COMPUTER DATA CONVERSION CONTENTS
WEEK 9
CLASS: SS 2
SUBJECT: COMPUTER SCIENCE
TOPIC: COMPUTER DATA CONVERSION CONTENTS
- Definition – Register, Address, Bus
- Types of register
- Function of each register
- Differences between register and main memory
Sub-Topic 1: Definition
Data conversion is the conversion of computer data from one format to another. Throughout a computer environment, data is encoded in a variety of ways. For example, computer hardware is built on the basis of certain standards, which requires that data contains, for example, parity bit checks. Similarly, the operating system is predicated on certain standards for data and file handling. Data conversions may as simple as the conversion of a text file from onecharacter encoding system to another; or more complex, such as the conversion of office file formats, or the conversion of image and audio file formats.
There are many ways in which data is converted within the computer environment. This may be seamless, as in the case of upgrading to a newer version of a computer program.
REGISTER
These are temporary storage areas for instructions or data. They are not part of memory; rather they are special additional storage locations that offer the advantage of speed. Register work under the direction of the control unit to accept, hold and transfer instruction or data and perform arithmetic or logical comparisons at high speed.
Most operations are done on registers; the processor can’t directly perform arithmetic in memory for example. If you want to add 1 to a memory location, the processor will normally do this by loading the initial value from memory into a register, adding 1 to the register, and then saving the value back to memory.
MEMORY ADDRESS
This is an identifier for a memory location, at which a computer program or a hardware device can store data and later retrieve it. Each memory location, in both ROM and RAM, holds a binary number and only depends on the context of the instructions which retrieve and manipulate it.
BUS
The buses are media that connect the microprocessor (CPU) to each of the RAM, ROM, and input/output (I/0). Through the buses, information transfer takes place between the CPU and the I/O devices.
TYPES OF REGISTERS
Registers are normally measured by the number of bits they can hold, e.g “8-bit register” to “32-bit register”.
MDR- Memory Data Register
This is a register of a computer’s control unit that contains the data to be stored in the computer storage (e.g. RAM), or the data after a fetch from the computer storage. It acts like a buffer and holds anything that is copied from the memory ready for the processor to use it.
MDR is a two-way register. MDR is half of a minimal interface between a micro-program and computer storage, the other half is a memory address register.
CIR – Current Interrupt Register
This is part of the CPU’s control unit that stores the instruction currently being executed or decoded. This captures the value that is winning the interrupt arbitration. The CIR is updated at the beginning of an interrupt acknowledge (IACKN) us cycle or in response to an update CIR command. The contents remain in the CIR until another IACKN cycle or update command occurs. Modern processor can perform some of the operation out of order as decoding on several instructions is done in parallel.
Others are:
- User-accessible Register
- Data Register
- Address Register
- Conditional Register
- General Purpose Register (GPRs)
- Floating Point Register (FPRs)
- Constant Register
- Vector Register
- Special Purpose Registers
EVALUATION
- List and explain three types of register
- CIR, MDR stands for?
Sub-Topic 2: DIFFERENCES BETWEEN REGISTER AND MAIN MEMORY
Register:These are storage locations internal to the processor. CPU instructions operate on these value directly. On RISC (Reduced Instruction Set Computer) processors, all data must be moved into a register before it can be operated. On CISC (Complex Instruction Set Computer) (Intel) chips, there are a few operations that can load data from RAM, process it, and save the result back out, but the fastest operations work directly with registers.
Also there are registers that are set aside for certain tasks, these generally include a program counter stack,
and flags.
Each register also has a size that determines the maximum amount of data that can be processed at a time. The registers on Pentium chips, for example are 32 bits.
Finally, there are generally only a few registers available on a processor. Intel chip, for example, have 6 general purpose registers, and several specialized registers including a base register, stack register, flags register, program counter and some addressing registers.
Memory or RAM:Is located external to the CPU. Generally speaking, data has to be loaded into a CPU register from memory before the CPU can process it.
RAM is much slower than registers, there is a lot more RAM than registers, and generally memory can be addressed on byte boundaries, where register may not be able to access all the bytes in a register.
Summarily, registers are temporary storage in CPU while RAM holds the program instructions and the data the program requires.
EVALUATION
- Write short note on Register
- What is register?
General Evaluation
- Differentiate between the register and main
- What is a bus?
- What do you understand by memory address?
Reading Assignment
Read next week’s topic and summarize it.
WEEKEND ASSIGNMENT
- is much slower than registers. (a) Bus (b) RAM (c) register (d) None
- RISC stands for
(a) Rise in support Computer (b) Reduced instruction symbolic computer (c)
Reduced Instruction Set Computer
- MDR stands for
- CISC stands for
- are media that connect the microprocessor (CPU) to each of the RAM, ROM, and input/output (I/0). (a) Buses (b) RAM (c) register (d) None
ESSAY QUESTIONS
- Compare register and main memory
- What are the characteristics of a bus?
