Instruction Set Architectures (2) Flashcards
What does memory store?
Data and Programs
How many bits make up a byte?
8 bits make up 1 byte
What is meant by word-addressable memory?
Each data word has a unique address, in MIPS a unique address for each 32-bit data word
What is meant by byte-addressable memory?
Each byte has a unique address, MIPS is byte-addressable
What is meant by Big-endian?
Most significant value in the sequence is first at the lowest storage address
What is meant by Little-endian?
The least significant value in the sequence is first
What are the two ways of accessing memory?
- Reading or loading
- Writing or storing
What 2 registers are necessary to access memory?
- Memory Address Register (MAR)
- Memory Data Register (MDR)
How is memory read?
- Load the MAR with the address
- Data is placed in MDR
How is memory written?
- Load the MAR with the address and the MDR with the data
- Activate Write Enable signal
What are 3 input devices?
- Keyboard
- Mouse
- Scanner
What are 3 output devices?
- Monitor
- Printer
- Speaker
What is the Control Unit?
Keeps track of the instruction being executed with an Instruction Register (IR), containing the instruction
What is the Program Counter?
Register containing the address of the next instruction to execute
What are the two key properties of the Von Neumann Model?
- Stored Program: stored in a linear memory array, and memory is unified
- Sequential instruction processing: one instruction processed at a time, program counter is advanced sequentially
What is meant by the Stack?
- Memory area used to save local variables
- It is a Last-In-First-Out (LIFO) queue
- The stack pointer ($sp) points to the top of the stack
