architectures non von neumann - rochester institute of...
Post on 09-May-2018
222 Views
Preview:
TRANSCRIPT
Non Von Neumann ArchitecturesBy Dylan Ayrey and Joshua Pueschel
The agenda● Review of the Von Neumann Model● What is the Harvard Architecture● What is the Modified Harvard Architecture● Examples/Current Uses● SHARC● MIMD
The Von Neumann Model● “Pure” von neumann model● Completed one after another● Limited by previous instruction
Von Neumann Bottleneck
● Wait for new instructions
● Idle time● “Hacky”
workarounds (caching, multi threading etc..)
Harvard Architecture: What is it?
● Von Neumann “alternative”
● Data memory and program instructions kept separate
● Parallel read/write from program instructions and data memory
○ Separate memory buses
Where did it come from?● Harvard Mark I
○ Started in 1937 by IBM○ Finished in 1944○ Used in war effort○ First program it ran created
by John Von Neumann to calculate nuclear bomb science
○ Paper punch tape
● Predates Von Neumann model (1945)
● Still used today
Modified Harvard Architecture● Common modifications
○ Shared memory/split cache● Most modern implementations are modified
○ Current ARM Architectures○ x86
Modern examples● ARM9/ARM11
○ Cellphones○ Raspberry pi○ Nintendo
● Digital Signal Processors
AMD Athlon 64 Cache Hierarchy
● Modified harvard architecture split L1 Cache
● Shared L2 cache
Cache Structure of ARM9 Processor
● Two distinct caching levels
● Shared common memory
SHARC Architecture● Extended cache for instruction reuse● Allows program bus to transfer data memory● DSP architecture
SHARC Architecture
Modified Von Neumann● DSP Example● Need multiple memory accesses in a single
instruction● Speed up the memory clock to be faster than
a single instruction cycle
Other Non Von Neumann● Analog Computers● Optical Computers● Quantum Computers● Cell Processors● DNA● Neural Networks● MIMD architecture
Non Von Neumann● Parallelism
○ Complex / low programmability● uPD7281D
○ image pipelined processor○ Could process different commands simultaneously
MIMD Architecture● Multiple Instruction stream, Multiple Data● Independent processors that operate on
separate data concurrently● Shared memory
MIMD Architecture Cont.
Design problems● Processor design● Physical organization● Interconnection structure● Inter-processor communication protocols● Memory hierarchy● Cache organization and coherency● Operating system design● Parallel programming languages● Application software techniques
top related