COMPSCI 210

• Signed Integers 2^n values. Half of the integers are in range (1 to 2 ^(n-1)) - 1) and ther half to negative integers in range (-(2^(n-1) + 1 to -1) H
• Non-positional notation (unary) "Represent a number with a string of ones e.g. ""5"" is represented as ""11111"""
• Weighted Positional Notation Like decimal and binary numbers
• How many bits do unsigned integers represent? From 0 to (2^(n)) - 1
• Signed-Magnitude Leftmost bit represents the sign of the number, 0 = postive and 1 = negative
• What Is The Range Of Values That Can Be Represented For 2's Complement With N Bits -2(n-1) to 2(n-1) - 1
• How Many Group Of Bits Is Needed To Convert From Hex To Binary 4
• What Does ASCII Stand For? American Standard Code for Information Interchange
• How Many Charcters Can ASCII Represent? "28 = 256. However 1 it was used for checking ""errors"" so technically 2^7 = 128 characters"
• What Property Does The Decoder Have? Exactly one of its outputs is 1 and all the rest are 0s
• What Is A Decoder "Converts an n-bit input code to a m-bit output code such that n <= m <= 2n. Note that m can be less than 2n"
• General Definition Of A Mux "A mux has 2n data inputs, n select lines and one output"
• What Is The R-S Latch Used For? Store a bit of information
• What State Is It Called When R = S = 1 "The quiescent state as the output stays the same and the circuit ""remembers"" this data"
• What And How Does A Register Store Data A register stores a multi-bit value, uses a collection of D-latcjes controoled by a WE (write enable)
• What Are Examples Of Combinational Logic Circuits? Multiplexers and decoders
• Memory - What Is Address Space? What Is Addressiblity? Address Space - number of locationsAddressability - number of bits per location
• What Are The Two Kinds Of Ram? Static and dynamic
• What is Static Ram (SRAM)? Information is stored in latches. It is fast and maintains data without power and is commonly used for the computer's cache memory
• What Is Dynamic Ram (DRAM)? Info stored in electrical charges. Main memory. It is slow than SRAM but denser (more compact storage per data, uses less transistors to store each bit of data), decays and has to be preiodcally refreshed
• What Is The Range Of Bits That Can Be Represented By One's Complement? " −(2N−1−1) to 2N−1−1 "
• When Was The Von Neumann Architecture Introduced? In 1946 John Von Neumann introduced the architecture with the stored-program concept
• What Is The Basic Structure Of The Von Neumann Machine? "- Memory containing instructions and data- Processing unit for performing arithmetic and logical operations- Control unit for interpreting instructions- Input and output to iteract with the outside world"
• How Does Processing Unit Get Data To/From Memory? MAR (Memory Address Register) and MDR (Memory Data Register)
• How To LOAD A Location (A) "- Write the address (A) into the MAR- Send a ""read"" signal to the memory- Read the data from MDR"
• How To STORE A Value (X) To A Location (A) "- Write the data (X) to the MDR- Write the address (A) into the MAR- Send a ""write"" signal to the memory"
• Processing Unit - What Are The Functional Units? - ALU - Arithmetic and Logic Unit- LC-3 performs AND, ADD, NOT
• Processing Unit - Whar Are Registers? - Small, temp storage of data- Operands and results of funtional units- LC-3 has eight registers (R0 - R7) each 16 bits wide
• What Is The Control Unit? - Orchestrates execution of the program- IR contains the current instruction- Program Counter contrians the address of the next instruction to be execuuted
• What Does The Control Unit Do? - Reads an instruction from memory - the instruction's address is in the PC (Program Counter)- Interprets the instruction, generates signals which tell other components what to do. An instruction may take mnay mahcine cycles to complete
• What Is Instruction Set Architecture (ISA)? A computer's instructions and their formats
• What Are The First 2 Components Of The VNA + Explain Process  The control unit reads an instruction from memroy where the address of the instruction is in the PC. The control unit interperates this instruction anad genertaes sequence of control signals to other components to carry out the operation
• What Are The 6 Basic Phases Of Instruction Processing? Fetch instruction (from memory) -> decode instruction -> evaluate address -> fetch operands -> execute operation -> store result
• What does FETCH do? - Loads next instruction at address stored in the PC into MAR from memory into the IR. The data addressed by MAR is then fed into the MDR - Then the PC is incremented (PC += 1)
• What Is The Process Of The DECODE Phase? Identify the opcode and then based on the opcode instruction (e.g. LDR, ADD etc), idenitfy other operands from the remaining bits
• What Are Operands? Data/locations to be used for operation
• What Is The Evaluate Address Phase? "For instructions that require memory access, compute address used for access?"
• What Is The Fetch Operands Phase? Get the source operands needed to perform operation (.e.g. read data fromr register file (ADD))
• What Is The Execute Phase? Perform the operation using the source operands- Send operands to the ALU and send ADD signal- Do nothing (for loads and stores)
• What Does The Store Phase Do? Write results to destination (register or memory)