Intel 815 manual Memory Buffers for GC’s Instruction Interface, Gtt

Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0

R

Figure 8. GTT Mapping

System Memory

4 GB 31 0

Base + 64 MB

Virtual

Graphics

Memory

Base

TOM

4KB

4KB

Graphics		Graphics Engine
Translation Table
		Address Space
(GTT)
31	0 64 KB	31	0 64 MB
Base + 32 MB
			0
	0 KB
		Optional Display
			Cache
GTT Maps 4KB blocks of Virtual
Graphics Memory to 4 KB pages in
System Memory	GTT Maps 4KB blocks of
	Virtual Graphics Memory
	to 4 KB pages in Display
	Cache

gtt.vsd

3.4.2.Memory Buffers for GC’s Instruction Interface

The GC provides two Ring Buffer (RB) mechanisms through which instructions can be passed to the GMCH’s Instruction Parser. In addition, the GC provides for the execution of instruction sequences external to the ring buffers. These sequences are called "batch buffers", and are initiated through the use of GFXCMDPARSER_BATCH_BUFFER instructions that specify the starting address and length of the batch buffers. For detailed information on these buffers, refer to the Programming Interface Chapter.

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