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???
03/06/09 00:22
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#163131 - Be specific please.
Responding to: ???'s previous message
David Prentice said:
Richard,

Andy gave you a link to Luminary ARMs, NXP ARMs are similarly priced.

You get 32k Flash + 8k RAM for £3 in single quantities
or 128k Flash + 32k RAM for £5.35

So you get complete microcontrollers that require NO external support apart from xtals and 3V3 and 1V8 supplies.

Apart from ranting about personal hygiene, surely you must be capable of doing a rough pound / dollar conversion. It is up to you which chips you choose to use, but why feign ignorance ?

If you had really researched ARMs you would be aware of these facts. I also suspect that you know that Farnell is Newark in the US (I think). There will be more competitive prices out there. Andy just quoted a big-name distributor.

David.


Tell me something, David ... Why would I even consider for a moment buying anything from Newark? I was not aware of the link between Newark-U.S. and Farnell-U.K, but last time I ordered something from Newark, it was for standard delivery five days later, and costing $68.05 (an MC68HC705K EVK, which I ordered for a client in order provide it to that client on the following Saturday, meaning the Saturday of the week following the week after the Friday on which it was to be delivered. It was delivered on the Saturday on which I was supposed to deliver it to my client, hence was of no use at all, since I had to get one elsewhere in order to make the delivery, and, while they offered to refund my $68.05, they wouldn't refund the $273 that overnight delivery with Saturday a.m. delivery cost with that carrier. I might have let this slide, once, had it been the first time such a thing happened.

Frankly, I'm not comfortable with European-manufactured ARM's because of that sad experience I had with ATMEL's ARM products. They have, I'm sure, fired those French designers, but they've probably gone to work for someone else, doing the same sort of things. My ARM experience has been primarily with SAMSUNG ARM CPU's, though that's several years old. I do read the trade rags and spam relating to MCU's, and don't believe any of the ones possibly in the right price range offer the performance of which I previously wrote.

The exchange rate pounds to dollars makes the £3 cost $4.28. I was thinking about an earlier exchange rate, closer to $1.97 from a month ago or so, but I'd be really interested to know how this relatively thrifty ARM performs relative to that $6 Maxim/Dallas part, particularly in the context of that data transfer task.

Now, performance is of considerable import, so tell me, does that $4.28 ARM allow you to move 256 bytes on an odd-byte boundary and in bytes in less than 65 microseconds, say, from RAM to external 8-bit port?

Quite frankly, I haven't thoroughly researched ARM-core microcontrollers because I'm not in need of them right now.

When the need arises, I'll probably do a through trade study. In the meantime, however, I'll wait for something to jump out at me. I have nothing against ARM, but I have no reason to run a trade study until I have an application for a new MCU. Every time someone comes along wanting to program a microcontroller in 'C', I tell 'em to use an ARM. I've amply explained why I don't want to do that myself ... yet.
RE










List of 76 messages in thread
TopicAuthorDate
NXP P89LPC936 Auxilary RAM            01/01/70 00:00      
   Compiler Cannot Save the Day At Runtime            01/01/70 00:00      
      I found it.....            01/01/70 00:00      
         Incorrect!            01/01/70 00:00      
            To be fair,...            01/01/70 00:00      
               Its good info to know...            01/01/70 00:00      
   how is it done in C?            01/01/70 00:00      
   Maybe you should try doing it ASM!            01/01/70 00:00      
      You should start a new thread on that!            01/01/70 00:00      
      Not in this case!            01/01/70 00:00      
         A compiler should support ALL MCU features ...            01/01/70 00:00      
            A compiler should translate the language            01/01/70 00:00      
               Still C - just not strict.            01/01/70 00:00      
            I didn't say that!            01/01/70 00:00      
               It is not that clean and clear            01/01/70 00:00      
                  Deviants are deviant            01/01/70 00:00      
                     Keil and SDCC need no macros ...            01/01/70 00:00      
                        Are you sure?            01/01/70 00:00      
                     That's probably correct, but ...            01/01/70 00:00      
                        A C compiler can map the hardware quite well            01/01/70 00:00      
                           compiler vendors are looking at the new processors            01/01/70 00:00      
                              I once mentioned that ...            01/01/70 00:00      
                           It's not what I'd choose, but it is a matter of perefernce            01/01/70 00:00      
                              As flash gets bigger, the code steps do too.            01/01/70 00:00      
                              Still not needed for other architectures            01/01/70 00:00      
                                 We will have to agree to disagree ... I guess            01/01/70 00:00      
                                    Which single-clocker is cheaper than an ARM?            01/01/70 00:00      
                                       RE: Which single-clocker is cheaper than an ARM?            01/01/70 00:00      
                                       differs considerably from the classic microcontroller?            01/01/70 00:00      
                                       Horses for courses            01/01/70 00:00      
                                          Always start each project by scanning the market            01/01/70 00:00      
                                             On that we can agree            01/01/70 00:00      
                                          Maybe, but what are they comparing?            01/01/70 00:00      
                                             Did you actually look?            01/01/70 00:00      
                                                Yes, I did.            01/01/70 00:00      
                                       it's a tradeoff            01/01/70 00:00      
                                          Is it 2006 already?            01/01/70 00:00      
                                             Really?            01/01/70 00:00      
                                                that's outright silly            01/01/70 00:00      
                                                   Maybe ... which is why it is not yet the case            01/01/70 00:00      
                                                      the eyes of the beholder            01/01/70 00:00      
                                                         Look at it from another viewpoint for a moment            01/01/70 00:00      
                                          RE: I'm not the one to ask about IC prices            01/01/70 00:00      
                                             doesn't mean I'm totally in the dark            01/01/70 00:00      
                                                Richard Erlacher has left the planet            01/01/70 00:00      
                                                   Maybe Andy's the one who's lost            01/01/70 00:00      
                                                      I cannot believe you even looked at ARM            01/01/70 00:00      
                                                         It's all relative            01/01/70 00:00      
                                                            Price doesn't directly follow processor size            01/01/70 00:00      
                                                            What about performance?            01/01/70 00:00      
                                                         Be specific please.            01/01/70 00:00      
                                                            You can use your own supplier            01/01/70 00:00      
                                                               Your test simulates as 41.04us            01/01/70 00:00      
                                                                  RE: ARM compiles do not like byte-addressing            01/01/70 00:00      
                                                                     A typo on my part            01/01/70 00:00      
                                                                        Case of full unroll            01/01/70 00:00      
                                                                           ... and what does THAT ARM MCU cost?            01/01/70 00:00      
                                                                              WHO CARES            01/01/70 00:00      
                                                                                 Absolutely true!            01/01/70 00:00      
                                                                              $5 or lower            01/01/70 00:00      
                                                                                 My Simulation times were wrong.            01/01/70 00:00      
                                                                                    67% of your loop was your loop            01/01/70 00:00      
                                                                                    re-written the loop in C            01/01/70 00:00      
                                                                                       Try without loop counter            01/01/70 00:00      
                                                                                          You're right!            01/01/70 00:00      
                                                                                             Similar trick with ARM7 would require 66.67MHz            01/01/70 00:00      
                                                                                             60ns with no store instruction.            01/01/70 00:00      
                                                                                                25% speedup            01/01/70 00:00      
                                                                                                   Actually, I found the for loop faster.            01/01/70 00:00      
                                                                                                      Compiler setting?            01/01/70 00:00      
                                                                                                         I made NO optimisation            01/01/70 00:00      
                                                                                                            Avoid variable aliasing if you like high optimization levels            01/01/70 00:00      
                                                                                                               The RealView compiler is very competent            01/01/70 00:00      
                                                                                                                  Yes, caching            01/01/70 00:00      
                                                                                                                  Yes, caching            01/01/70 00:00      
                                                                                                It's much easier with the 8-bit single-clocker            01/01/70 00:00      

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