BIOS, Processor & Motherboard

1. Imranul Hasan
Greenwich University, UK
BIOS, Processor & Motherboard

2. 21/04/2018
Booting Process
Booting Process
• When a computer is switched ON, the system performs
some important routine (tasks) taking a few seconds.
• Within that routine, the system completes a number of steps
to load the operating system from storage to the computer’s
memory (RAM).
• The process of checking and loading into computer’s
memory is called booting.

3. 21/04/2018
Booting Process
Steps are:
• BIOS loaded to the RAM.
• Performs Power on Self Test (POST) to check all the hardware connected
to the computer. POST, a diagnostic testing sequence run by a
computer’s BIOS as the computer’s power is initially turned on. The
POST will determine if the computer’s RAM, disk drives, peripheral
devices and other hardware components are properly working. If the
diagnostic determines that everything is in working order, the
computer will continue to boot.
• POST: checks for hardware errors.
• POST: detects address conflicts.
• Boot record is loaded to the memory. (Boot record contains instructions for
loading OS into RAM.)
• Loading the operating system.

4. BIOS

5. BIOS
 BIOS Acronym for Basic Input/Output System, the
built-in software that determines what a computer
can do without accessing programs from a disk.
 On PCs, the BIOS contains all the code required to
control the keyboard, display screen, disk drives,
serial communications, and a number of
miscellaneous functions.
 The BIOS is typically placed in a ROM chip that
comes with the computer (it is often called a ROM
BIOS). This ensures that the BIOS will always be
available and will not be damaged by disk failures. It
also makes it possible for a computer to boot itself.

6. BIOS
 Because RAM is faster than ROM, though,
many computer manufacturers design
systems so that the BIOS is copied from
ROM to RAM each time the computer is
booted. This is known as shadowing.
 Many modern PCs have a flash BIOS, which
means that the BIOS has been recorded on a
flash memory chip, which can be updated if
necessary.

7. BIOS Chip

8. BIOS Program

9. Boot sequence
 The order of drives that a system’s BIOS follows
when looking for the operating system (OS) to boot
after the computer has performed POST. For
example, the BIOS may be instructed to first look to
drive C (i.e., the hard disk) for the OS and then drive
A (i.e., the floppy disk). If the OS is stored in drive C
then the BIOS need look no further; however, if the
BIOS does not find the OS in drive C then it will next
look to drive A, and so on depending on the
configuration of the boot sequence.
 Users can change the order of the boot sequence
through the CMOS setup.

10. Motherboard

11. Motherboard
 The main circuit board of a microcomputer. The
motherboard contains the connectors for attaching
additional boards. Typically, the motherboard
contains the
 CPU
 BIOS
 Memory
 mass storage interfaces
 serial and parallel ports
 expansion slots and
 all the controllers required to control standard peripheral
devices, such as the display screen, keyboard, and disk
drive.

12. Some chipset suppliers and
models
 There are several
suppliers of chip sets for
the motherboard:
 Intel
 SIS
 Opti
 Via
 ALi
CPU
Chipset
RAM
PCI
EIDE
ROM BIOS, RTC
Keyboard
PS/2, IrDA
COM, LPT

15. Motherboard (Cont…….)

21. Processor

22. Fig. Basic Organization of a Computer System
Control Unit
Output Unit Result
Input UnitData
ALU
Memory Unit Data
Control Signal
Basic Computer Architecture

23. Central Processing Unit
 The CPU is the brain of any computer system.
 The control unit and the arithmetic logic unit of a
computer system are jointly known as the central
processing unit (CPU).
 Typically it has an arithmetic and logic unit (ALU),
control unit and number of registers that provide
temporary storage.
 A microprocessor generally requires some
additional circuitry to function as a complete
CPU.

24. Arithmetic and Logic Unit
 The arithmetic and logic unit (ALU) of a computer
system is the place where the actual execution of the
instructions takes place during the processing of
operation.
 All calculations are performed and all comparisons
(decisions) are made in the ALU.
 The data and instructions, stored in the primary
storage prior to processing, are transferred as and
when needed to the ALU where processing takes
place.

25. Arithmetic and Logic Unit (Cont.)
 Intermediate results generated in the ALU are temporary
transferred back to the primary storage until needed at a
later time. Data may thus move from primary storage to
ALU and back again to storage many times before the
processing is over.
 After the completion of processing, the final results
which are stored in the storage unit are released to an
output device.
 Almost all ALU’s are designed to perform the four basic
arithmetic operations –
- add, subtract, multiply, divide
- logic operations or comparisons such as less than,
equal to, or greater than.

26. Control Unit
 By selecting, interpreting and seeing to the
execution of the program instructions, the control
unit is able to maintain order and direct the
operation of the entire system.
 The control unit acts as a central nervous system
for the other components of the computer.
 It manages and coordinates the entire computer
system.
 It obtains instructions from the program stored in
main memory, interprets the instructions and
issues signals that cause other units of the
system to execute them.

27. CPU Instruction Cycle
 Generally the microprocessor processes all the instructions step
by step. There are typically four stages of an instruction cycle
that the CPU carries out:
 1. Fetch: To load an instruction or piece of data from memory
into a CPU's register. All instructions must be fetched before they
can be executed. The time it takes to fetch an item is known as
the fetch time or fetch cycle, and is measured in clock ticks.
 2. Decode: In this step the processors decodes the instruction to
understand what instruction is given in it.
 3. Execute: in this step the processor execute the instruction by
reading the effective address from memory if the instruction has
an indirect address.
 4. Write: After executing the processor generates a result and
the result is written to memory.

28. Processors Transistors CPU Speed L2 Cache Front-Side Bus Speed
Celeron 7,500,000 1.06 GHz - 2 GHz 256 KB, full speed 133 MHz and 400 MHz
Pentium II 7,500,000 233 MHz - 450 MHz 512 KB, half speed 100 MHz
Pentium III 9,500,000 450 MHz - 1 GHz 256 KB, full speed 133 MHz
Pentium III Xeon 28,100,000 500 MHz - 1 GHz
256 KB - 2 MB,
full speed
100 MHz
Pentium 4 55,000,000 1.4 GHz - 3.4 GHz 256 KB, full speed 800 MHz
K6-II 9,300,000 500 MHz - 550 MHz N/A 100 MHz
K6-III 21,300,000 400 MHz - 450 MHz 256 KB, full speed 100 MHz
Athlon (K7) 22,000,000 850 MHz - 1.2 GHz 256 KB, full speed 200 MHz and 266 MHz
Athlon XP 37,500,000 1.67 GHz 384 KB, full speed 266 MHz
Duron N/A 700-800 MHz 64 KB, full speed 200 MHz
Athlon 64 105,900,000 800 MHz 1 MB, half speed 1.6 GHz
PowerPC G3 6,500,000 233 MHz - 333 MHz
512 KB, 1 MB,
half speed
100 MHz
PowerPC G4 10,500,000 400 MHz - 800 MHz 1 MB, half speed 100 MHz
PowerPC G5 58,000,000 2.5GHz 512 KB 900MHz - 1.25GHz
Microprocessor Comparison Chart

29. Photo of some CPU /Processors

30. What is Duo/Quad/Multi Core?
 A multi-core CPU (or chip-level multiprocessor, CMP)
combines two or more independent cores into a single
package composed of a single integrated circuit (IC), called a
die, or more dies packaged together. A processor with all
cores on a single die is called a monolithic processor.
 A multi-core microprocessor implements multiprocessing in a
single physical package.
 A dual-core processor contains two cores and a quad-core
processor contains four cores.
 A system with N cores is effective when it is presented with N
or more threads concurrently

31. What is Duo Core?
Diagram of an Intel Core 2 dual
core processor, with CPU-local
Level 1 caches, and a shared,
on-die Level 2 cache.
Intel Core 2 Duo E6600 is a
dual core processor

32. Thank you !!