Flashcards: Microprocessor Systems Architecture — 58 cards

What is computer science?

The science of processing information combining information with automation.

What distinguishes hardware from software in a computer system?

Hardware is the concrete part, software is program instructions in memory.

What is a microprocessor?

A complex integrated circuit that interprets and executes program instructions.

Who created the first microprocessor and when?

Intel in 1971.

What was the first microprocessor created by Intel?

The 4-bit 4004.

At what frequency did the Intel 4004 microprocessor operate?

At 108 kHz.

When did Texas Instruments produce the first integrated circuit?

In 1958.

When did the transistor first appear?

In 1947.

What values can a bit take in binary information?

0 or 1

How many bits make up a byte?

8 bits

What decimal number equals the binary number $(101)_2$?

5

How is the binary number $(101)_2$ calculated in decimal?

$1\times2^2+0\times2^1+1\times2^0$

What decimal number equals the hexadecimal number $(9A)_{16}$?

154

How is the hexadecimal number $(9A)_{16}$ calculated in decimal?

$9\times16^1+10\times16^0$

How many symbols does the hexadecimal system use?

Sixteen symbols

Which symbols are used in the hexadecimal system?

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F

What is the von Neumann model?

A universal machine architecture for programmed information processing.

Who proposed the von Neumann model and when?

John von Neumann in 1946.

What components does a basic von Neumann system contain?

A CPU, main memory, and input/output interfaces connected by buses.

What does the microprocessor do under the timing of a clock?

Interprets and executes instructions, reads or saves results, and communicates with exchange units.

By what three characteristics is a microprocessor defined?

Clock frequency, instruction rate, and data size it can process.

What is a bus in computer architecture?

A set of wires transmitting the same type of information between components.

What direction does the data bus transfer information?

It transfers information bidirectionally between the microprocessor and its environment.

How does the address bus select information in memory?

It selects information unidirectionally in an address space of up to $2^n$ locations.

What is the role of the control bus?

It synchronizes information flows on the data and address buses.

What does address decoding do in a computer system?

It assigns each peripheral an address zone and selects one component at a time.

What is a memory in semiconductor circuits?

A circuit that records, retains, and restores information.

How many memory locations can an n-bit address reference?

At most $2^n$ memory locations.

How many data words does each memory location contain?

One data word.

What are the steps in a memory read or write cycle?

Selecting address, choosing operation, selecting memory, reading or writing data.

Which inputs and outputs does a memory circuit have?

Address inputs, data inputs, data outputs, read/write control, and chip-select input.

What is memory capacity in computing?

The total number of bits stored in a memory.

How is memory capacity commonly expressed?

In bytes.

What does memory access time measure?

The interval between launching a read or write and data availability on the bus.

What characterizes random access memory?

It reaches any known address in an address-independent time.

How does sequential access differ from random access?

It requires searching through preceding information and has position-dependent access time.

What does volatility describe in memory?

Whether stored information is lost or altered when power fails.

What happens to information in volatile memory when power fails?

It loses the stored information.

How does non-volatile memory behave when power is lost?

It preserves the stored information.

What type of storage does RAM provide compared to ROM?

RAM provides temporary storage, ROM provides permanent storage.

How does SRAM store each bit differently from DRAM?

SRAM uses a bistable circuit with four to six transistors per bit.

How does DRAM store each bit?

DRAM stores each bit as an electrical charge in a capacitor.

Why must DRAM be refreshed regularly?

Leakage currents discharge its capacitor requiring refresh.

What must follow each destructive read in DRAM?

Each destructive read must be followed by a rewrite.

Which memory type offers greater density and lower cost per bit?

DRAM offers greater density and lower cost per bit.

For what purpose is faster SRAM typically used?

SRAM is used for small memories like caches and registers.

How does DDR-SDRAM differ from SDRAM in data transfer?

DDR-SDRAM transfers data on both rising and falling clock edges.

How is ROM programmed compared to PROM?

ROM is programmed by the manufacturer and cannot be modified by the user, while PROM can be programmed once by the user.

What is EPROM?

EPROM is a programmable ROM erasable by ultraviolet radiation and reprogrammable over a thousand times.

What distinguishes EEPROM from other ROM types?

EEPROM is electrically erasable and programmable in situ, erased word by word.

How does Flash NOR differ from Flash NAND in access and programming?

Flash NOR allows random access and byte-by-byte programming, Flash NAND uses sequential access and sector-based programming.

Why do NAND Flash cells allow higher integration density than NOR Flash cells?

Because NAND Flash cells are about 40% smaller than NOR Flash cells.

What are the main criteria for choosing a memory?

Capacity, speed, power consumption, and cost.

How does memory hierarchy balance performance and cost?

By placing frequently used data in small, fast memories and less-used data in larger, slower memories.

What is the order of memory types from processor outward in the hierarchy?

Registers, cache memory, main memory, backing memory, and mass storage.

How do capacity and access time change outward in the memory hierarchy?

Both capacity and access time generally increase.

What is cache memory?

A small, fast memory that speeds access to main memory by storing frequently used data.

What is mass storage?

A large-capacity peripheral memory for permanent storage or backup on magnetic or optical media.