摘要:
A memory array management unit suitable for use in a computer graphics system is described. The unit is especially designed to facilitate the storage of tiles of graphics data. Alignment detection between the tiles and memory block boundaries is provided for, with misalignments resulting in the automatic decimation to produce sub-tiles and generation of multiple memory write sequences.
摘要:
An external cache management unit for use with 3D-RAM and suitable for use in a computer graphics system is described. The unit maintains and tracks the status of level one cache memory in the 3D-RAM. The unit identifies dirty blocks of cache memory and prioritizes block cleansing based on a least used algorithm. Periodic block cleansing during empty memory cycles is provided for, and may also be prompted on demand.
摘要:
A data queue optimized for receiving loosely packed graphics data and suitable for use in a computer graphics system is described. The data queue operates on first-in-first-out principals, and has a variable width input and output. The variable width on the input side facilitates the reception and storage of loosely packed data. The variable width output allows for the single-cycle output of multi-word data. Packing of the data occurs on the write-side of the FIFO structure.
摘要:
A rendering unit positions a supertile so that it intersects a primitive. The rendering unit repeatedly walks over bins of the supertile, applying a layer of texture to the bins of the supertile in each iteration of said repeated walking. The rendering unit advances to the next texture layer after having applied the current texture layer to each candidate bin of the supertile. The results of each texture layer application to the bins may be stored in a texture accumulation buffer. The size of the supertile corresponds to the size of the texture accumulation buffer. After applying a last layer of texture to the bins of the supertile, the supertile may be advanced to a new position. The rendering unit traverses the primitive with the supertile so that the union of areas visited by the supertile covers the primitive.
摘要:
A frame buffer memory device controller that schedules and dispatches operations to frame buffer memory devices is disclosed. The frame buffer memory device controller schedules and dispatches cache control operations to reduce timing overheads caused by cache prefetch operations, and operations to write back dirty cache lines and clear cache lines in the frame buffer memory devices. The frame buffer memory device controller also schedules and dispatches control operations to reduce timing overheads caused by video refresh operations from the frame buffer memory devices video output ports.
摘要:
A graphics system applies multiple layers of texture information to triangles. The graphics system includes a hardware accelerator, a frame buffer and a video output processor. The hardware accelerator receives vertices of a triangle, identifies fragments of a sampling space which intersect the triangle, and applies the multiple layers of texture to the intersecting fragments. The multiple layers of textures may be stored in a texture memory external to the hardware accelerator. The hardware accelerator switches to a next texture layer after applying the textures of a current layer to all the fragments of the triangle. The hardware accelerator includes (or couples to) a texture accumulation buffer which stores color values associated with the triangle fragments between the application of successive texture layers. The frame buffer stores the samples and pixels generated from the samples by filtration. The video output processor transforms the pixels into a video signal.
摘要:
A system and method for rasterizing and rendering graphics data is disclosed. Vertices may be grouped to form primitives such as triangles, which are rasterized using two-dimensional arrays of samples bins. Individual samples may be selected from the bins according to different criteria such as memory bank allocation to improve utilization of the system's rendering pipeline. Since the arrays may have more bins than the number of evaluation units in the rendering pipeline, the samples from the bins may be stored to FIFO memories to allow invalid or empty samples (those outside the primitive being rendered) to be removed. The samples may then be filtered to form pixels that are displayable to form an image on a display device.
摘要:
An external cache management unit for use with a 3D-RAM frame buffer and suitable for use in a computer graphics system is described. The unit may reduce power consumption within the 3D-RAM by performing partial block write-back according to status information stored in an array of dirty tag bits. Periodic level one cache block cleansing is provided for during empty memory cycles.
摘要:
A graphics system includes a frame buffer, a write address generator, and a pixel buffer. A burst of pixels received from the frame buffer may not be in display order. In one embodiment, a write address generator calculates a write address for each pixel in the burst of pixels output from the frame buffer. The write address corresponds to a relative display order within the burst for each respective pixel. Each pixel in the burst is stored to its write address in the pixel buffer. This way, the pixels in the burst are stored in display order within the pixel buffer.
摘要:
An external cache management unit for use with a 3D-RAM frame buffer and suitable for use in a computer graphics system is described. The unit may reduce power consumption within the 3D-RAM by performing partial block write-back according to status information stored in an array of dirty tag bits. Periodic level one cache block cleansing is provided for during empty memory cycles.