Intel 815 manual 12.3.10. BR09-Destination Address and Destination Y1 Address

Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0

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12.3.10. BR09—Destination Address and Destination Y1 Address

Memory Offset Address:						40024h
Default:						None
Attributes:						RO; DWord accessible
31				26	25	0
		Reserved. Must				Destination and Destination Y1 and Y Address Bits [25:0]
		be Zero
		Bit				Descriptions
	31:26			Reserved. Must be Zero.
	25:0			Destination and Destination Y1 and Y Address Bits. These 26 bits specify the starting pixel
				address of the destination data. This register is also the working destination address register and
				changes as the BLT Engine performs the accesses.
				Used as the scan line address (Destination Y Address & Destination Y1 Address) for BLT instructions:
				PIXEL_BLT, SCANLINE_BLT, and TEXT_BLT. In this case the address points to the first pixel in a
				scan line and is compared with the ClipRect Y1 & Y2 address registers to determine whether the scan
				line should be written or not. The Destination Y1 address is the top scan line to be written for text.
				This register is always the last register written for a BLT drawing instruction. Writing BR09 starts the
				BLT engine execution.
				Note:
				Some instructions affect only one scan line (requiring only one coordinate); other instructions affect
				multiple scan lines and need both coordinates.
	NOTES:		This is a working register. If BR09 is read while the BLT engine is busy, the contents are unpredictable.
12.3.11. BR10—Destination Y2 Address
Memory Offset Address:						40028h
Default:						None
Attributes:						RO; DWord accessible
31				26	25	0
		Reserved. Must				Destination Y2 Address Bits [25:0]
		be Zero
		Bit				Descriptions
	31:26			Reserved. Must be Zero. The maximum GC graphics address is 64 MBs. Debug implementation
				specific = bmtdpix[5:0]
	25:0			Destination Y2 Address. Used as the scan line address (Destination Y2 Address) for BLT instruction:
				TEXT_BLT. The address points to the first pixel in a scan line and is compared with the ClipRect Y1 &
				Y2 address registers to determine whether the scan line should be written or not. The Destination Y2
				address is the bottom scan line to be written for text.

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