P.95
Bit 0-7
Bit 8-14
Bit 15
These bits would use to define the auxiliary color of hardware cursor for 24 bit color mode.
Reserved
This bit is used to select Hardware Cursor display color mode . A logical 0 indicates Topro VGA is
operated in two color mode . A logical 1 forces Topro VGA is operated in three color mode by using
cursor Auxiliary color to replace inversion destination data color.
GAREG Hex 2B : Graphics Command FIFO Status Register
This is a read/write register.
Default value after hardware reset is Hex 00,00.
Default port address AFC4.
PCI port address low AC.
D0
D1
D2
D3
D4
D5-7
D8-15
(*: Write access operation will reset graphic engine)
Graphics command access status
Host memory from Display memory write status
Host memory to Display memory read status
Command FIFO empty status
Command FIFO full status
Video line buffer valid status
Command FIFO valid status
Bit 0
This bit reflects the access status of Graphics commands . A logical 1 indicates Topro VGA is excuting
the Graphics command in busy ststus now . A logical 0 indicates Topro VGA has excuted the Graphics
command.
This bit reflects the write access status of Host memory to Display memory . A logical 1 indicates
Topro VGA is busy now .
This bit reflects the read access status of Host memory from Display memory . A logical 1 indicates
Topro VGA is busy now .
This bit reflects the command FIFO empty status . A logical 0 indicates the command FIFO is empty
now . A logical 1 indicates the command FIFO isn’t empty .
This bit reflects the command FIFO full status . A logical 0 indicates the command FIFO isn’t full . A
logical 1 indicates the command FIFO is full now .
These bits reflects the video line buffer vaild status as following description .
Bit-7
Bit-6
Bit-5
Status description
0
0
0
Video line buffer empty blocks < 4 (32-bits data/1 block)
0
0
1
Video line buffer empty blocks >= 4
0
1
1
Video line buffer empty blocks >= 8
1
1
1
Video line buffer empty blocks >= 16
These bits reflects the command FIFO vaild status as following description .
Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit 8
Status description
1 1 1 1 1 1 1 1
0 empty FIFO is available (Full)
0 1 1 1 1 1 1 1
1 empty FIFO is available
0 0 1 1 1 1 1 1
2 empty FIFO is available
0 0 0 1 1 1 1 1
3 empty FIFO is available
0 0 0 0 1 1 1 1
4 empty FIFO is available
0 0 0 0 0 1 1 1
5 empty FIFO is available
0 0 0 0 0 0 1 1
6 empty FIFO is available
0 0 0 0 0 0 0 1
7 empty FIFO is available
0 0 0 0 0 0 0 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5-7
Bit 8-15
8 empty FIFO is available (Empty)