摘要:
Primitives are divided into span groups of 2N spans, and then processed in M×N blocks of pixels, with the pixel blocks preferably being as close to square as possible and therefore optimized for small spans and texture mapping. Each span group is rendered block-by-block in a serpentine manner from an initial or entry block, first in a direction away from the long edge of the primitive and then in a direction towards the long edge. The interpolators include a one-deep stack onto which pixel and texel information for the initial or entry block are pushed before rendering any other blocks within the span group. Blocks or pairs of blocks within different span subgroups of the span group are then alternately rendered, such that rendering zig-zags between the span subgroups as it proceeds to the end of the span group. Once the first end of a span group is reached, the values for the initial or entry block are popped from the stack and rendering resumes from the initial or entry block in the opposite direction, but in the same serpentine or zig-zag manner, until the other end of the span group is reached. The next span group, if any, is rendered starting with a block adjacent to the last block rendered in the previous span group. Memory bandwidth utilization between the pixel and texel cache and the frame buffer is thus improved, together with texel reuse during texture mapping, to reduce the total number of pixel and texel fetches required to render the primitive.
摘要:
A method, apparatus, and computer implemented instructions for generating antialiased lines for display in a data processing system. Graphics data is received for display, wherein the graphics data includes primitives defining lines. A gamma correction is applied to the graphics data on a per primitive basis to form antialiased lines. The antialiased lines are displayed.
摘要:
Graphics information is efficiently transferred from a host computer to a graphics subsystem in which rendering and pixel data is generated by the host system. A masked span operation provides an assist for 3D rendering performed by the system processor of the host and other system resources. Storage of depth, alpha, stencil, and other pixel data is in system memory including one or more ancillary graphics buffers. The main processor of the host system generates pixel data associated with an image. This data is checked against the buffers. As a result of such checking, a mask is generated by the host system. The mask is transferred in burst mode across the host-graphic subsystem PCI bus to the graphics subsystem in combination with span width, and in the case of interpolated color, color base and color increment data, and X,Y coordinate of the first pixel. In the graphics subsystem the mask is employed with the other data to load the frame buffer with the portion of pixel data defined by the mask.
摘要:
A processor-cache operational scheme and topology within a multi-processor data processing system having a shared lower level cache (or memory) by which the number of coherency busses is reduced and more efficient snoop resolution and coherency operations with the processor caches are provided. A copy of the internal (L1) cache directory is provided within the lower level (L2) cache or memory. The snoop operations and coherency maintenance operations of the L1 directory are completed by comparing the snoop addresses with the address tags of the copy of the L1 directory in the L2 cache. Updates to the coherency states of the copy of the L1 directory are mirrored in the L1 directory and L1 cache. This eliminates the need for the individual coherency buses of each processor that is coupled to the L2 cache and speeds up coherency operations because the snoops do not have to be transmitted to the L1 caches.
摘要:
An apparatus which uses channel counters in combination with channel count read instructions as a means of providing information that data in a given channel is valid or has not been previously read. The counter may also, in the situation of the channel being defined as blocking, be used to prevent the unintentional overwriting of data in a register used by the channel or, alternatively, prevent further communications with the device assigned to that channel when a given count occurs. Intelligent external devices may also use channel count read instructions sent to the counting mechanism for reading from and writing to the channel.
摘要:
The present invention provides for authenticating code and/or data and providing a protected environment for execution. The present invention provides for dynamically partitioning and un-partitioning a local store for the authentication of code or data. The local store is partitioned into an isolated and non-isolated section. Code or data is loaded into the isolated section. The code or data is authenticated in the isolated section of the local store. After authentication, the code is executed. After execution, the memory within the isolated region of the attached processor unit is erased, and the attached processor unit de-partitions the isolated section within the local store.
摘要:
Disclosed is an apparatus which operates to substantially evenly distribute commands and/or data packets issued from a managed program or other entity over a given time period. The even distribution of these commands or data packets minimizes congestion in critical resources such as memory, I/O devices and/or the bus for transferring the data between source and destination. Any unmanaged commands or data packets are treated as in conventional technology.
摘要:
A mechanism provides for sending an envelope and replying to an envelope. A transmitter is configured to send an envelope. A receiver is coupled to the transmitter, wherein the receiver is configured to receive the envelope and generate a reply envelope. A send buffer is coupled to the transmitter. A receive buffer is coupled to the receiver. A retry timer is coupled to the transmitter, wherein the retry timer is configured to reset upon the receipt of a reply envelope correlated to the transmit envelope. The transmitter is configured to retransmit an envelope if the transmitter does not receive a corresponding reply envelope within a selected time period as determined by the retry timer. This leads to a decrease in the total number of envelopes, transmitted from both the transmitter and the receiver.
摘要:
Methods and apparatus provide for interconnecting one or more multiprocessors and one or more external devices through one or more configurable interface circuits, which are adapted for operation in: (i) a first mode to provide a coherent symmetric interface; or (ii) a second mode to provide a non-coherent interface.
摘要:
The present invention provides a method and apparatus for creating memory barriers in a Direct Memory Access (DMA) device. A memory barrier command is received and a memory command is received. The memory command is executed based on the memory barrier command. A bus operation is initiated based on the memory barrier command. A bus operation acknowledgment is received based on the bus operation. The memory barrier command is executed based on the bus operation acknowledgment. In a particular aspect, memory barrier commands are direct memory access sync (dmasync) and direct memory access enforce in-order execution of input/output (dmaeieio) commands.