Integrated Functions (Continued)
Table 4-28. Display Controller Register Summary (Continued)
GX_BASE+
Memory Offset
Default
Value
Type
Name/Function
DC_BUF_SIZE
8328h-832Bh
R/W
xxxxxxxxh
Display Controller Buffer Size: Specifies the number of bytes to transfer for a line of frame
buffer data and the size of the compressed line buffer. (The compressed line buffer will be
invalidated if it exceeds the CB_LINE_SIZE, bits [15:9].)
832Ch-832Fh
Timing Registers
8330h-8333h
--
Reserved
00000000h
xxxxxxxxh
R/W
DC_H_TIMING_1
Display Controller Horizontal and Total Timing: Horizontal active and total timing
information.
8334h-8337h
8338h-833Bh
R/W
R/W
DC_H_TIMING_2
xxxxxxxxh
xxxxxxxxh
Display Controller CRT Horizontal Blanking Timin: CRT horizontal blank timing
information.
DC_H_TIMING_3
Display Controller CRT Sync Timing: CRT horizontal sync timing information. Note, how-
ever, that this register should also be programmed appropriately for flat panel only display
since the horizontal sync transition determines when to advance the vertical counter.
833Ch-833Fh
8340h-8343h
R/W
R/W
DC_FP_H_TIMING
xxxxxxxxh
xxxxxxxxh
Display Controller Flat Panel Horizontal Sync Timing: Horizontal sync timing information for
an attached flat panel display.
DC_V_TIMING_1
Display Controller Vertical and Total Timing: Vertical active and total timing information.
The parameters pertain to both CRT and flat panel display.
8344h-8247h
8348h-834Bh
834Ch-834Fh
R/W
R/W
R/W
DC_V_TIMING_2
xxxxxxxxh
xxxxxxxxh
xxxxxxxxh
Display Controller CRT Vertical Blank Timing: Vertical blank timing information.
DC_V_TIMING_3
Display Controller CRT Vertical Sync Timing: CRT vertical sync timing information.
DC_FP_V_TIMING
Display Controller Flat Panel Vertical Sync Timing: Flat panel vertical sync timing
information.
Cursor and Line Compare Registers
8350h-8353h
R/W
DC_CURSOR_X
xxxxxxxxh
xxxxxxxxh
Display Controller Cursor X Position: X position information of the hardware cursor.
8354h-8357h
RO
DC_V_LINE_CNT
Display Controller Vertical Line Count: This read only register provides the current scanline
for the display. It is used by software to time update of the frame buffer to avoid tearing arti-
facts.
8358h-835Bh
835Ch-835Fh
R/W
R/W
DC_CURSOR_Y
xxxxxxxxh
xxxxxxxxh
Display Controller Cursor Y Position: Y position information of the hardware cursor.
DC_SS_LINE_CMP
Display Controller Split-Screen Line Compare: Contains the line count at which the lower
screen begins in a VGA split-screen mode.
8360h-8363h
8364h-8367h
8368h-836Bh
836Ch-836Fh
--
--
--
--
Reserved
Reserved
Reserved
Reserved
xxxxxxxxh
xxxxxxxxh
xxxxxxxxh
xxxxxxxxh
www.national.com
142
Revision 1.1
NSC [ National Semiconductor ]
