Notes, summaries, assignments, exams, and problems for Computers

Code in MIPS to add the 4 integer variables: a, b, c, d.

Add e,a,b # a gets b+c or a,b,c # a gets b+c

Add e,e,c # a gets a+dor a,a,c, # a gets a+d

Add e,e,d # a gets a+ eor a,a,e # a gets a+e

Code in MIPS for: f = (g + h) ‐ (i + j);

or #f,.., j are mapped to $s0, ., $s4
add t0,g,h #temp t0=g+hadd $t0,$s1,$s2

add t1,i,j #temp t1=i+jadd $t1,$s3,$s4

sub f,t0,t1 #f=t0-t1sub $s0,$t0,$t1

Why the size of a register is 32 bit?

32 bit occurs frequently and thus in MIPS, it has a special name ‘word’. Size 32 aligns well with the MIPS instruction format.

‘MIPS is Big Endian’ – what does it mean?

Most significant byte at least address of a word.

What are lw and sw instructions used for?

MIPS data transfer instructions with an address to access particular... Continue reading "MIPS Code Examples and Register Optimization" »

FIR Filters

A Finite Impulse Response (FIR) filter is characterized by its finite-duration impulse response, settling to zero in a finite time. Unlike Infinite Impulse Response (IIR) filters, which can have internal feedback and respond indefinitely, an Nth-order discrete-time FIR filter's impulse response lasts precisely N+1 samples. FIR filters are predominantly implemented in software and can be continuous-time analog or digital and discrete-time.

Transfer Function of FIR Filter

Frequency Response

IIR Filters

An Infinite Impulse Response (IIR) filter is a recursive filter where the output is calculated using current and previous inputs and outputs. This feedback mechanism within the filter structure is a defining characteristic. IIR filter design... Continue reading "FIR vs. IIR Filters: Advantages, Disadvantages, & Structures" »

What is a Basic Block?

A basic block is a sequence of instructions with no embedded branches (except at the end) and no branch targets (except at the beginning). A compiler identifies basic blocks for optimization. An advanced processor can accelerate the execution of basic blocks.

Six Steps Involved in Procedure Calling

1. Place parameters in registers.
2. Transfer control to the procedure.
3. Acquire storage resources.
4. Perform the desired operation.
5. Place the result in a register for the caller.
6. Return to the point of origin.

Register Saving Responsibilities

Between the caller and callee, the responsibility for saving registers is as follows:

• Temporary registers ($t*): Can be overwritten by the callee.
• Saved temporary registers ($s*): Saved and restored by the

Dynamic Table Generator

ROW:
COL:

EXPLAIN WHICH FACTORS CAN AFFECT STORE IMAGE, DESIGN AND OPERATION COMMITMENT:

It's people’s desire to maintain consistency with previous deeds or choices. Once they have made a decision, they tend to move ahead automatically, convinced that they have made the right choice. SOCIAL PROOF: It's a factor of influence rooted in the maxim “if everybody’s doing it, it must be okay.” Aside from word-of-mouth advertising, a store can convey a message of social proof by attracting people into or in front of the store. AUTHORITY: People do many things simply because they are directed by an authority figure to do so, and store merchants often rely on this principle to sell their products. High-end items, such as jewelry, artwork, and rare collectibles,... Continue reading "Factors Affecting Store Image and Design" »

Which C development tool may add automatically malicious source code to the original application source code?

C Preprocessor

Which C software development tool may inadvertently add compiled object/binary code to the original compiled application object code?

Linker or Linkage Editor

If two programmers are developing two separate files a.c and b.c to be merged into one source code before compilation, and one declares in a.c global integer variable int j; how should the other programmer declare and use the same integer variable j in the source code b.c. Write a line of code that allows the second programmer to use in b.c declaration of variable j from the first file a.c?

extern int j;

What does ELF specify?

Executable file format, Executable file header,... Continue reading "C Development Tools and Functions: A Comprehensive Guide" »

Functions of Operating Systems

Processor Management

The Operating System distributes the processor between different programs.

Random Access Memory Management

The Operating System coordinates the memory space that each application has. When physical memory is insufficient, the Operating System can create a "virtual memory" on the hard disk.

Input/Output Management

The Operating System allows the unification of program access to material resources through controllers.

Execution of Application Administration

The Operating System is responsible for ensuring that applications run smoothly.

Authorization Management

Guarantees that resources are only used by programs and users with the corresponding authorizations.

File Management

The Operating System manages... Continue reading "Operating Systems: Functions, Components, and Network Basics" »

Understanding Flowcharts

The pictorial or graphical representation of the flow of a program is known as a flowchart. If algorithms or programs are displayed in the form of a picture, then it will be more noticeable and recognizable. We only need to know some specific shapes to represent each process or action. The fundamental shapes and descriptions used in flowcharts are as follows:

• Rhombus: For decision-making and branching the flow of execution.
• Rectangle: For processing and assigning variables.
• Parallelogram: Accessing inputs and printing outputs.
• Rectangle with Curved Edges: Start/Begin or Stop/End of the program execution.
• Circle: Connectors to continue the flow of execution.
• Arrow: Represents the direction of the flow of execution.

Programming

The Evolution of Mobile Phones

Mobile phones, also known as cell phones, emerged in the 1980s as bulky, analog devices relying on unencoded radio wave transmissions. These early models quickly evolved, shrinking in size and transitioning to digital technology, ushering in the second generation (2G) era. This shift enabled faster transmission speeds and paved the way for features like images, messaging, and sound.

Advancements in Technology: 3G and 4G

The early 2000s witnessed remarkable technological leaps with the introduction of 3G in 2001, followed by 3G+ and 4G. These advancements significantly boosted speed and capacity, transforming mobile phones into versatile multimedia devices capable of much more than just making calls.

How Cell Phones