# I need some help here engineers on digital circuits.I have done decoder but am stuck with sub circuits.

#### eddkim

Joined May 5, 2020
18
For this assignment you must implement a simple simulation of the velocity (speed) of a car. The simulation has two inputs. Input 1 (V) represents the Current velocity (0-7). Input 2 (A) represents the acceleration (or deceleration)and the resulting velocity change in a single time unit of the simulation. An A value of 1, 2, or 3 means the car decelerates (reduces its velocity) by 1, 2, or 3 velocity units. The acceleration is successful if the final Velocity is in the range 0-7, where 0 is stopped, and 7 is maximum velocity.Examples: 1. Velocity = 5, A = 2 : 5 – 2 = 3. 3 is between 0 and 7. This acceleration was successful.2. Velocity = 2, A = 3 : 2 - 3 = -1. -1 is not between 0 and 7. This acceleration was unsuccessful.3. Velocity = 6, A = 1 : 6 – 1 = 5. 5 is between 0 and 7. This acceleration was successful.An A value of 4, 5, or 6 means the car accelerates (increases its velocity) by 1, 2, or 3 Velocity units. The acceleration is successful if the final Velocity is in the range 0-7 where 0 is stopped, and 7 is maximum velocity.Examples:1. Velocity = 5, A = 6, speed increase is 3 : 5 + 3 = 8. 8 is not between 0 and 7. This acceleration was unsuccessful.2. Velocity = 2, A = 5, speed increase is 2 : 2 + 2 = 4. 4 is between 0 and 7. This acceleration was successful.3. Velocity = 6, A = 4, speed increase is 1 : 6 + 1 = 7. 7 is between 0 and 7. This acceleration was successful.An A value of 0 means there is no change to the Velocity. This acceleration will always be successful.An A value of 7 means that the turbo button has been pressed and the Velocity moves to its maximum value (7). This acceleration will be successful if the current velocity is not 0.Note:The examples on this page represent only some selected cases. There are (many) more cases that result in successful or unsuccessful accelerations. Your circuit must correctly show a successful or unsuccessful acceleration for each possible case.

1007ICT / 7611ICT Computer Systems and Networks Assignment – Trimester 1, 20205 V1.1a The Velocity (V) will be represented by three inputs (3 bits). The three V inputs are named as V1, V2, and V3. The table below shows the assignment of bits to each V value for V1, V2, and V3. Note the order of these bits, V1 is on the left.The acceleration (A) that we want to apply will be represented by three inputs(3 bits). The three A inputs are named as A1, A2, and A3. The table below shows the assignment of bits to each A value for A1, A2, and A3. Note the order of these bits, A1 is on the left. V and A InputsPart ACircuit Option 1: Part A Only (35 marks):The implementation for this part must use only the three basic logic gates(AND, OR, NOT) with maximum 2 inputs. No other logic gates or circuits are permitted.You are required to implement a circuit where the user (you) can input a value for the Velocity (V) using value (V1, V2, and V3) and an acceleration to apply(A) using value (A1, A2, and A3) and the circuit decodes the V1, V2, V3 and A1, A2, A3 values using a decoder (see lecture notes) made up of only thepermitted logic gates to determine if the acceleration is successful or unsuccessful based on the requirements section on page 4 is met.The output is via a single LED labelled Successful which is lit if V = 0, 1, 2, 3, 4, 5, 6, or 7 after a successful acceleration is applied (A = 0, 1, 2, 3, 4, 5, 6, or 7). The LED is not lit for any values of V or A or where the applied acceleration is unsuccessful

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#### eddkim

Joined May 5, 2020
18
I got truth table for sub circuits but i dont know how to handle them

#### dl324

Joined Mar 30, 2015
15,534
I got truth table for sub circuits but i dont know how to handle them
Post the work you've done so far so we can see where you're getting stuck.

#### eddkim

Joined May 5, 2020
18
I got truth table for sub circuits but i dont know how to handle them.Any help on understanding this please
Post the work you've done so far so we can see where you're getting stuck.
I already have drawn two decoders with 3 to 8 inputs for c1,c2,c2, and A1,A2,A3,
The next thing i need to do is to draw subcircuits

This are decoders for accelaration and velocity.I already have the truth table here.I need some help in interpreting the truth table and applying them on the gates

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#### eddkim

Joined May 5, 2020
18
Post the work you've done so far so we can see where you're getting stuck.
Are we allowed to share the personal details like email?

#### WBahn

Joined Mar 31, 2012
28,465
This are decoders for accelaration and velocity.I already have the truth table here.I need some help in interpreting the truth table and applying them on the gates
You need help interpreting a truth table that YOU came up with?

#### WBahn

Joined Mar 31, 2012
28,465
Are we allowed to share the personal details like email?
Please don't. E-mails posted on forums are magnets for spam bots and subject both you to a flood of spam and us to being seen as a target-rich environment. Exchange such information via private messaging.

#### eddkim

Joined May 5, 2020
18
You need help interpreting a truth table that YOU came up with?
yes please.I need help in interpreting them so that i could apply in the representations to the subcircuits to be combined with the decoders above using logic gates

#### dl324

Joined Mar 30, 2015
15,534
This are decoders for accelaration and velocity.I already have the truth table here.I need some help in interpreting the truth table and applying them on the gates
Post the truth table and how you derived the decoders. It would also be helpful if you posted the problem text in the original format so it's easier to read.

Your circuits would be easier to follow if you avoided unnecessary wire bends.

#### WBahn

Joined Mar 31, 2012
28,465
yes please.I need help in interpreting them so that i could apply in the representations to the subcircuits to be combined with the decoders above using logic gates
How did you come up with the truth table in such a way that you can't interpret your own work?

Or did you get the truth table from some other source and it doesn't represent your work to begin with?

#### eddkim

Joined May 5, 2020
18
How did you come up with the truth table in such a way that you can't interpret your own work?

Or did you get the truth table from some other source and it doesn't represent your work to begin with?
The first part uses 3 to 8 decoder.I just picked it from the current class notes.Let me attach the original document and the truth table i have then you will to guide me

#### eddkim

Joined May 5, 2020
18
This the original document,I will attach the truth table shortly

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#### eddkim

Joined May 5, 2020
18
Post the truth table and how you derived the decoders. It would also be helpful if you posted the problem text in the original format so it's easier to read.

Your circuits would be easier to follow if you avoided unnecessary wire bends.
yea i will do it in a few minutes.thanks

yea i will do it in a few minutes.thanks

yea i will do it in a few minutes.thanks
The truth table was just a mathematical concept>But the logism concept is what iam struggling with

#### WBahn

Joined Mar 31, 2012
28,465
Oh, I didn't realize that we were on the clock and that you demand that we drop everything else and give immediate attention to your needs.

That leaves me out. Good day.

#### eddkim

Joined May 5, 2020
18
Oh, I didn't realize that we were on the clock and that you demand that we drop everything else and give immediate attention to your needs.

That leaves me out. Good day.
No worries mate.Any time you free post something.It might be helpful for all those learning this.Thanks

#### dl324

Joined Mar 30, 2015
15,534
This the original document,I will attach the truth table shortly
Three different assignments in the same packet; your instructor is lazy. Which part(s) are you doing?

#### eddkim

Joined May 5, 2020
18
Iam doing part A at the moment then part B later.Thanks

#### dl324

Joined Mar 30, 2015
15,534
Iam doing part A at the moment then part B later.Thanks
Tell us what the circuit you posted is supposed to do and how you derived it.

I'm not going to show you how to redraw your schematic because you're being graded on neatness. What you drew doesn't qualify as neat in my opinion.

#### eddkim

Joined May 5, 2020
18
Tell us what the circuit you posted is supposed to do and how you derived it.

I'm not going to show you how to redraw your schematic because you're being graded on neatness. What you drew doesn't qualify as neat in my opinion.
Iam yet to make it neat by using comparators,counters to make it simple.I will re-organise the ones i get what is expected

#### dl324

Joined Mar 30, 2015
15,534
This are decoders for accelaration and velocity.I already have the truth table here.I need some help in interpreting the truth table and applying them on the gates
How do your labels correspond to the problem text? You have V0, V1, and V2. The problem says you have V1, V2, and V3.