Memory for XC167

You evidently are of the school "I like this processor, I WILL use it and MAKE it do what I want".

Not at all, I have no idea if the XC167 processor is the right choice for their application and neither do you. We just don't have enough information to say. The arrogance of you making statements like "ONCE MORE if you need 12Mbyte, you have chosen the wrong processor" without knowing anything else about their system is getting very old.

If you need 12MB of code, you are either multitasking (bad choice of processor) or having such a mess that you are, indeed in big doo-doo.

Have you used this processor? Its interrupt controller makes priority based preemptive multitasking a breeze using the timer module. No kernel needed. This statement leads me to believe you know nothing about the capabilities of the processor.

if you have a problem with me questioning it why do you even read a forum?

I read this forum because I learn a lot from it. It's a shame that people like you have to second guess every design that does not fit the mold that you are used to. Questioning something is one thing, but constantly assuming that no one else can make a right choice unless it passes your litmus test is what I find annoying.

I am done responding to this thread, if you cannot see my point by now it is pointless to continue.

-Walt

You evidently are of the school "I like this processor, I WILL use it and MAKE it do what I want".

Not at all, I have no idea if the XC167 processor is the right choice for their application and neither do you. We just don't have enough information to say. The arrogance of you making statements like "ONCE MORE if you need 12Mbyte, you have chosen the wrong processor" without knowing anything else about their system is getting very old.

If you need 12MB of code, you are either multitasking (bad choice of processor) or having such a mess that you are, indeed in big doo-doo.

Have you used this processor? Its interrupt controller makes priority based preemptive multitasking a breeze using the timer module. No kernel needed. This statement leads me to believe you know nothing about the capabilities of the processor.

if you have a problem with me questioning it why do you even read a forum?

I read this forum because I learn a lot from it. It's a shame that people like you have to second guess every design that does not fit the mold that you are used to. Questioning something is one thing, but constantly assuming that no one else can make a right choice unless it passes your litmus test is what I find annoying.

I am done responding to this thread, if you cannot see my point by now it is pointless to continue.

-Walt

I refer to my earlier post about managing software engineers... The original question was about memory ICs for a 16 bit controller? I recently used a 128kx32 SRAM from IDT(can be used as x16), you might check their catalog. I too have a hat that says hardware on it and I follow the general rule of laying out the PCB to provide all the memory the CPU can use and then populating during assembly as desired. That is unless the application specifically calls for less than the maximum( say rev3 going to production..)
Good luck.

Not at all, I have no idea if the XC167 processor is the right choice for their application and neither do you. We just don't have enough information to say. The arrogance of you making statements like "ONCE MORE if you need 12Mbyte, you have chosen the wrong processor" without knowing anything else about their system is getting very old.

If me questioning the wisdom of 12 MB with the amount of information provided is arrogant, then your statement it is wise is equally arrogant.

You call it arrogance, I call it questioning the wisdom. If the OP not someone that think I may be wrong convince me that what I post does not match a given app I will gladly retract.

If you read this thread, you will see that I constantly ask "how much code memory" and get no answer so, it could be that a board without code memory is being constructed and I will suspect so till the OP not some do-gooder convince me otherwise.

Years ago, I posted things like "I want to make sure ... It could be ... I think" and in many cases the result was that at a later time the same poster posted "it does not work because"

Thus I will much rather have you (who may know the uC vert well) get mad at me for being blunt that lead someone astray with vague posts.

If you have a problem with me stating my opinions, I suggest you state your opinions on the subject of the thread rather than your opinion of me.

Erik

"It's a shame that people like you have to second guess every design that does not fit the mold that you are used to. Questioning something is one thing, but constantly assuming that no one else can make a right choice unless it passes your litmus test is what I find annoying."

I couldn't agree more with this.

So Erik, what's the upper limit on RAM for this processor? What's the maximum latency before 'real time' becomes 'real enough time'?

So Erik, what's the upper limit on RAM for this processor? What's the maximum latency before 'real time' becomes 'real enough time'?
1) I think you get one thing wrong "real enough time" is worse than real time. It is an exprtession invented by the URTOS developers to excuse the sluggedness of their creations. The maximim latency is waht the developer know (s)he can live with, NOT what some URTOS developer has decided.

2) the upper limit for any processor is "what you need"

Now to answer what you really ask
I question everything that is not "typical" unless it is qualified. Not becuase it does not "fit my mold" but because - as seen in the C to asm thread where you had to question an excellent suggestion from Andy - that nobody knows what the app is when the OP does not state so.

Thus if it is "unusual" and no reason is given I try to provoke an answer. Due to your cuddeling no answer has yet come forth from the OP in this thread.

I find it wrong to let someone trundle along and make a board with 12M of RAM if all they need is a few hundered k. Maybe it is your philosophy that if someone want to commit suicide you should give them a gun, that is not mine.

Erik

"I think you get one thing wrong "real enough time" is worse than real time."

No. I asked you what you think the maximum latency is before 'real time' becomes what you call 'real enough time'. In other words, how slow does it have to be, in your opinion, before it is no longer real time.

"The maximim latency is waht the developer know (s)he can live with"

And there you are - it depends on the application.

"the upper limit for any processor is "what you need""

I'm glad you can see that - it it 'what you need' rather that 'what Erik thinks it should be'.

"Thus if it is "unusual" and no reason is given I try to provoke an answer."

No you don't - you just state that the poster is wrong. Take a look at what you said in this thread:

"if you need 12Mbyte, I think you are in deep doo-doo"

Without knowing anything about the application you've just stated that 12Mb of RAM is wrong.

"Due to your cuddeling no answer has yet come forth from the OP in this thread."

I've no idea what 'cuddeling' is, and I'm unable to see how you can know that whatever it is has affected whether the OP chooses to answer your question.

"I find it wrong to let someone trundle along and make a board with 12M of RAM if all they need is a few hundered k. Maybe it is your philosophy that if someone want to commit suicide you should give them a gun, that is not mine."

The guy has stated that 12Mb of memory is what he's been told to provide. Why do you insist on badgering him to justify this? The reason is that you just assume, as usual, that (quoting Walt) if things don't pass your personal litmus test they must be wrong.

"Thus if it is "unusual" and no reason is given I try to provoke an answer."

No you don't - you just state that the poster is wrong.
If you have a better way to provoke an answer, I would like to know it.

The guy has stated that 12Mb of memory is what he's been told to provide If "I have 12MB of external memory area" is being "told to provide", then the english language has changed.

"Due to your cuddeling no answer has yet come forth from the OP in this thread."

I've no idea what 'cuddeling' is, and I'm unable to see how you can know that whatever it is has affected whether the OP chooses to answer your question.
It sure has, his "answer" is "You guys are hilarious......LOL" instead of "I need 12 M because". re "cuddeling": when I try to make the OP state a why, you always come in and post "there is no reason to tell us why, we will give help you go anywhere you want without any concern for whether it is the right path.
Again, If someone ask for a gun, I check for a potential suicide, you provide the gun.

You do your thing, I do mine but PLEASE stay away from comments about my persona, if you have something techincal to add, by all means do.

Erik

To all:
I am sorry that when Stefan attacked my person, I responded the same way, I should not have done that.

"If you have a better way to provoke an answer, I would like to know it."

You could try the normal method - asking a polite question?

"If "I have 12MB of external memory area" is being "told to provide", then the english language has changed."

If you were to read his other posts all would be revealed:

"I am a Hardware Engineer being given requirements by software as far as how much memory."

"It sure has, his "answer" is "You guys are hilarious......LOL" instead of "I need 12 M because"."

You'll notice, however, that he made that comment before I entered into this thread. Do you not realise it's a reaction to *your* badgering?

"re "cuddeling": when I try to make the OP state a why, you always come in and post "there is no reason to tell us why, we will give help you go anywhere you want without any concern for whether it is the right path."

No, I'm just trying to achieve some sort of balance where posters are given some credit for having a clue, and opinions stated as though they were facts are not allowed to overwhelm the forum.

You still haven't explained what 'cuddeling' means.

"if you have something techincal to add, by all means do"

It's pointless - you'll defend an untenable position for a while, then you simply stop responding to points that you've been picked up on.

" I am sorry that when Stefan attacked my person, I responded the same way, I should not have done that."

I didn't notice a personal attack?

It's pointless - you'll defend an untenable position for a while, then you simply stop responding to points that you've been picked up on.

" I am sorry that when Stefan attacked my person, I responded the same way, I should not have done that."

I didn't notice a personal attack?

"It's pointless - you'll ....", If the above is not a "personal attack" pray tell what it is, I see nothing related to a technical problem.

Anyhow I will say no more since answering any of the above would be answering "comments on the person rather than the technical issue" with "comments on the person rather than the technical issue" which has no place in a technical forum.

As to the original issue, I still doubt that 12M is the right size, but that got lost in the "comments on the person rather than the technical issue"

Erik

Thanks William, I'll check it out..........That's all I was looking for.........And yes, I have been asked to provide a design for the maximum amount of memory in the case that we need it. Right now software is only using 2M.

Mike

well, it seems that your request for SRAM manufacturers got lost in the fray, ISSI has up to 512k*16 see http://www.issi.com/index.html >product search >sram >asynch.

You will need an awful lot of chips to populate 12M with 512k chips, but that may be what you have to do. Do remember that the code in this type of application "typically" reside in flash, there you can get much more on a chip for less money (I use SST, they have a 1000 times faster erase than most). Ask those programmers, that evidently do not tell you much, how they want the memory to be divided RAM/Flash

Erik

Yeah I'm starting to get a headache over this much memory.......Apparently the software engineer was told he may need upto 2MB just for fonts for multiple languages (Korean type fonts?). He wants all of it there for development though.
Now I have a question based on your experience using this processor. Basically I'm not far enough along to know how fast you can actually access memory, i.e. how many instruction cycles? Is fast sram (10ns) much faster than standard sram with a 70ns response time? The XC167 is only 40Mhz. I know the memory itself is much faster, but is there really a big difference in this application?

Im considering using Psuedo SRAM.......I know you have an opinion, dont be shy......LOL

Thanks........that 512kb x 16 is fast too.........this helps

""It's pointless - you'll defend an untenable position for a while, then you simply stop responding to points that you've been picked up on.", If the above is not a "personal attack" pray tell what it is, I see nothing related to a technical problem."

How you can misconstrue that as a personal attack is beyond me. It was what has turned out to be a perfectly accurate prediction of your response based on your posting history. The fact that it contained no technical content does *not* make it a personal attack.

What it does express, however, is the futility of attempting to engage you in a technical discussion due to your refusal to even consider the possibility that your 'one size fits all' opinions are not universal truths.

"As to the original issue, I still doubt that 12M is the right size"

As usual, based on exactly zero knowledge of the application.

"but that got lost in the "comments on the person rather than the technical issue"

I don't know anything about your 'person' other than what you write on this forum. Anything you post here is open to debate - that's what a forum is for. If you post your baseless opinions as facts you'd better expect me to disagree with them. If that hurts your feelings, well, too bad.

Yeah I'm starting to get a headache over this much memory.......Apparently the software engineer was told he may need upto 2MB just for fonts for multiple languages (Korean type fonts?). He wants all of it there for development though.
RE fonts; I have yet to see an app with fonts in SRAM, I have seen a plethora of apps with fonts in Flash. I have - among several others - done a limited Japanese which took about 400k.

Now I have a question based on your experience using this processor. Basically I'm not far enough along to know how fast you can actually access memory, i.e. how many instruction cycles?
I'm sorry, but here you will need to refer to the data sheet, so many factors influence this.

Is fast sram (10ns) much faster than standard sram with a 70ns response time?
Well, I'll take a guess that it is 7 times faster :)

I know the memory itself is much faster, but is there really a big difference in this application? I do not recall if the 167 is one of the chips with a software programmable memory timing, if it is this will be a need vs cost decision

Get at this "programmer"s butt and get it clear what (s)he need in flash (program, fonts and other permanent storage) and how much in SRAM. I would not be surprised if you end up with just one SRAM chip

Erik

PS in Flash you can get much more memory per chip than with SRAM (unless someone know about some chips I have not heard about)

Mike,

I'm sorry your thread has been hijacked. I'd love to help but I'm not familiar with the XC167. Given that you are just starting out with microcontroller design I'd suggest that you spend a couple (more) days studying the datasheet and application notes for the device, all should become clear. I did have a quick look at the documentation for this part available on Keil's website and it looks pretty comprehensive.