With the advent of the Multimedia Age, the system requirements of programs have increased dramatically.  The complexities of these applications require that processors be powerful, yet flexible enough to accommodate various classes of applications efficiently.  Recently, various reconfigurable processors have been considered for satisfying these requirements. Reconfigurable computing represents a median between general purpose processors, which are capable of running different applications at the cost of increased execution time, as well as for Application-Specific Integrated Circuits (ASICs), which are processors only suitable for running certain types of applications but with much faster implementations.  The software programmer or the compiler of a reconfigurable processor should be capable of recognizing the configuration that is best suited for the program (or portion of) in question and ensuring that the processor is set to that configuration.

Traditional reconfigurable processors are statically reconfigurable, which means that the processor is configured at the start of program execution and remains unchanged for the duration of the program.  In order to reconfigure a statically reconfigurable processor, program execution would have to be halted while the reconfiguration is in progress, slowing down the execution of the program.  Dynamically reconfigurable processors, on the other hand, allow reconfiguration and execution to proceed at the same time.

The MorphoSys project proposes to design a unique dynamically reconfigurable computer architecture geared toward increasing performance of image processing applications.   The main components of the architecture (Figures 1 and 2) are the Tiny Reduced Instruction Set Computer (RISC) processor, Reconfigurable Cell (RC) Array, Context Memory, Frame Buffer (FB), Direct Memory Access (DMA) Controller, and main memory (i.e. DRAM, SRAM or RAMBUS).

Figure1-2L1.gif (9839 bytes)
Figure 1
The MorphoSys top-level block diagram




Figure2-2R1.gif (14338 bytes)
Figure 2
MorphoSys system interface

Several other components (not shown) complete the architecture: secondary storage (i.e. hard drive) and the external interface of the architecture (i.e. to the input and output ports).  Tiny RISC is a general purpose processor that handles all instructions not related specifically to image processing.   The RC Array is the dynamically reconfigurable co-processor that handles most of the image processing for MorphoSys.  The Context Memory stores configurations (called contexts) for the RC Array; the FB and DMA Controller act as the interface between the RC Array and the other components of MorphoSys.

At the time of this writing, the Tiny RISC processor, DMA Controller, and FB have been modeled in behavioral VHDL code; the VLSI design stage of these components has begun.   The VLSI design of the RC Array is complete.

Instruction set of the MorphoSys Architecture

The current MorphoSys instruction set consists of 44 Tiny RISC instructions (including newly-added Branch If Greater Than, Branch If Less Than, and Branch If Equal To) and 12 instructions for the operation of the RC Array, FB and DMA Controller.

Components of the MorphoSys Architecture

Frame Buffer:
The FB is a fast memory buffer used to store portions of frames of data (in image processing applications, each image is called a frame).  It is the buffer between the DMA Controller and RC Array. The DMA Controller has a 64-bit data bus connection to the FB.  The same bus is used for reading and writing data to and from the FB, and therefore the DMA Controller may not read and write at same time.  The RC Array has two 64-bit

back.gif (287 bytes) back.gif (221 bytes)


Page 2


U-Tee Cheah - The MorphoSys Project: Dynamically Configurable... [1] [2] [3] [4] [5] [6] [7]