User's Manual

Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
R
189
12.3.5. BR04—Clip Rectangle X1 and X2
Memory Offset Address: 40010h
Default: None
Attributes: RO; DWord accessible
BR04 is loaded by either the SETUP_BLT or SETUP_MONO_PATTERN_SL_BLT instructions and is
used with PIXEL_BLT, SCANLINE_BLT, or TEXT_BLT instructions.
31 28 27 16
Reserved. Must be Zero Clip Rectangle X2 coordinate (right) [11:00]
15 12 11 0
Reserved. Must be Zero Clip Rectangle X1 coordinate (left) [11:00]
Bit Descriptions
31:28 Reserved. Must be Zero.
27:16 Clip Rectangle X2 Coordinate. These 12 bits specify the right most X coordinate which is written to
the destination. The comparison is inclusive with a less than or equal. The byte address of this
coordinate is:
scan line address + X2 * bytes/pixel.
15:12 Reserved. Must be Zero.
11:0 Clip Rectangle X1 Coordinate. These 12 bits specify the left most X coordinate which is written to
the destination. The comparison is inclusive with a greater than or equal. The byte address of this
coordinate is:
scan line address + X1 * bytes/pixel.