU frequency should be at the
various color depths.
must be met for quality operation of the display. This fre-
quency provides sufficient memory bandwidth for the mem-
ory controller to maintain reliable display refresh under all
operating conditions, including the video overlay. As a gen-
eral rule, Table 6-32 indicates what the minimum relation-
ship of DOTCLK to GLIU frequency should be at the
various color depths.
Bandwidth requirements for the VGA engine are not listed
in this table. Most graphics modes require the same band-
width as comparable 8-bpp display modes listed in Table 6-
32. Text modes generally require higher bandwidth. Sup-
ported text modes require a GLIU clock frequency of 100
MHz or more to obtain the necessary memory bandwidth.
in this table. Most graphics modes require the same band-
width as comparable 8-bpp display modes listed in Table 6-
32. Text modes generally require higher bandwidth. Sup-
ported text modes require a GLIU clock frequency of 100
MHz or more to obtain the necessary memory bandwidth.
Table 6-32. Display Modes
Resolution
Color Depth (bpp)
Refresh Rate (Hz)
Dot Clock (MHz)
Min. GLIU Frequency (MHz)
640 x 480
8, 16, or 24/32
60
25.175
75
8, 16, or 24/32
70
28.560
75
8, 16, or 24/32
72
31.500
75
8, 16, or 24/32
75
31.500
75
8, 16, or 24/32
85
36.000
75
8, 16, or 24/32
90
37.889
400
8, 16, or 24/32
100
43.163
400
800 x 600
8, 16, or 24/32
60
40.000
75
8, 16, or 24/32
70
45.720
75
8, 16, or 24/32
72
49.500
75
8, 16, or 24/32
75
49.500
75
8, 16, or 24/32
85
56.250
75
8, 16, or 24/32
90
60.065
400
8, 16, or 24/32
100
68.179
400
1024 x 768
8, 16 or 24/32
60
65.000
75
8, 16, or 24/32
70
75.000
100
8, 16, or 24/32
72
78.750
100
8, 16, or 24/32
75
78.750
100
8, 16, or 24/32
85
94.500
100
8, 16, or 24/32
90
100.187
400
8, 16, or 24/32
100
113.310
400
1152x864
8, 16, or 24/32
60
81.600
100
8, 16, or 24/32
70
97.520
100
8, 16, or 24/32
72
101.420
200
8, 16, or 24/32
75
108.000
200
8, 16, or 24/32
85
119.650
200
8, 16, or 24/32
90
129.600
400
8, 16, or 24/32
100
144.000
400