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AVR MICRO VS PIC MICRO |
Posted: Fri Sep 03, 2004 5:09 am |
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pic vs avr:
for compare pic & avr i select the two micro of each company that are the same level(not compare atmega series
with 16fxxx series)
i select the ATmege128L & 18F8720.both of them is the max powerfull 8 bit micro for each company.(untill now)
the benefit of avr:
1.atmege128l have 8 mips speed at 8mhz & atmega128 have 16 mips speed at 16mhz but the 18f8720 only up
to 10 mips at 10mhz with pLL.
2.the atmega128 have 133 instructions & pic have 75 instructions so the c code for avr is a little optimized
than pic.
3.avr have 32 general purpose working register but pic don't have.
4.avr have 4k eeprom but pic have 1k eeprom.the most important thing that is both of them have 128kb flash
& 4k ram.
THE BENEFIT OF PIC:
1.pic have 8*8 hardware multiplier with single cycle but avr have this but with 2 cycle.
2.pic can address external memory up to 2 Mbytes(2000kbytes). but avr up to 64kbytes.
3.18f8720 have two 16 & two 8 bit timer with one 8/16 bit timer but aver only have two 16 & two 8 bit timer.
4.pic have 16 channel AD with time conversion of 3.2 to 12 us but avr have 8 AD with time conversion of 13 to 256 us.
5.pic have internal eeprom with about 4.6 ms for write time but avr is 8.5 us.
6.pic have Parallel Slave Port data.but avr don't.
7.pic micro have nanowatt techology but avr don't.
8.idle mode for pic is 5.8 ua but avr is 350 us.sleep mode for pic is 0.1 ua for avr <1 ua.
9.100,000 erase/write for flash & 1,000,000 erase/write for eeprom with >40 years retention for pic.
10,000 erase/write for flash & 100,000 erase/write for eeprom with >10 years retention for avr.
10.pic is alittle cheaper than avr.
11.pic have better datasheep than avr & have a good support.
12.oprating voltages for pic is 2 - 5.5 v .for avr ic's without "L" is 4.5 - 5.5 v & with "L" is 2.7 - 5.5 v.
13.pic micros are up to 80 pin but avr up to 64 pin.
14.pic have more current sink/source for I/O about 25mA.
15.pic support ECAN 2.0B with low cost.
here is some of the diffrents of pic & avr.
I am gold to write your idea about which of them is better. |
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valemike Guest
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Posted: Fri Sep 03, 2004 6:34 am |
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I figure a lot of people converted from the 8051 or 6805 to the PIC several years ago, myself included.
Even when a competitor comes up with a so-called better chip (e.g. ARM7, newer AVRs, etc.), there is always a new PIC device that can compete to fulfill our requirements.
They were at the right place at the right time. At such a better price than the 6805/68Hc11 back in the mid-90s, it seems Microchip established its good reputation the past decade and thus its foothold today.
I remember as a college intern in the mid-90s, microchip would have small seminars of only a dozen people or so people that can fit at a distributor's conference room. That's not the case anymore. Now they need hotel ballrooms for their seminars.
So when Atmel releases a chip which can outperform the PIC i'm using, or when Cypress comes out with their configurable system on chip micro, or when Maxim claims to have a supercharged 8051, I would rather find the right PIC, not spend on any new development equipment, and crank out two PIC projects in the time it would take to learn another micro. Time and money is of the essence here. |
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bdavis
Joined: 31 May 2004 Posts: 86 Location: Colorado Springs, CO
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Posted: Fri Sep 03, 2004 7:10 am |
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You didn't mention compilers in your comparison...
I thought Atmel had a free C compiler, but on the other hand the PIC has several to choose from if you want to pay bucks. The compiler (lack of bugs, and how many features it has) is important to me - over 64K of assembler takes too long to write, and debug.
I'll stay with microchip due to their excellent support, and they have plenty of app notes and other information. When the pics came out, I asked Microchip how to program them - they gave me all the detailed information even though I wasn't a big OEM. That was back when they didn't have flash or C compilers and you programmed via a parallel programmer. I attended some of their very inexpensive seminars (something like $25 if I remember correctly) and used the free MPLab using assembler until recently switching to CCS (for the 18FXXX). I'll stay with microchip - the learning curve on another micro is another thing to keep in mind too. |
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treitmey
Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA
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Posted: Fri Sep 03, 2004 10:27 am |
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I agree, I wouldn't want to learn a new uP at this point.
love the typo
"datasheep" |
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TSchultz
Joined: 08 Sep 2003 Posts: 66 Location: Toronto, Canada
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Posted: Sat Sep 04, 2004 5:03 pm |
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I have to agree that the PIC platform is very good!
I have been working at a company that has standardized on the Atmel AVR chips, and although there are some things I like about the family, there are many I do not.
I still use the PIC's for my own projects, and the AVR's for the companies.
My other processor of choice is the TI MSP430, but that is whole other subject.
It is diffucult to say one is "better" than the other. However after using PICs all the way from the eary days of only the PIC16C54 and 55, I do prefer the PIC architecture.
Having a free GNU GCC compiler availlable does make the AVR attractive to people wanting to take a look. The GCC compiler does a fairly good job, but lacks in some areas because it not "aware" of the separate memory spaces used in the parts. A real comparison is not an easy task.
But one thing I must say for the AVR, the fuse bits can be programmed and erased over the entire voltage range. This is not true for the PIC's. This little issue bit me on one project last year and not I design so I can isolate the power and programming voltage to the PIC from the resy of the board. The PIC needs >=4.5VDC to support reliable fuse erase and program. |
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Trampas
Joined: 04 Sep 2004 Posts: 89 Location: NC
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Posted: Sun Sep 05, 2004 8:07 am |
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Personally I have not used the AVR or the 8051s. I have used TI DSPs and will say they rock!
TI last year came out with the 28xx series of DSPs, by the way DSP means that it is a microcontroller with a multiply accumulate instruction. Anyway this DSP was design to be used with the C compiler thus it has hardware to support the compiler, like stacks and such. Last year when I had such a headache trying get the 18F8720 to work I redesigned my project to use a F2812 and will say that it is a dream to work with, especially compared to the PICs.
The compiler is very stable, the JTAG interface blows away any ISP! The compiler and IDE was $495, the JTAG emulator/adpater was expensive, around $1500.
[url=http://dspvillage.ti.com/docs/catalog/generation/overview.jhtml?templateId=5143&path=templatedata/cm/dspovw/data/c2000_ovw]
TMS320F2812[/url] vs dsPIC30F6014
Bits: 32 vs 16
MIPS: 150 vs 30
Cost: $16.47 vs $16.05
RAM: 36k vs 8k (bytes)
FLASH: 256k vs 144k (bytes)
EEPROM: 0 vs 4k (bytes)
ADC: 16x12bits vs 16x12bits
The only problem with the F2812 is that it is a 3.3V only part, actually it uses dual power, 1.8V core and 3.3V IO. Thus if you need a 5V IO then this part is not for you. Also TI will be releasing a $5 part in the 28xx family this spring. Actually the only reason I use the PIC is for the 5V operation.
As far as moving from the PIC to the F2812, you will find it is as simple, the peripherials configurations are simular, the interrupts use enable and flag bits just like the PICs. Thus after you play with a real processor you will start wondering how the PICs survive.
Also I am not sure about power comparisions between the dsPIC and the F2812, as it depends on the peripherials are used and the clock speed, etc. I think the F2812 may be higher current, but I am not sure. I do know that the dsPIC gets really really hot running 30MIPS and alot of people have put fans on them! While I run my F2812 at 120MIPS and do not notice any heat. Of course if power is a concern I would not use the F2812 and instead look at other TI parts, like the 5000 series DSPs.
The point I am trying to make is that do not limit your hobbies to just PIC, AVR, 8051s, etc. Try looking at some real high end parts like the F2812, they are not that much more expensive than a PIC and the performance will make you wonder why you ever worried about code optimizations. At 150MIPS and 32bits the F2812 is like have the performance of a PC on an embedded board.
Like I said even though the processor is great, there are some things a PIC is a better fit for and I still use the PICs, but I will still complain about it too.
Trampas |
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pat
Joined: 07 Sep 2003 Posts: 40 Location: Adelaide, Australia
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Posted: Sun Sep 05, 2004 7:07 pm |
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This is a really interesting thread as I've been wanting to have another more powerful processor in my development arsenal. I thought the 18F would be the logical choice, but when you look around, there is some real competition for the PIC.
I haven't used a Zilog, but the Z8 Encore series look good, and there is a free C compiler available developed by Zilog.
http://www.zilog.com/products/partdetails.asp?id=Z8F64200100KIT
Has anybody else used the Zilog chips?
I was also looking at the TI MSP430 series, and the Atmel AVR mega range.
Perhaps even the Rabbit semiconductor modules might be the go, again has a free C compiler (Dynamic C) developed by the manufacturer.
http://www.rabbitsemiconductor.com/products/rcm2300/index.shtml
Wouldn't it be nice to use a C compiler developed by the manufacturer that was very close to bug free! |
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Mark
Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA
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Posted: Sun Sep 05, 2004 8:46 pm |
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Quote: | Wouldn't it be nice to use a C compiler developed by the manufacturer that was very close to bug free! |
Keep in mind that companies whose soul purpose is to create development tools usually do a pretty good job. Don't expect a semiconductor company to create a great piece of software. Just because they made the micro doesn't mean they would be the best to create a compiler. |
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Trampas
Joined: 04 Sep 2004 Posts: 89 Location: NC
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Posted: Mon Sep 06, 2004 5:56 am |
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I know I have been using the TI compiler and have had one bug fix in the year and a half since they first released the chip and compiler.
I think that a silicon company can make a good compiler, however they need to know they are in that business. For example TI has been doing compilers for years and years. Microchip is relativly new in the compiler market and their compiler is ok but not nearly as nice as TIs.
When looking for a compiler a good question to ask a compiler company is how they test the compiler. For example do they have regression testing. Also ask them if they have a bug tracking system and if it is open to customers.
Trampas |
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Mark
Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA
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Posted: Mon Sep 06, 2004 6:30 am |
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I can say that I have have only found a couple of errors in some asm code for the C18 compiler. It was a breeze to fix and haven't found any problems with the core of the compiler. CCS's had major bugs that caused all sorts of headaches which eventually caused me to buy the C18. |
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Trampas
Joined: 04 Sep 2004 Posts: 89 Location: NC
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Posted: Mon Sep 06, 2004 6:37 am |
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Mark,
A local FAE was telling me about his customers who use PIC processors. He said that most start with CCS, then purchase the C18 or HiTech and then finally end up using the IAR compiler.
I own a copy of the C18 as well and find that the C18 is OK I do like the dsPIC compiler (C30) a bit better. The C30 has the printf routines and also handles interrupts a bit better. However the C30 is absoultly full of bugs.
I was trying to do a simple project for the C30 design contest, but the compiler kept breaking. Microchip's tech support would not responde to calls and emails. I finally just gave up. They may have fixed some of the bugs by now, but Microchip has not been doing a great job of keeping me as a customer.
Trampas |
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xpercad
Joined: 27 Jun 2004 Posts: 12 Location: MÉXICO
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Mark
Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA
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Posted: Mon Sep 06, 2004 2:19 pm |
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Yeah, I'll probably try one in one of our new products. |
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Paul_B
Joined: 08 Sep 2003 Posts: 9 Location: Birmingham, UK
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alternatives |
Posted: Tue Sep 07, 2004 6:17 am |
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Hi all
I have been a big fan of PICs for a couple of years now always using CCS compiler during my projects.
I am glad to see some of you commenting on the alternatives to using PIC's. It has made very interesting reading and tempted me to try an alternative to PIC's to see how different they are. However, my microcontroller programming/ development equipment is purely revolved around PIC's since i have never ventured to the "other side of the fence" so to speak.
Therefore my question is: What is the easiest, cheapest to set up a development environment for. I have heard some of you speak of free C compilers, but what about development boards. Can i produce my own PCB for a development board relatively easy. Do these other micros use a similar method to ICSP/ bootloaders or will i have to buy such equipment as JTAG cables (although some of these can be home made). I know of home made AVR programmers, i am refering to the more powerful chips such as TI, Philips, etc.
All replies appreciated.
Regards
Paul_B |
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dbotkin
Joined: 08 Sep 2003 Posts: 197 Location: Omaha NE USA
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Posted: Tue Sep 07, 2004 10:02 am |
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Comparing top-end products is OK, but what keeps me using PICs is the continued focus on the entire product line. I have yet to find ANY other manufcturer who has kept even close to Microchip in the low end. The 12F675 and now the 12F683 simply cannot be beat, not that I've seen. Dirt cheap, tons of features, and my product will run for months or maybe years on a single CR2032 cell - sleep current is so low it's ridiculous.
Everyone's developing the next super-duper megachip, but no one that I have found has the features and cost across the rest of the product line, which is the territory where I live - the middle of the product families.
Have a great week, folks!
Dale |
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