SCC131: Digital Systems - Topic 7: Building Memory

Flashcards reviewing key concepts related to building memory in digital systems, including memory types, organization, logic circuits, and bus architecture.

What are the components of the von Neumann architecture?

Arithmetic/Logic Unit, Control Unit, Main memory (Instructions and Data), Input, Output

What is the primary function of memory?

Stores bits

What are the two types of volatile memory?

Dynamic memory (main memory) and Static memory (registers and caches)

What are the characteristics of dynamic memory?

Slower than static memory, but relatively cheap; used for main memory.

What are the characteristics of static memory?

Fast but relatively expensive; used for registers and caches.

List the levels of the memory hierarchy.

Tape and optical media, Magnetic disks, Main Memory (dynamic memory), Caches (static memory), Registers (static memory)

How is main memory organized abstractly?

Each location has an address for identification.

What is the function of an address decoder?

Maps from a linear address to a specific location in a specific memory chip

What is Big-endian byte ordering?

The location (byte) with the lowest memory address holds the most-significant-byte (MSByte)

What is Little-endian byte ordering?

The location (byte) with the lowest memory address holds the least-significant-byte (LSByte)

What is the defining feature of combinatorial logic?

Outputs are purely a function of its inputs.

What is the defining feature of sequential logic?

Outputs are a function of its inputs and of its current outputs; involves feedback.

How does an S-R flip-flop work?

A high pulse on S always takes us to the Q=1 state (set); A high pulse on R always takes us to the Q=0 state (reset).

What are the limitations of the S-R flip-flop?

Distinct SET and RESET inputs and no way of telling the flip-flop exactly when it should store input data.

What is the purpose of a Clocked D-type flip-flop?

To latch a data value into a flip-flop; also provides output enable (OE).

How does a master-slave flip-flop work?

Registers data when the latch signal is high, but blocks master->slave transfer until the master-side latch goes low.

What is the role of buses in computer architecture?

Connects the ALU, the control unit, memory chips, and I/O devices.

What are the two types of Buses?

Address bus and Data bus