MICROPROCESSORS Flashcards
What is a microcomputer
a less powerful mini computer that contains a microprocessor as its central processor.
What are the advantages of microcomputers
can functionally replace thousands of random logic chips,
but occupies a much lesser space,
costs much lesser
and the number of device interconnections being fewer in it, is much more reliable.
What is a microprocessor?
an integrated circuit designed to function as the CPU of a microcomputer
Define the architecture of a microprocessor and draw a diagram depicting the same
organizational structure of μP(microprocessor), which determines how it operates, is known as its architecture.
See notes for pic
What is a word in the context of a microprocessor?
μC operates on a group of bits which are referred to as a word.
• The number of bits making-μP a word varies with the μP.
• Common word sizes are 4, 8, 12 and 16 bits (μPs with 32 bit-word have also of late entered the market).
What are bytes and nibbles
byte-8 bits
nibble- 4 bits
What are buses?
data highways that allow exchange of words between
the interconnecting blocks of the μP.
• A bus has a wire or line for each bit and thus allows exchange of all bits of a word in parallel.
*The width of a bus is the number of signal lines that constitute the bus.
What are the different types of buses?
Address bus - carries memory addresses from the processor to other components such as primary storage and input/output devices.
Data bus - carries the data between the processor and other components.
Control bus - carries control signals from the processor to other components.
What are internal registers used for in microprocessors?
temporary storage of data, instructions and addresses during execution of a program.
List the types of registers found in the Intel 8085 microprocessor
- Accumulator (Acc) or Result Register - This is an 8-bit register used in various arithmetic and logical operations.
- General Purpose Registers or Scratch Pad Memory - There are six general purpose 8-bit registers that can be used by the programmer for a variety of purposes.
- Instruction Register (IR) - This 8-bit register stores the next instruction to be executed.
- Program Counter (PC) - This is a 16-bit register which holds the address of the next instruction that has to be fetched from the main memory and loaded into the instruction register.
- Stack Pointer (SP) - This is also a 16-bit register and is used by the programmer to maintain a stack in the memory while using subroutines.
- Status Register or Condition Flags - A status register consisting of a few flip-flops, called as condition flags.
- Dedicated Registers - Several other registers are incorporated in the μP for its internal operation. They cannot be accessed by the programmer and hence do not concern much a μP user.
What is the function of the Instruction Decoder and Control Unit
• It decodes each instruction and under the supervision of a clock controls the external and internal units ensuring correct logical operation of the system.
Give examples of information stored in microprocessors
a. the data to be used for computation
b. instructions and
c. computational results.
What are the two classes of memory?
- Random Access Memory (RAM) or Read/Write Memory (RWM)
2. Read-Only Memory (ROM)
Discuss Bipolar v/s MOS Memories
- Basically there are two semiconductor technologies,
namely, bipolar and MOS unipolar.
• Mask ROMs and PROMs are available in both types whereas EAROMs and EPROMs are made with MOS technology only.
• In general, bipolar devices (including memories) are faster and have higher drive capabilities.
• On the other hand, MOS devices consume less space and power.
Describe a peripheral interface
When one or more I/O devices (peripherals) are to be connected to a μP, an interface network for each device, called peripheral interface, is required.
What are the functions of a peripheral interface?
- Buffering : Which is necessary to take care of incompatibility between the μP and the peripheral.
- Address Decoding : Which is required to select one of the several peripherals connected in the system.
- Command Decoding : Which is required for peripherals that perform actions other than data transfers.
- Timing and Control : All the above functions require timing and control.
What are the two main categories for data exchanges that occur between a peripheral device and the μC
- Programmed Data Transfer - A software routine residing in memory requests the peripheral device for data transfer to or from the μP.
- Direct Memory Access (DMA) Transfer or Cycle Stealing Transfer - the data transfer is controlled by the
peripheral device
Give examples of hardware(IC Chips ) that can be used to build a custom interface
multiplexer, and demultiplexers, line drivers and
receivers, level translators and buffers a stable and monostable multivibrators, latches, gates, shift registers, and so on.
What is a program and what is software
A sequence of instructions designed to perform a particular task in a computer is known as the program and a set of programs written for a computer-based system is called software for that system.
Examples of software tools
Assembler, Compiler, Editor, System Monitor
What does it mean to say that that the memory is 133MHz and the processor is 1.4 GHZ?
Saying a memory is 133Mhz means that the memory can be accessed at 133,000,000 cycles per second. The speed of the processor is 1, 400,000,000 cycles per second.
