Cache memory basics of raid decrement operator relational operator logical operators flow control statements break and continue loop control statements eapcet material
CACHE MEMORY :
It is an
interface memory in between processor and the main memory
Always cache
memory state is zero
It holds the
data when the processor and ram is buzy
RAM is
volatile
Characteristics
of memory:
Location ,
capacity, unit of transfer, Access method ,
performance, physical type ,physical characteristic ,organization
Location :
cup storage (memory unit)
Internal storage (main
memory)
Processor registers
External storage(HD)
Capacity :
number of words are transmitted per
second either in data bus or
system bus
word (code word or data word)
unit of
transfer : it is used to identify the
destination point of memory
Access
methods :
1. Serial access
2. Random
3. Dynamic
Performance
: number of cycles per second (to identify)
Physical
type : to identify the memory(physical location of the memory)
Physical
characteristic : volatile or non volatile
Organization
----- location same
Locality of
reference :
A data which
is available on the main memory
The main
memory address for the file is called as locality reference
Is is a
temporary address
Ram memory
address
Loops and
sub routines related to locality reference
Nearby
memory
BASICS OF RAID :
Redundant
array of independent disks
(Inexpensive
disks)
It is used
to implement mirror copy’s identical to the permanent storage
It works
with placing data on multiple disks
Raid works
with raid controller
It can be
used as level of obstruction between the os and the physical disks
MODES OF I/O DATA TRANSFER
Transferring
of information between internal storage and external input and out put devices
Programmed
input and out put
Interrupted
input and out put
Direct
memory access
Programmed input and out put :
Cpu requests
I/O
IO Module perform
operations
It is used
to implement sets start bit for the resources
Note:
There are
two states for every device
0 and 1
0-off 1 ready
Cpu checks
start bits periodically for all devices
Each device
contains 1 unique identifier number
Cpu commands
contains unique identifier
Which of the
following operation of I/O data transfer checks for the start bit of the
devices
Programmed
I/o
Which
operation is used to identify the unique identifier number for cpu commands
Programmed
I/O
INTERRUPTED DRIVEN I/O :
Cpu issues
read command to the devices
It gets data
from the peripherals
Cpu requests
for data
The module
uses identify the interrupted
instructions/devices
Which
operation is used to requests data and gets the data from the peripherals ---
interrupted driven I/O
DIRECT MEMORY ACCESS :
Transfer
rate is limited
Cpu is tied
up for manageing data transfers
Dma module
must use the bus only(system bus) when the
processor(cpu) does not need it
DMA OPERATION :
Read and
write operations
RECOGNIZE AND ALLOCATE DEVICE ADDRESS
:
It sets the
amount of data to be transferred
Pcb control
receives signal/request from the client/user or some other device who will
allocate address --- dma
General key
points :
Cpu carry’s
the signals from dma/receivers
Dma
controller sends system call to cpu
In what type
of situations dma will sends system call to processor?
When dma
receives instruction from other client/user
Main functionality
of dma controller ----it acts as an interface between main memory and the
processor
Key points :
All IO
operations are connected to IO bus
One chip set
is required to transfer the data from all IO devices to the mother board
IOP also
called as scsi
SCSI : small
computer system interface
DECREMENT OPERATOR :
To decrease the value by 1
Main ()
{
Int i=5;
Pf(“id”,i--)
Main()
(
Int i=5
--i
=4
RELATIONAL OPERATORS:
To implement conditions
Ex :
>,<,>=,<=,==,!=
Ex :
10>20
The written
value in the relational operator either true or false
What is
association of data in comparison operator?
Left to
right
Which of the
following is true about the relational operators?
It is an
operator used to implement conditions
LOGICAL OPERATOR :
Logical
operators are used to implement multiple conditions in a single expression
Ex : logical
and (&&)
Logical or
Logical not(!)
Ip1 ip2
T T T
T F F
F T F
F F F
LOGICAL AND
All i/p are
true then o/p true
If the input
1 is negation of negation of true N(N(T)
N(n(t) and
i/p 2 is n(t) then what is the o/p of logical and
OR GATE :
Logical OR
Any one is
true or all are true
I1 i2 o/p
T T T
T F T
F T F
F F F
If the i/p 1
is not a true and o/p is false then
What is the
o/pof or gate false
OR gate :
Logical OR
Any one is
true or all are true
I1 I2 O/P
T T T
T F T
F T T
F F T
If the i/p 1
is not a true and o/p is false then
What is the
o/p of or gate false
Note : T---F
F---T
Conditional
operators :
To implement
conditionals statements
Ex: int x =
(10>20)? 10 : 20
The o/p of
conditional statement is 20
FLOW CONTROL STATEMENTS :
IF IF ELSE IF SWITCH
IF
ELSE
NESTED IF
IF :
Single
condition code block
Only one
state output
If
(cond)
{
------
--------
}
Single
condition code block identified in ----- if
HINT :
Identifier
is always greater than zero
If(x<0)
{
Printf(“hello”);
}
IF ELSE :
It is a
single condition block based on
T OR F OR
else output
If(cond)
{
---------------
-----------------
}
Else
{
---------
}
Ex : if
(10>20)
Printf(“digital assistant”);
Else
Printf(“ap”)
Else block
is called as false statement
Which of the
following is the false block in if else -------------else
What are the
condition states of if else ? a b both either a or b
When the
false block is executed
Condition is
not true
Condition is
false
IF ELSE IF
Some times
it is called as else if ladder
It is based
on multiple conditions & multiple true statements
Multiple
false statements
Last else is
called as false
If cond(1)
True stmt 2
Else cond 2
True stme 2
Else if cond
n
NESTED IF :
Arrange the
if conditions in AND gate
All the
conditions are based on only one block
If (cond 1)
If (cond 2)
If(cond n)
True (stmt)
There is no
separate else block
Multiple
condition blocks are based on single statement or single o/p
Is called as
nested if
In nested if
last block is called as true statement or block out put
SWITCH
It is
identified by the switch block
Switch()
It can be
devided into individual blocks named as cases
Case 1 case2 ….. casen
The syntax
is related to if else if
Last else is
called as default
Each case
block terminated by the break statement
Switch(expr)
{
Case (i)
------
Break
}
Case (i)
------
Break
}
Case n
………
}
Break
Default
…….
}
Break
statement is used to terminate the case blocks
Swith syntax
is related to if else if
BREAK AND CONTINUE:
Terminate
from code block
How to
terminate the cursor from the method
How to
terminate cursor from the loop
Ans : break
To terminate
the cursor from the conditional code block break
Note : block
statement is used on condition
Int x = 2
Void
display()
{
If(x==3)
Break ;
Printf(“hello”);
CONTINUE :
To move the cursor from its continuous
statement to previous
Note :
No
statements are executed after continue
Void display
()
{
Continue
Printf(“test”);
}
o/p : emply
or blank
GOTO
Abnormal
conditional implementation
It is used to
implement unconditional code block based on “label”
Programme
label is called as block identifier
Label is
identified by the (:) operator
Main()
{
Test:
Printf(“Guntur”);
Go to test ;
}
How to
implement abnormal condition loop --------------goto
How to implement
unconditional code block -------------------goto
Label is
called as block identifier
Goto is
based in label
LOOP CONTROL STATEMENTS
LOOP CONTROL STATEMENTS
Toexecute
the statements more than once
Continuous
execution of statements based on specified condition
1. Terminated loop---- inner loop ,
outer loop
2. Unterminated loop –
goto,break,continue
FOR WHILE CONTINUE
FOR :
It is a multi statement loop
It is also called as statement loop code block
PARTS OF FOR LOOP
Initialization
Test condition
Increment or decrement
INITIALIZATION
To identify the booting index of the loop or initial index or starting
index of the loop
L bond of the loop initialization
Initialization default value zero
TEST CONDITION
It is used to find the last index of loop
To find terminated index, to find last inded
To increase value by 1 or decrease value by 1
REALLOC:
To resize the declare(already allocated buffer)
Syntax :
<ptr location> =<type declaration>realloc(buffer size);
Already declare buffer
Ptr =<int *>realloc(size of(int));
The ptr already declared(existing ) buffer
FREE
To release the already allocated memory
Free (<ptr name>);
Free(ptr);
C TOKENS
IDENTIFIERS
ALPHABETS
KEYWORDS
NUMBERS
CODE BLOCKS
SPECIAL OPERATORS
STATIC CLASSES
AUTO STATIC
EXTERN
REGISTER
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