CMPE 120 - Computer Organization and Architecture
- Learning Objectives
- Reference Material
- Programming Languages
- CPU Arhitecture
- Operating System
Upon successful completion of this course, students will be able to:
1. Understand digital logic and how it is used to build a computer system.
2. Explain how CPU functions to run a software program.
3. Develop assembly programs to control the operation of the CPU.
4. Understand the format of instructions and their operations.
5. Understand the role of the other components of a computer system such as buses and memories and how
they work together.
- Number System (CLO 1)
- Units (CLO 1)
- Kibibytes, Kilobytes etc.
- Hardware Architecture (CLO 2)
- Data bus
- Address bus
- On-chip peripherals review
- Compilers and Programming Languages (CLO 3, CLO 4)
- Compiled vs. Interpreted languages
- C compiler
- Hands-on with a compiler
In the past, we needed to setup special tools on a local computer (i.e.: your laptop) to test software. In the modern era, the advanced made by software developers have led us to several tools we can use to understand a machine's instruction set.
- Python Interpreters
- Assembly and Emulators
- Logic Emulators
Books and Online Resources
Really awesome book from Robert Plantz:
The number system holds significance in terms of writing and expressing code to a computer, typically in a programming language. Note that we (as humans) do not use hex or binary numbers that much outside of the computer science domain. For example, we don't walk into a supermarket and read prices in binary such as
Often times in programming, we need to express numbers more quickly, and we might say int
x = 0x10000000 to quickly indicate 32-bit value with
bit31 set to 1. Notation
x = 0x10000000 is easier than writing
x = 268435456 which would be more cryptic for a programmer to realize the significance of because the reader of the programming code will not be able to quickly realize that it is specifically setting
bit31 to value of
Typical numbers we are familiar with are decimals which are technically "base 10" numbers. So an ordinary number that we may be aware of such as 123 can be written as 12310.
The number 123 could also be written as:
1*102 +2*101 +3*100 which is equal to
100 + 20 + 3 =12310
Binary numbers are always 1s and 0s only. Similar to decimal numbers, binary numbers increase in powers of 2, rather than powers of 10. Binary numbers are written by with the "0b" notation, such as 0b1100
For example, binary
0b101 can be written as:
1*22 +0*21 +1*20 which is equal to
4 + 0 + 1 = 510
One digit of a hex number can count from 0-15, but since we have to represent the hex number using a single character, the numbers 0-9 are usual numbers, and the numbers 10-15 are represented by A, B, C, D, E, F
Where decimal is a power of 10, and binary is power of 2, hex numbers are powers of 16. Hex numbers are written with the "0x" notation, such as 0x10.
For example, hex
0x12 can be written as:
1*161 +2*160 which is equal to
16 + 2 = 1810
As another example, hex
0xC5 can be written as:
12*161 +5*160 which is equal to
192 + 5 = 19710
Decimal to Binary
Decimal (base 10) numbers can be converted in a couple of different ways as described here. One of the methods is to continue dividing by 2 and note down the remainder as described in the image below. The article above also describes a potentially faster method of conversion so be sure to read it!
Please try converting the following to binary:
Decimal to Hex
Decimal to hex is similar to Decimal to Binary except that we are dealing with powers of 16 rather than powers of 2.
My favorite method of conversion from decimal to hex is to first convert the number to binary. For example, let's start with a large number such as 23912. We can use the Decimal to Binary method to convert this first to binary:
- Split it up to nibbles:
0b101 1101 0110 1000
- Then use the lookup table listed in Hex to Binary:
Please try converting the following to hex:
Hex to Binary
The following table can be utilized to convert hex to binary very instantly:
First row is HEX, and the second row is binary. For whatever hex number we wish to convert, we simply locate its equivalent in binary. For instance, if we wish to convert
0x5 to binary, it is
0xA5 would be
0b1010.0101 as you can convert one "nibble" (4-bits) at a time.
Let's take another example to convert
0x1BF to binary; simply break it down by "nibbles":
0b0001 1011 1111
Please try converting the following to binary:
Hex to Decimal
For Hex to Binary, we used a lookup table as a "cheat code" :). For Hex to decimal, it would be easier to re-write the numbers as powers of 16. For example, to convert
0x1BF to decimal, we can break it down to:
1 * 162-->
11 * 161-->
15 * 160-->
256+176+15 = 447
Please try converting the following to decimal:
Python Number Converter
Generally speaking, practiced skill cannot be easily forgotten. It is far better to go through the process and practice converting a number, rather than to memorize the process.
Before we get started, have a look at the Tools Page to get started with a Python Interpreter we could use for this exercise.
Number to Printable Hex
def nibble_to_ascii(nibble: int) -> str: """ This is a comment Input: Nibble (4-bits) Output: Single character HEX as a string Example: Input = 10, Output = 'A' Example: Input = 8, Output = '8' """ table = ['0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'] return table[nibble] def to_hex(number: int) -> str: """ This is a comment Input: Number (integer) Output: String Example: Input = 43605, Output = "0xAA55" """ answer = "" # Forever loop while True: # Integer divide using the // operator quotient = number // 16 # Get the remainder using the % operator remainder = number % 16 # Accumulate result answer = nibble_to_ascii(remainder) + answer # Set the number we need to use for next time number = quotient # We break the "loop" when division turns to zero if (quotient == 0): break return "0x" + answer print(to_hex(123456789)) print(to_hex(0b1010101)) print(to_hex(0xDEADBEEF))
Write a function
to_binary() that takes a number, and returns the string equivalent version of the number in binary. You can borrow the template above of
to_hex() function and most of the logic might be similar except that we would be dividing number by 2 rather than 16.
I fear that most of the technical articles on the Internet misinterpret some of the common storage units.