Arduino/C3/Digital-Logic-Design-with-Arduino/English-timed

Time	Narration
00:01	Welcome to the Spoken Tutorial on Digital Logic Design with Arduino.
00:07	In this tutorial, we will learn to: Implement and verify the AND, OR and XOR operations in assembly.
00:17	Implement and verify simple Combinational Logic.
00:21	To follow this tutorial, you should have basic knowledge of: Electronics and Assembly language
00:31	To record this tutorial, I am using: Arduino UNO Board
00:38	And Ubuntu Linux operating system version 14.04
00:44	We also require some external devices such as: Breadboard
00:51	Arduino UNO Board
00:54	Seven Segment Display
00:57	220-ohm Resistor
01:00	Decoder (7447 IC) and Jumper Wires
01:07	We will use the same circuit setup as we did for the decoder in the earlier tutorial.
01:14	Let us see the live connection setup.
01:17	Now we will write an assembly program to verify the logical AND operations.
01:24	Open any text editor and type the following program.
01:29	m328Pdef.inc file and the source code are available in the code files link of this tutorial.
01:38	You can download and use it.
01:41	The highlighted code configures pins 2, 3, 4 and 5 of the Arduino as output pins.
01:49	We are considering only the first bit of r16 and r17 for our boolean operations. Here, both are 1.
02:00	This line performs bitwise AND operation on the bits of r16 and r17. The result is stored in r16.
02:12	The rest of the program takes care of displaying this output.
02:17	The LSB of r16 has our result. This has to be shifted by two positions to the left.
02:26	This line of code calls the loop named loopw.
02:31	This loop takes care of shifting the LSB of r16 twice.
02:38	The value in r16 is sent to PORTD. This displays either 0 or 1 on the Seven segment display.
02:48	Here, contents of r16 are left shifted once. Then the value of r20 is decremented by 1.
02:58	If the value of r20 is not equal to zero, the loop is repeated again.
03:05	I’ll save the code as boolean.asm in the home slash spoken slash Assembly folder.
03:15	Switch to the terminal.
03:18	Go to the folder where boolean.asm file is saved. Type, avra boolean.asm and press Enter.
03:29	This will assemble the code and create a file boolean.hex.
03:34	Let us clear the screen.
03:36	Next we need to upload the code to the Arduino.
03:41	For this, type avrdude space hyphen p space atmega328p space hyphen c space arduino space hyphen b space 115200 space hyphen capital P space forward slash dev forward slash ttyACM0 space hyphen capital U space flash colon wcolon boolean dot hex and press Enter.
04:17	Now you can see that the digit one on the seven segment display is glowing.
04:23	Pause the tutorial and do the below assignment.
04:27	Modify the values of r16 and r17 to verify the rest of the truth table of AND.
04:35	Replace the keyword and in the program with or to perform logical OR operation.
04:42	Replace the keyword and in the program with xor to perform logical XOR operation.
04:49	Next, we will implement and verify few simple combinational logics.
04:55	Let us see the live connection setup. It will be the same as the previous setup.
05:02	We are going to implement these equations in our program and verify their truth table.
05:09	This is the truth table for the equations shown above.
05:14	Here W, X, Y and Z are the inputs.
05:19	A, B, C and D are the outputs. Let us consider the first row of the truth table. Thus, all the inputs will be zeros.
05:31	As per the truth table, we can expect the output as 1.
05:36	We will display the output on the seven segment display.
05:40	Let us write an assembly program to implement and verify these equations.
05:46	Open any text editor and type the following program.
05:50	Let me explain the program.
05:53	This line configures pins 2,3,4 and 5 of the Arduino as output pins.
06:00	r30 is a dummy variable for storing the output.
06:05	The values of input variables W, X, Y and Z are stored in registers r17, r18, r19 and r20 respectively.
06:16	The values of r17, r18, r19 and r20 are stored in the dummy variables r0, r1, r2 and r3.
06:27	These values are used to restore the original registers after performing operations.
06:35	The comp subroutine is used to find the complement of a variable.
06:41	The complement of W, X, Y and Z are calculated and stored in r21, r22, r23 and r24 respectively.
06:52	The values of r21, r22, r23 and r24 are stored in the dummy variables r4, r5, r6 and r7.
07:04	Note that A is nothing but the complement of W. Now, we have implemented the first equation.
07:12	Next, we perform two left shift operations and store the value in r30. Thus, the third bit of the r30 has the value of A.
07:24	The reload subroutine reloads the values r0, r1, r2, r3, r4, r5, r6 and r7 from its copies.
07:36	They might have changed during previous operations.
07:41	The logic for B is implemented and the result is stored in r0.
07:47	The value in r0 is left shifted thrice and stored in r30.
07:54	Now, the fourth bit of r30 holds the result of B.
08:00	The logic for C is implemented and the result is stored in r0.
08:06	The value in r0 is left shifted four times and stored in r30.
08:13	Now, the fifth bit of r30 holds the result of C.
08:19	The logic for D is implemented and the result is stored in r0.
08:25	The value in r0 is left shifted five times and stored in r30.
08:32	Now, the sixth bit of r30 holds the result of D.
08:38	Finally, the value stored in r30 is sent to PORTD to be displayed.
08:46	Save the code as combination.asm in the home slash spoken slash Assembly folder.
08:55	Switch to the terminal.
08:58	Type, avra space combination.asm and press Enter.
09:05	This will assemble the code and create a file combination.hex. Let us clear the terminal
09:14	To upload, press the up arrow to get the previous command.
09:19	Now change the filename as shown and press Enter.
09:26	Now you can verify the truth table with the output shown on the seven-segment display.
09:34	Pause the tutorial and do the below assignment.
09:38	Change the values of W, X, Y and Z and verify different rows of the truth table.
09:46	This brings us to the end of this tutorial. Let us summarize.
09:52	In this tutorial, we learnt to: Implement and verify the AND, OR and XOR operations in assembly.
10:01	Implement and verify simple Combinational Logic.
10:05	The video at the following link summarizes the Spoken Tutorial project. Please download and watch it.
10:13	The Spoken Tutorial Project Team conducts workshops and gives certificates. For more details, please write to us.
10:23	Please post your timed queries in this forum.
10:27	Spoken Tutorial project is funded by NMEICT, MHRD, Government of India. More information on this mission is available at this link.
10:38	This tutorial has been contributed by FOSSEE and Spoken Tutorial Project, IIT Bombay.   This is Priya from IIT Bombay signing off. Thanks for watching.

Contributors and Content Editors

PoojaMoolya, Sandhya.np14