Everybody said it will be like this...but you never know it until you've gone through it...yes...its Final Year Project...
I'm into my CA2 of my FYP...my project title is "frequency calibration for an oscillator for OOK transmission". As of now, I am all alone (insert forever alone guy picture here) in a cold, dark lab in the depths of the dungeons of engineering(true story)...not fun...
It not really a nightmare(in fact, its quite fun and interesting) until you reach a point where you realised that you have been isolated from society and human contact for a few days and the few incidents of social activity involves going lunch with friends.
From year 1-3, after exams are over, its official over...the sem is over...seriously over...you can play computer games everyday, go find a job, eat unhealthy food, gym and whatever make you happy. But Year 4, even if you finish your exam early, you find yourself spending time doing reports and preparing an hour long presentation(not sure if it is an hour)...I NEED TO GET OUT!!!!
Saturday, December 3, 2011
Monday, October 24, 2011
EE4410: 1 sem in hell and 1 sem in heaven
Last sem I spent a lot of time on EE4410.
It is a module about VLSI, where student are supposed to design something(specified by the lecturer) on cadence.
For my semester, my group was made to design an Analog to Digital Converter(ADC). The premise of the project is that this device would be used in an ECG. So what the system would do is to take in the small signal, amplify it and then convert the analog signal into a digital signal.
Since the frequency of heart rate isn't exactly fast, we are looking at about 100++ Hz (engineers are not very specific unless required) and a resolution of about 10 bits. Below is the reconstructed sinewave after input a sine signal into its input.
So workload for our group was separated into 2 sub-groups. One person to design the Operational Transconductance Amplifer(OTA) and 2 other people to design the ADC. The ADC works based on Successive Approximation logic (SA).
How it works?
Well, when the signal goes into the ADC, a sample and hold block in the circuit will hold the signal. The input of the signal would be pass through a comparator which would compare this signal against a Digital to Analog Converter(DAC). The output of the comparator is passed into a Successive Approximation Register(SAR) which would determine the control logic of the DAC. The DAC is just a capacitor array which tries to convert the digitalised values of the SAR to an analog value so as to be used for comparison.
Design of a comparator
I'll just talk about it for a while.
Well, from the shallowest of levels looking at it, an analog comparator should be able to compare 2 inputs and determine if A is larger than B and appropriately produce a high or low output accordingly.
So we need to note the resolution of the comparator as well as the bandwidth. A 10 bit comparator should at least be able to to detect a difference of Full-scale/2^10, so as to appropriate digital output. That is resolution. Bandwidth is that it should be able to work at the required frequency that you need.
A simple comparator usually have 3 stages. Pre-amplifier, latch and buffer. The pre-amplifier is important due to issues such as metastability as well as kickback. Maybe I should just discuss that first.
Metastability is an issue pertaining to the latch of the comparator. It occurs when the latch is unable to latch onto a high or a low. So how the pre-amp solves this is by providing a gain into the input to increase the initial voltage so as to help the latch to reach its high or low state faster. Other ways to reduce this is to reduce the length of the MOSFETs, else we can use a double latch. But Metastability is not really an issue in EE4410 since the minimum clock time is 5kHz, which is quite low.
Upon evaluation(evalutation being like testing the real fabricated chip), our comparator can work even at 50KHz(I sure remember it can work at 80kHz, but overcommiting is bothersome).
Kickback, on the other hand is one royal pain in the ass. But learning how to solve the kickback would improve your INL and DNL and you would really learn how to design a pre-amp(impt clue). Since power consumption is an issue in EE4410, using a synchronous comparator, sure cuts down the power consumed, but it comes at a price of complication in the form of kickback.
Anyway, getting back to pre-amp, its usually just a differential with maybe a common source amplifier connected afterwards. The next stage being the latch is use to pull the output up or down based on the differential output. Its a rather simple design so really nothing much to talk about it. The final stage is the buffer. Nothing much, since its just a digital buffer, think of it as 2 inverters used to pull the output from the latch.
Looking back, it was a hectic but fun module. The GA was helpful, but they cannot tell you very much(otherwise they might as well do it for you). The first sem is usually very time consuming and stressful. The next sem is usually better because it only left to testing the circuit.
I better get back to my work. I am trying to figure out how to design a charge pump...seriously no idea...haha...
It is a module about VLSI, where student are supposed to design something(specified by the lecturer) on cadence.
For my semester, my group was made to design an Analog to Digital Converter(ADC). The premise of the project is that this device would be used in an ECG. So what the system would do is to take in the small signal, amplify it and then convert the analog signal into a digital signal.
Since the frequency of heart rate isn't exactly fast, we are looking at about 100++ Hz (engineers are not very specific unless required) and a resolution of about 10 bits. Below is the reconstructed sinewave after input a sine signal into its input.
So workload for our group was separated into 2 sub-groups. One person to design the Operational Transconductance Amplifer(OTA) and 2 other people to design the ADC. The ADC works based on Successive Approximation logic (SA).
How it works?
Well, when the signal goes into the ADC, a sample and hold block in the circuit will hold the signal. The input of the signal would be pass through a comparator which would compare this signal against a Digital to Analog Converter(DAC). The output of the comparator is passed into a Successive Approximation Register(SAR) which would determine the control logic of the DAC. The DAC is just a capacitor array which tries to convert the digitalised values of the SAR to an analog value so as to be used for comparison.
I was assigned to design the comparator and the DAC. I doubt there is any need to discuss about the DAC since it is just a capacitor array and a switch array. The only thing to note is to do the layout in common centroid to reduce capacitor mismatch. Layout is something that is not sufficiently taught in this module. Plug and play is sufficient to get your device working, but in the industry, drawing layout is a skill.
Design of a comparator
I'll just talk about it for a while.
Well, from the shallowest of levels looking at it, an analog comparator should be able to compare 2 inputs and determine if A is larger than B and appropriately produce a high or low output accordingly.
So we need to note the resolution of the comparator as well as the bandwidth. A 10 bit comparator should at least be able to to detect a difference of Full-scale/2^10, so as to appropriate digital output. That is resolution. Bandwidth is that it should be able to work at the required frequency that you need.
A simple comparator usually have 3 stages. Pre-amplifier, latch and buffer. The pre-amplifier is important due to issues such as metastability as well as kickback. Maybe I should just discuss that first.
Metastability is an issue pertaining to the latch of the comparator. It occurs when the latch is unable to latch onto a high or a low. So how the pre-amp solves this is by providing a gain into the input to increase the initial voltage so as to help the latch to reach its high or low state faster. Other ways to reduce this is to reduce the length of the MOSFETs, else we can use a double latch. But Metastability is not really an issue in EE4410 since the minimum clock time is 5kHz, which is quite low.
Upon evaluation(evalutation being like testing the real fabricated chip), our comparator can work even at 50KHz(I sure remember it can work at 80kHz, but overcommiting is bothersome).
Kickback, on the other hand is one royal pain in the ass. But learning how to solve the kickback would improve your INL and DNL and you would really learn how to design a pre-amp(impt clue). Since power consumption is an issue in EE4410, using a synchronous comparator, sure cuts down the power consumed, but it comes at a price of complication in the form of kickback.
Anyway, getting back to pre-amp, its usually just a differential with maybe a common source amplifier connected afterwards. The next stage being the latch is use to pull the output up or down based on the differential output. Its a rather simple design so really nothing much to talk about it. The final stage is the buffer. Nothing much, since its just a digital buffer, think of it as 2 inverters used to pull the output from the latch.
Looking back, it was a hectic but fun module. The GA was helpful, but they cannot tell you very much(otherwise they might as well do it for you). The first sem is usually very time consuming and stressful. The next sem is usually better because it only left to testing the circuit.
I better get back to my work. I am trying to figure out how to design a charge pump...seriously no idea...haha...
Friday, October 21, 2011
God's grace
It's been a really long while since I visited this site.
Work has been heavy and time has been scarce.
As I embark into my final year and dealing deeping within my specialisation,
I find that taking time out for external activities gradually become harder.
Fortunately, by God's grace, it seems that everything seems to be pulling through.
Never would I have thought this, especially looking back on those crappy stuff happened to me almost a year and a half ago. It seems that it would have all ended that...but by God's grace, seems that everything pulled through.
Last Semester was one big rush. EE4410 design project, staying in the lab drawing designs and layouts until midnight, only to have to take taxi home.
"He gives strength to the weary and increase the power of the weak"
Isaiah 40:29
Sometimes we are all so small to see how big our father God truly is.
Anyway, I did pretty well last semester, which I cannot understand why.
The fabricated chip worked very well and I managed to take the data successfully and it fulfils the specifications nicely. Looking forward to writing the report.
Work has been heavy and time has been scarce.
As I embark into my final year and dealing deeping within my specialisation,
I find that taking time out for external activities gradually become harder.
Fortunately, by God's grace, it seems that everything seems to be pulling through.
Never would I have thought this, especially looking back on those crappy stuff happened to me almost a year and a half ago. It seems that it would have all ended that...but by God's grace, seems that everything pulled through.
Last Semester was one big rush. EE4410 design project, staying in the lab drawing designs and layouts until midnight, only to have to take taxi home.
"He gives strength to the weary and increase the power of the weak"
Isaiah 40:29
Sometimes we are all so small to see how big our father God truly is.
Anyway, I did pretty well last semester, which I cannot understand why.
The fabricated chip worked very well and I managed to take the data successfully and it fulfils the specifications nicely. Looking forward to writing the report.
Tuesday, April 5, 2011
Rocky says it best about life.
I was watching Rocky Balboa the other day. Nice movie, epic quotes. So Rocky was saying this to his son, when his son was asking him, why he wanted to get back into boxing. His son felt he was living under his father's shadow. Rocky Balboa: I'd hold you up to say to your mother, "this kid's gonna be the best kid in the world. This kid's gonna be somebody better than anybody I ever knew." And you grew up good and wonderful. It was great just watching you, every day was like a privilige. Then the time come for you to be your own man and take on the world, and you did. But somewhere along the line, you changed. You stopped being you. You let people stick a finger in your face and tell you you're no good. And when things got hard, you started looking for something to blame, like a big shadow. Let me tell you something you already know. The world ain't all sunshine and rainbows. It's a very mean and nasty place and I don't care how tough you are it will beat you to your knees and keep you there permanently if you let it. You, me, or nobody is gonna hit as hard as life. But it ain't about how hard ya hit. It's about how hard you can get it and keep moving forward. How much you can take and keep moving forward. That's how winning is done! Now if you know what you're worth then go out and get what you're worth. But ya gotta be willing to take the hits, and not pointing fingers saying you ain't where you wanna be because of him, or her, or anybody! Cowards do that and that ain't you! You're better than that! I'm always gonna love you no matter what. No matter what happens. You're my son and you're my blood. You're the best thing in my life. But until you start believing in yourself, ya ain't gonna have a life. Don't forget to visit your mother.
Sunday, March 13, 2011
WWBD: what would Bond do?
Target: I heart UTown sweets
Location: MPSH X, where I have no idea what is X
ETA: Afternoon 3
My bro went to the NUS open house yesterday and brought back some freebies.
I thought most of it was pretty okay...but there was one goodie that caught my attention.
This one.
I know the bottle looks like brands essence of chicken, but it rather nice, isn't it?
The "I heart Utown" was quite well designed.
But that is not the main allure. Its the candy inside that is very interesting. Every candy has its own unique design. I am actually very impressed with the effort placed into just making one gift.
Well, so when my brother brought it back, I thought "hey, this is pretty cool...so I decided to take one...then another... and another... before I knew it, it was almost finish.
And that was yesterday. So today, as I was going to school to study, I saw some people carrying the Openhouse bag. Then it hit me that the Openhouse was still opened. Then I thought to myself "hey, lets go get some candy...hehe...hehe...BWAHAHAHAHAHAHA".
So I went to MPSH to get some UTOWN CANDY!!!!
I managed to pass through crowds of people disguised as a prospective student, getting goodie bags and acting like a new student. Its not like they would know or care, but who cares...I'm just saying this to build up the tension. Heck would I know where to find it...Then I trusted my senses, It should be where the faculties are...level 2.
As I entered the MPSH on the second floor, what caught my attention was the U Town booth. I knew it had to be there, otherwise where else could it be? So I walked over the booth, lo and behold sat bottles of UTown candy, right smack on the center of the table. I could just walk over and get it, but it would seem like I was just too damn cheapskate.
So I walked over and took a brochure. As a spy, you must always create a decoy. Decoys are crucial for the success and failure of missions, you can always over-plan but you can never under-plan. In a life as a spy, every decision is a life and death matter. If you want the candy, make it look like the candy wants you.
I took and brochure and briefly looked at it. Then i stretch my hand out to take a bottle. As I took a bottle, the lady at the booth suddenly approached me. The mission could have been compromised. Then she ask me, "Can I help you?"
At this moment, I knew I had to react. I had to. Experience in this line has prepared me for any surprises. I had to allay the suspicion. I looked at the brochure on my hand, looked through it and ask, "I was looking through this brochure and was wondering, what is this U town about?"
Well, I know it was a chessy question to ask. Almost as cheesy as "Am I dead, Angel? Cause this must be heaven!" But with my charm, I sure pulled it off. Of course, with that done, now I have to put up with her explanation which "frankly, my dear, I don't give a damn", now, go make me a sandwich. Actually I do give a damn, because a friend was asking me to apply for U town, I just wanted to use this quote from the 1939 film "gone with the wind".
But after hearing her explanation, well, I kind of didn't want to stay in U Town. Sounds like too much trouble, esp for a year 3 student who is going to graduate in 1 year. I had to make my leave, but she looked too enthusiatic in answering my questions to want me to leave. Damn my handsome looks, it just bring the girls to the yard and now they don't want me to go.
The fortunately, some smart alec girl beside me started to ask a smart alec question, "So if I do modules here, it will induce higher level thinking, right?". Why the hell do you want to take a difficult modules to stress yourself? its not like normal NUS modules wouldn't kill you. Look at the gullibility of freshies, I was once like then before, thinking that we can reach the sky, only to realise that the sky expands as fast as galaxies accelerate away from one another. But it created an opening and I took this chance to make my escape. Out of MPSH and back into the car.
Too much typing, too little sleeping, I be sleeping now. BYE BYE.
Location: MPSH X, where I have no idea what is X
ETA: Afternoon 3
My bro went to the NUS open house yesterday and brought back some freebies.
I thought most of it was pretty okay...but there was one goodie that caught my attention.
This one.
I know the bottle looks like brands essence of chicken, but it rather nice, isn't it?
The "I heart Utown" was quite well designed.
But that is not the main allure. Its the candy inside that is very interesting. Every candy has its own unique design. I am actually very impressed with the effort placed into just making one gift.
Well, so when my brother brought it back, I thought "hey, this is pretty cool...so I decided to take one...then another... and another... before I knew it, it was almost finish.
And that was yesterday. So today, as I was going to school to study, I saw some people carrying the Openhouse bag. Then it hit me that the Openhouse was still opened. Then I thought to myself "hey, lets go get some candy...hehe...hehe...BWAHAHAHAHAHAHA".
So I went to MPSH to get some UTOWN CANDY!!!!
I managed to pass through crowds of people disguised as a prospective student, getting goodie bags and acting like a new student. Its not like they would know or care, but who cares...I'm just saying this to build up the tension. Heck would I know where to find it...Then I trusted my senses, It should be where the faculties are...level 2.
As I entered the MPSH on the second floor, what caught my attention was the U Town booth. I knew it had to be there, otherwise where else could it be? So I walked over the booth, lo and behold sat bottles of UTown candy, right smack on the center of the table. I could just walk over and get it, but it would seem like I was just too damn cheapskate.
So I walked over and took a brochure. As a spy, you must always create a decoy. Decoys are crucial for the success and failure of missions, you can always over-plan but you can never under-plan. In a life as a spy, every decision is a life and death matter. If you want the candy, make it look like the candy wants you.
I took and brochure and briefly looked at it. Then i stretch my hand out to take a bottle. As I took a bottle, the lady at the booth suddenly approached me. The mission could have been compromised. Then she ask me, "Can I help you?"
At this moment, I knew I had to react. I had to. Experience in this line has prepared me for any surprises. I had to allay the suspicion. I looked at the brochure on my hand, looked through it and ask, "I was looking through this brochure and was wondering, what is this U town about?"
Well, I know it was a chessy question to ask. Almost as cheesy as "Am I dead, Angel? Cause this must be heaven!" But with my charm, I sure pulled it off. Of course, with that done, now I have to put up with her explanation which "frankly, my dear, I don't give a damn", now, go make me a sandwich. Actually I do give a damn, because a friend was asking me to apply for U town, I just wanted to use this quote from the 1939 film "gone with the wind".
But after hearing her explanation, well, I kind of didn't want to stay in U Town. Sounds like too much trouble, esp for a year 3 student who is going to graduate in 1 year. I had to make my leave, but she looked too enthusiatic in answering my questions to want me to leave. Damn my handsome looks, it just bring the girls to the yard and now they don't want me to go.
The fortunately, some smart alec girl beside me started to ask a smart alec question, "So if I do modules here, it will induce higher level thinking, right?". Why the hell do you want to take a difficult modules to stress yourself? its not like normal NUS modules wouldn't kill you. Look at the gullibility of freshies, I was once like then before, thinking that we can reach the sky, only to realise that the sky expands as fast as galaxies accelerate away from one another. But it created an opening and I took this chance to make my escape. Out of MPSH and back into the car.
Too much typing, too little sleeping, I be sleeping now. BYE BYE.
Thursday, February 24, 2011
This is just this wisdom to this
Its from the end of the second sequel of Lord of the Rings.
Sam's speech.
The one that really mattered.
Frodo: I can't do this, Sam.
Sam: I know. It's all wrong. By rights we shouldn't even be here. But we are. It's like in the great stories, Mr. Frodo. The ones that really mattered. Full of darkness and danger, they were. And sometimes you didn't want to know the end. Because how could the end be happy? How could the world go back to the way it was when so much bad had happened? But in the end, it's only a passing thing, this shadow. Even darkness must pass. A new day will come. And when the sun shines it will shine out the clearer. Those were the stories that stayed with you. That meant something, even if you were too small to understand why. But I think, Mr. Frodo, I do understand. I know now. Folk in those stories had lots of chances of turning back, only they didn't. They kept going. Because they were holding on to something.
Frodo: What are we holding onto, Sam?
Sam: That there's some good in this world, Mr. Frodo... and it's worth fighting for.
Sam's speech.
The one that really mattered.
Frodo: I can't do this, Sam.
Sam: I know. It's all wrong. By rights we shouldn't even be here. But we are. It's like in the great stories, Mr. Frodo. The ones that really mattered. Full of darkness and danger, they were. And sometimes you didn't want to know the end. Because how could the end be happy? How could the world go back to the way it was when so much bad had happened? But in the end, it's only a passing thing, this shadow. Even darkness must pass. A new day will come. And when the sun shines it will shine out the clearer. Those were the stories that stayed with you. That meant something, even if you were too small to understand why. But I think, Mr. Frodo, I do understand. I know now. Folk in those stories had lots of chances of turning back, only they didn't. They kept going. Because they were holding on to something.
Frodo: What are we holding onto, Sam?
Sam: That there's some good in this world, Mr. Frodo... and it's worth fighting for.
Wednesday, February 9, 2011
Its either this or that.
Do you know what so good about urgent problems that cries out for your attention, which if you really think about it, is a small problem which would not matter when you look back at it 10 years later?
It keeps your mind away from big problems which there is no apparent solution to.
It keeps your mind away from big problems which there is no apparent solution to.
Sunday, January 23, 2011
Sally Yeah!!!!
I know I spelt her surname wrongly, but I know you guys are just waiting for my awesome puns, aren't you?
I know she has many better songs, but I like this so live with it!!!
haha...I don't know why they need to use cartoon for the MTV, its not as if she is any less hot as she was in the 1990s!!! OMG...she is so hot for someone turning 50 this year!!!!
I happened to find this song while finding the song from my previous entry.
I know she has many better songs, but I like this so live with it!!!
haha...I don't know why they need to use cartoon for the MTV, its not as if she is any less hot as she was in the 1990s!!! OMG...she is so hot for someone turning 50 this year!!!!
I happened to find this song while finding the song from my previous entry.
Saturday, January 22, 2011
It seems they have hid you well...
Have you every heard a song, its nice but somehow not nice enough for people to remember it, then somehow, somehow its not on the internet because people couldn't be bothered to upload it?
Then somehow, by some miracle due to the alignment of the stars and 2012, you happened to find it?
I finally found it after so long...
Better go sleep now...tomorrow still got church.
Then somehow, by some miracle due to the alignment of the stars and 2012, you happened to find it?
I finally found it after so long...
Better go sleep now...tomorrow still got church.
Tuesday, January 11, 2011
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