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smileymicros
PostPosted: Jan 14, 2012 - 04:31 PM
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jhalpin wrote:
We're running a version of linux that was patched for the AT91, and writing drivers can take advantage of special purpose code in the kernel, so it's not nearly as complicated as I thought it would be.
Running a 32-bit chip with Linux isn't more complicated than running an 8-bit chip with a while(1) loop in main()?

Smiley

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clawson
PostPosted: Jan 14, 2012 - 04:50 PM
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Quote:

I tried this in an ARM and failed horribly.

Why is Asm and cycle counting in ARM any more of a problem than doing it in AVR? I cannot see it myself.
Quote:

I have concluded that ARM cannot be cycle counted and coding assembly is going to be a lost art.

Nope still not getting it.

BTW the LPC1769 can do 120MHz not just 70MHz.

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AtomicZombie
PostPosted: Jan 14, 2012 - 05:22 PM
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clawson wrote:
Quote:

I tried this in an ARM and failed horribly.

Why is Asm and cycle counting in ARM any more of a problem than doing it in AVR? I cannot see it myself.
Quote:

I have concluded that ARM cannot be cycle counted and coding assembly is going to be a lost art.

Nope still not getting it.

BTW the LPC1769 can do 120MHz not just 70MHz.


It becomes difficult to impossible to cycle count on an ARM due to the pipeline. There are many good discussions on this, and most end up with the agreement that it is not really feasible.

http://electronics.stackexchange.com/qu ... us-e-g-arm

I managed to do some video but had to resort to PWM or timers, which is severely limiting in the end.

AVR is just awesome for assembly programming whereas ARM assembly seems reserved for the clinically insane hacker. One day I hope to learn it well!

LPC1769 and Cortex M0 are the ones I mess around with.

Brad

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kk6gm
PostPosted: Jan 14, 2012 - 06:04 PM
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Personally I've never needed to look at the ARM core manuals, beyond the few pages that describe the NVIC registers (oh, and the system tick stuff). Maybe the target audience for those are people implementing the cores on their own devices?

And clawson is exactly right, that most of any datasheet/manual is about the peripherals anyway. 98% of the time I look at a datasheet/manual, it's to search out new info for some peripheral, or to look up electrical info or package info.
 
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clawson
PostPosted: Jan 14, 2012 - 06:37 PM
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But the piepline is deterministic isn't it? The only thing that upsets pipelines are when branches are taken but even that behaviour should be deterministic too (if it weren't how could the ARM core execute it!)

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jgmdesign
PostPosted: Jan 14, 2012 - 06:39 PM
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Joined: Apr 20, 2007
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Quote:
I apologize gentlemen, but somebody had to address this white elephant.


You owe no one here an apology. Especially me, I am the first to admit, that I don't use ATMEL exclusively..I use the AVR exclusively, but I do not always use their CPLD because they do not make one bigger than 128 macrocells.

In fact every one of us uses other devices besides Atmel at times. You have to. But unlike Leon we don't come back time and time again and hawk the other guys wares. It is basically rude.

Quote:
It also bugs me that the moderators are too diplomatic to not have done something about this considering that this is an AVR fan site!


I agree, they are beyond polite. A while back they managed to ban a jerkoff that was taking code from the site, posting it on his as his own.

Why Leon continues to get away with it is bullsh**. I used to find him amusing, then just annoying, but I elevated him to a total DB.

Our elders drummed it into us to just ignore DB's like him and they go away. Too bad there is no ointment that can get rid of this DB of a rash. The moderators won't. I probably will get kicked out for saying what has been on other peoples minds for a while.

And to Leon, unless you can provide help, or positive information when someone is talking about ATMEL AVR's

SHUT THE F*** UP!!!!

Jim

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Jim

I have decided that I am no longer going to plan anything in advance. In a court of law this is called Pre-Meditated, and does not look good for the defense.....

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skeeve
PostPosted: Jan 14, 2012 - 07:21 PM
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clawson wrote:
But the piepline is deterministic isn't it? The only thing that upsets pipelines are when branches are taken but even that behaviour should be deterministic too (if it weren't how could the ARM core execute it!)
Is it documented where mere mortals can find it?
Is it simple enough that mere mortals could use it?
Is it consistent between chips?

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abcminiuser
PostPosted: Jan 14, 2012 - 07:33 PM
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Jesus tapdancing christ Leon. Atmel aren't about to go to everyone's house and personally desolder every first revision XMEGA and replace it with a newer version. The latest XMEGAs fix all the old errata, what more do you want?

- Dean Twisted Evil

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jgmdesign
PostPosted: Jan 14, 2012 - 07:36 PM
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Quote:
what more do you want?



For you to jump ship to Micro... Wink
THAT would tilt the earth I am sure

Jim

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Jim

I have decided that I am no longer going to plan anything in advance. In a court of law this is called Pre-Meditated, and does not look good for the defense.....

Timer function not working properly? Check CLKDIV8 Fuse first Wink
 
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leon_heller
PostPosted: Jan 14, 2012 - 07:41 PM
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What has caused all the complaints about the Xmega has been the length of time that has elapsed before the bugs were fixed. Why couldn't Atmel fix them earlier?

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abcminiuser
PostPosted: Jan 14, 2012 - 07:47 PM
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Quote:

Why couldn't Atmel fix them earlier?


Look at the silicon revision of the released silicon. The new chips went through an enormous amount of testing to try to prevent you from having any more whining fodder.

- Dean Twisted Evil

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leon_heller
PostPosted: Jan 14, 2012 - 07:53 PM
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I noticed that, they are Rev E.

It's not just me that has complained about the earlier Xmegas, have you seen all the negative comments about them?

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jhalpin
PostPosted: Jan 14, 2012 - 09:10 PM
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Joined: Jul 17, 2010
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smileymicros wrote:
jhalpin wrote:
We're running a version of linux that was patched for the AT91, and writing drivers can take advantage of special purpose code in the kernel, so it's not nearly as complicated as I thought it would be.
Running a 32-bit chip with Linux isn't more complicated than running an 8-bit chip with a while(1) loop in main()?
Smiley


Yes, of course it's more complicated than an AVR. It isn't as complicated as I thought it would be.
 
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clawson
PostPosted: Jan 14, 2012 - 09:20 PM
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Quote:

Running a 32-bit chip with Linux isn't more complicated than running an 8-bit chip with a while(1) loop in main()?

Linux is just an environment (that happens to provide more pre-canned computing services available to the programmer than any other system bar none). It's no real different to, for example, FreeRTOS. I can write a program:
Code:
#include <stdio.h>

int main(void) {
  while(1) {
    printf("Hello world\n");
  }
}

build and run it on a Linux system and it does exactly what it says on the tin (in fact I guess it would do the same in MS-DOS too). In that sense writing a program that runs under Linux is no real different to writing one that runs under Windows or FreeRTOS or whatever other 8 bit "RTOS" you care to mention.

True, in Linux you cannot just say:
Code:
PORTB = 0x55;

but you can say:
Code:
ioctl(link_to_my_PORTB_driver, PORTB, 0x55);

and then have a small piece of kernel code that makes h/w access to PORTB.

This sounds complex - it isn't really.

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abcminiuser
PostPosted: Jan 14, 2012 - 09:50 PM
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Quote:

It's not just me that has complained about the earlier Xmegas, have you seen all the negative comments about them?


Yes I have, and those comments are why we now have fixed versions. I was pointing out the reason for the lengthy delay.

Quote:

For you to jump ship to Micro... Wink
THAT would tilt the earth I am sure


Actually funnily enough I would never work for Microchip, and Leon is the reason why. I considered an offer from NXP before signing on to Atmel, but however irrational it may be I now associate Leon with the Microchip brand and so wouldn't/couldn't take up a job working at Microchip regardless of pay.

- Dean Twisted Evil

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Kartman
PostPosted: Jan 14, 2012 - 10:22 PM
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Joined: Dec 30, 2004
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Location: Melbourne,Australia

Dean, you may rue the day you made that comment. I paid dearly for saying something similar years ago. Company loyalty is good, but things change.

I don't know why you guys are dumping on Leon in this instance. He stated a fact that no one has disproved - brand X sells more chips. We all know ( or should know by now), that Leon is not wedded to any one brand. Seems what is practised here is "brand racism". It probably doesn't happen in other similar forums as people there don't give crap.here there a very few unanswered posts, compare this with some other forums.

Let's face it, how much of the advice that is given here affects Atmels bottom line? Well, apart from the canning of the xmega?

Leon, in order to assuage the ruffled feathers here, maybe refer to the unmentionable company as "brand X". Not sure how we would refer to the other competition, eg TI could be " brand Y", ST as "brand S" and NXP as " brand N", Zilog would be "brand Z" then.
 
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abcminiuser
PostPosted: Jan 14, 2012 - 10:30 PM
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Joined: Jan 23, 2004
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Quote:

Dean, you may rue the day you made that comment. I paid dearly for saying something similar years ago. Company loyalty is good, but things change.


To be clear; I could certainly work for other companies one day, it's just Microchip that I wouldn't work for due to Leon's influence. I'm not narrow minded to the point that I am willing to live and die by Atmel (although I do like Atmel a lot for obvious reasons) but every time I think about Microchip I get a weird repulsive shiver when I think of his posts here. Irrational, but there it is.

Quote:

Leon, in order to assuage the ruffled feathers here, maybe refer to the unmentionable company as "brand X".


I really, really don't want to get into this here again, especially given my time is limited now that I'm working. Leon's behavior here has been ranted about to death by myself and others many times, and while I would love to (and now can) delete his account I would rather save my breath and assist others instead.

- Dean Twisted Evil

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smileymicros
PostPosted: Jan 15, 2012 - 12:54 AM
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Joined: Nov 17, 2004
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Location: Great Smokey Mountains.

I used to be an Atmel fanboy RAH RAH!. Then I realized that nobody at Atmel was a: aware of AVR Freaks, or b: gave a sh**. Long gone are the days of 'My microcontroller can beat up your microcontroller' and promotions such as the AVR Man Super Hero. Replaced by the land of the timid sheep bah bah. So we are forced to put up with obvious trolls that any other self-respecting forum would block. If you guys grow a pair and start acting with reasonable defense of yourselves, I might just pick up the flag again myself. Until then, rah freaking rah.

Smiley

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jgmdesign
PostPosted: Jan 15, 2012 - 04:16 AM
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Joined: Apr 20, 2007
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@Dean,
While it is refreshing to see someone from Atmel show some bollocks for a change, if I were you I would keep a low profile as grandstanding about an ability you now have could be taken in the wrong tense and cause you more grief than it would be worth.

Leon is a DB, and as noted he is a rash that won't go away. I for one am going to do my best not to allow the DB to get under my skin. The rest of us should just IGNORE the DB and keep to the topic in the thread.

As for the administrative staff whomever they may be, along with the pair that you have been requested to grow, might I add that you also look into a stick to go with it....OR whenever someone signs up for an account, before the account becomes active a warning of a DB disquised as a cat lurks within.

Every dog has his day. Let's hope the cats 9 lives are up soon as well.

Jim

Edit: I spelled the DB's name wrong....sorry Sad

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Jim

I have decided that I am no longer going to plan anything in advance. In a court of law this is called Pre-Meditated, and does not look good for the defense.....

Timer function not working properly? Check CLKDIV8 Fuse first Wink
 
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Kartman
PostPosted: Jan 15, 2012 - 06:55 AM
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Joined: Dec 30, 2004
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Dean, you mentionedMicrochip! It's now Brand X. This is part of the re-education. Brand X, doesn't it just roll off the tongue and none of the bitterness. the advertising industry figured it out years ago.

Leon, whenever you want to mention the unmentionable, use Brand X. If someone asks what is Brand X, leave it to them to figure out. If someone says Microchip, you respond with Brand X.

All solved guys!
 
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