Parallelism, Memory, Byte Ordering, Error Correcting

PARALLELISM

Instruction Level

• SuperScalar

Processor Level

• MultiProcessor
• CPUs share memory
• MultiComputers
• CPUs have own local memories

MEMORY

• Binary Coded Decimal (BCD) vs. Binary
• BCD translates each digit to binary individually
• Binary translates entire number  
• (more efficient - can express larger number than BCD with same # bits)

MEMORY ADDRESSES

• Memory - made up of cells (locations) that store information
• n Cells have addresses [0  --  n-1]
• Length of address depends on # of directly addressable cells in memory
• (independent of bits/cell)

BYTE ORDERING

• Big Endian (Most Significant cell gets index '0')
• Little Endian (Least gets '0')
• Jonathan Swift's Gulliver's Travels

ERROR CORRECTING CODE

• Codeword = m (data bits) + r (check bits) = n total bits
• ....
• ....
• Parity