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Sci.Electronics.Basics -> Which uController to learn?
There are 124 messages in this thread.
You are currently looking at messages 100 to 120.
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Author: John BarrettDate: 13:03 23-03-07
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"Anthony Fremont" <spam-not@nowhere.com> wrote in message
news:1307jeqbvqfpv61@news.supernews.com...
> jasen wrote:
>> On 2007-03-17, bungalow_steve@yahoo.com <bungalow_steve@yahoo.com>
>> wrote:
>>
>>> the AVR series hasen't increased in performance in years (speed, a/d
>>> resolution, DMA, fifo buffers, divide instructions etc).
>>
>> Many of them are doing 20 MIPS now, that wasn't available two years
>> ago, built-in full speed USB is new too,
>
> 20 MIPS, on a MEGA. Those aren't backwards compatible with the tradition
> AVRs are they?
>
>> It's an 8-bit microcontroller it doesn't need that extra stuff ...
>
> Speak for yourself. Since when is A/D resolution not important for an 8
> bitter?
>
AVR32 based 32-bit MCU/DSP
Vectored multiplier co-processor, 32 KB on-chip SRAM, 16 KB instruction and
16 KB data caches, MMU, DMA controller. Peripherals include a 16-bit stereo
audio DAC, 2048x2048 pixel TFT/STN LCD controllers, 480 Mbps USB 2.0 with on
chip transceivers (PHY) and, two 10/100 Ethernet MACs. Serial interfaces
include RS232, USART, I2S, AC97, TWI/I2C, SPI, PS/2 and several synchronous
serial modules (SSC) supporting most serial communication protocols.
sounds like a bit more than an 8-bitter to me !!
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Author: krwDate: 13:09 23-03-07
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In article <BFTMh.81$un.9@trnddc03>, ke5crp1@verizon.net says...
>
> "krw" <krw@att.bizzzz> wrote in message
> news:MPG.206da510f80eb5e298a216@news.individual.net...
> > In article <1307g1itfi6is9d@news.supernews.com>, spam-not@nowhere.com
> > says...
> >> jasen wrote:
> >> > On 2007-03-16, Anthony Fremont <spam-not@nowhere.com> wrote:
> >> >> TT_Man wrote:
> >> >>>> As you said, PIC is king and it is for a reason, they
work.
> >> >>>>
> >> >>> Only if you can get to grips with the appalling op code
set..... OK
> >> >>> if you can program in C , I suppose.I can't/won't
> >> >>
> >> >> I only do assembler on the PIC too. What's wrong with the
op-code
> >> >> set? It's RISC,
> >> >
> >> > no it's not, it has too few registers to qualify.
> >>
> >> By whose definition? It stands for Reduced Instruction Set. 35
> >> instructions is pretty reduced IMO.
> >
> > Actually, it stands for "Reduced Instruction Set Complexity". It
has
> > nothing to do with the number of instructions (PowerPC is certainly
> > RISC, yet has hundreds of instructions in even more varieties),
> > rather the complexity of the instructions. For example, no
> > arithmetic operations on memory are allowed, only load/stores.
> >
> >> >> it has 35 instructions, it's not supposed to be luxurious. It's
> >> >> supposed to be functional and fast....it succeeds.
> >> >
> >> > It always seemed kind of awkward and slow slow to me.
> >>
> >> Compared to what? 10MIPs on a few mA is pretty good in my book.
> >>
> > --
> > Keith
>
> RISC essentially means that EVERY instruction takes ONE clock cycle, so your
> clock speed is your IPS -- CISC chips like the 80x86 take anywhere from
> 4-??? instructions per clock, they internally decode instructions through a
> micro-code rom in the CPU that sequences the internal processing elements of
> the chip through the steps neccessary to perform the instruction -- for
> instance -- a single instruction may read memory, add it to a register, and
> write the result back to memory -- all in one instruction, but across
> multiple clock cycles.
Nope. RISC == "Reduced Instruction Set Complexity". It has nothing
to do with IPS. RISC is a philosophy. IPS is a design trade-off.
The PowerPC *is* a RISC architecture. Some PowerPC implementations
(e.g.. PPC750) tend to be one-cycle through the execution unit (plus
decode, etc) where the Power5 is the same architecture and may be 5
to 15 cycles through the execution unit.
The x86 processors have memory reference arithmetec instructions
(e.g.. ADD R,<memory>, thus CISC (the opposite of RISC). PowerPC has
no like instruction.
> Therefore there are things a CISC chip can do in one ASM instruction that a
> RISC chip cannot do, simply because there is no way to perform the operation
> in a single clock cycle... for instance -- the 80x86 has a single
> instruction memory copy capability for moving data around -- makes things a
> little easier on the compiler developers.
>
It's RISC, not because it can do more than one thing per instruction,
but because it can operate on memory with one instruction. BTW, RISC
compilers are *far* easier to write; one of the reasons RISC was
invented. RISC processors tend to be register rich, since they
cannot operate on memory.
--
Keith
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krw <krw@att.bizzzz> writes:
> BTW, RISC compilers are *far* easier to write;
This is an invalid generalization. Compiler complexity depends on
many factors, and the raw size of the instruction set isn't even near
the top of the list. Specialization is a more key factor, and RISC
chips tend to have more specialized instructions. A CISC chip, for
example, can usually add anything to anything, whereas RISC chips can
only add registers, and sometimes add constants to a register.
The top of the list is usually "customer's requests for unique
functionality".
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Author: linnixDate: 13:36 23-03-07
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On Mar 23, 3:57 am, jasen <j...@free.net.nz> wrote:
> On 2007-03-22, linnix <m...@linnix.info-for.us> wrote:
>
>
>
> > On Mar 22, 1:58 am, jasen <j...@free.net.nz> wrote:
> >> On 2007-03-19, linnix <m...@linnix.info-for.us> wrote:
>
> >> >> Like my current project for instance.
> >> >> It has to "rob" power from something that was never
intended to
> >> >> deliver it.
>
> >> > Or last at long as possible on battery.
>
> >> >> I need to powerdown more than roughly 90% of the time, drawing no
more
> >> >> than a few uA.
> >> >> And not much more than 100uA for the other 10% of the time.
> >> >> Oh, and for that, the clock speed is barely 20kHz (+/- 10%).
>
> >> > I need uA in stand-by. Full speed (Usb or Serial) while connected.
> >> > So, I need it very slow and very fast. For Serial, Avr tops at
19,000
> >> > baud
>
> >> that'd be because you're running such a slow clock.
> >> at only 1.8432 Mhz you can 115200 baud. basically 1/16 your clock.
>
> > No, it won't. At 2 MHz, AVR have lock-ups for 38,400 baud.
>
> "lock ups?"
>
> The attiny2313 "data sheet" suggests it should be capable of 250Kbps
> (asynchronous serial) at 2mhz
>
> With a 2MHz clock 38400 baud isn't really an option on that hardware,
> 35714.3 or 41666.7 are the closest choices.
>
> If you reduce the clock to 1.8432 Mhz (should be a standard size)
> 38400.0 is available (as are the other standard speeds upto 230400)
>
> > My AVR clock toggles between 2 MHz and 32KHz.
>
> Not with the uart running I hope!
>
> >> > and Arm tops at 920,000 baud.
>
> >> yeah, but at what clock speed.
>
> > 20 MHz.
>
> How does it manage that? 920K doesn't divide 20M, is there an internal PLL
> or something?
Yes, an internal PLL at 200 MHz.
>
> Anyway it seems kind of slow :^)
I have to slow it down to talk to the AVR anyway.
>
> Some people bit-bang USB at 1.5Mb/s on 12Mz AVRs. (as a non-interruptable
> foreground task) again the trick is to pick a clock rate that's a
> sufficiently high multiple of the data rate.
>
Unfortunately, they are often conflictings, i.e. USB vs. Serial.
> Bye.
> Jasen
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Author: krwDate: 14:13 23-03-07
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In article <xn4pob3lui.fsf@delorie.com>, dj@delorie.com says...
>
> krw <krw@att.bizzzz> writes:
> > BTW, RISC compilers are *far* easier to write;
>
> This is an invalid generalization. Compiler complexity depends on
> many factors, and the raw size of the instruction set isn't even near
> the top of the list.
I never said it was! Perhaps you'd like to read what I wrote.
RISC <> small_instruction_set was one of my main points.
> Specialization is a more key factor, and RISC
> chips tend to have more specialized instructions.
Nonsense. If anything RISC's instructions are less specialized.
There aren't any string moves to memory, for instance.
> A CISC chip, for
> example, can usually add anything to anything, whereas RISC chips can
> only add registers, and sometimes add constants to a register.
That is pretty much the definition of RISC, so yes... They generally
have LOTSA register though. It's easier scheduling data when you
have lots of places to put it. Register management is more complex
with CISC processors.
> The top of the list is usually "customer's requests for unique
> functionality".
Huh? When does a customer request functionality from a compiler?
--
Keith
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krw <krw@att.bizzzz> writes:
> Huh? When does a customer request functionality from a compiler?
When you write compilers for a living, as I do, and the customer is
the one who created the chip you're targetting. They're usually the
ones who pay for embedded development tools.
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Author: Anthony FremontDate: 15:28 23-03-07
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John Barrett wrote:
> "Anthony Fremont" <spam-not@nowhere.com> wrote in message
>> Speak for yourself. Since when is A/D resolution not important for
>> an 8 bitter?
>>
>
> AVR32 based 32-bit MCU/DSP
> Vectored multiplier co-processor, 32 KB on-chip SRAM, 16 KB
> instruction and 16 KB data caches, MMU, DMA controller. Peripherals
> include a 16-bit stereo audio DAC, 2048x2048 pixel TFT/STN LCD
> controllers, 480 Mbps USB 2.0 with on chip transceivers (PHY) and,
> two 10/100 Ethernet MACs. Serial interfaces include RS232, USART,
> I2S, AC97, TWI/I2C, SPI, PS/2 and several synchronous serial modules
> (SSC) supporting most serial communication protocols.
> sounds like a bit more than an 8-bitter to me !!
Slightly. ;-) Sounds allot like an ARM knockoff. I wonder what the power
dissipation is on that, I'm guessing it's a bit more than my slow,
cumbersome PIC. I bet it costs more than a $1 too. ;-)
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Author: Terran MelconianDate: 15:47 23-03-07
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On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
> 20 MIPS, on a MEGA. Those aren't backwards compatible with the tradition
> AVRs are they?
There's not much difference between them. The most significant is
probably that the mega series has a hardware 8-bit MUL instruction which
takes two clock cycles. I would not say that going from one series to
the other necessitates any more modifications than going between parts
in the same series.
Maybe you were thinking of the AVR32?
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Author: Phil HowardDate: 16:07 23-03-07
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In alt.engineering.electrical Anthony Fremont <spam-not@nowhere.com> wrote:
| jasen wrote:
|> On 2007-03-16, Anthony Fremont <spam-not@nowhere.com> wrote:
|>> TT_Man wrote:
|>>>> As you said, PIC is king and it is for a reason, they work.
|>>>>
|>>> Only if you can get to grips with the appalling op code set..... OK
|>>> if you can program in C , I suppose.I can't/won't
|>>
|>> I only do assembler on the PIC too. What's wrong with the op-code
|>> set? It's RISC,
|>
|> no it's not, it has too few registers to qualify.
|
| By whose definition? It stands for Reduced Instruction Set. 35
| instructions is pretty reduced IMO.
I guess some people thought RISC meant Registers In Surplus Capacity.
|>> it has 35 instructions, it's not supposed to be luxurious. It's
|>> supposed to be functional and fast....it succeeds.
|>
|> It always seemed kind of awkward and slow slow to me.
|
| Compared to what? 10MIPs on a few mA is pretty good in my book.
I like that book.
--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2007-03-23-1503@ipal.net |
|------------------------------------/-------------------------------------|
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Author: jasenDate: 02:34 24-03-07
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On 2007-03-23, linnix <me@linnix.info-for.us> wrote:
>> If you reduce the clock to 1.8432 Mhz (should be a standard size)
>> 38400.0 is available (as are the other standard speeds upto 230400)
>>
>> > My AVR clock toggles between 2 MHz and 32KHz.
>>
>> Not with the uart running I hope!
The 32Khz are you do that using the watchog and prescaler? 128KHz/4 or an
external clock.
It looks like the internal RC can be pulled across an octave in 256 steps
so getting within 0.5% of some multiple of 38400 should be possible.
>> >> > and Arm tops at 920,000 baud.
>>
>> >> yeah, but at what clock speed.
>>
>> > 20 MHz.
>>
>> How does it manage that? 920K doesn't divide 20M, is there an internal PLL
>> or something?
>
> Yes, an internal PLL at 200 MHz.
>
>>
>> Anyway it seems kind of slow :^)
>
> I have to slow it down to talk to the AVR anyway.
>
>>
>> Some people bit-bang USB at 1.5Mb/s on 12Mz AVRs. (as a non-interruptable
>> foreground task) again the trick is to pick a clock rate that's a
>> sufficiently high multiple of the data rate.
>>
>
> Unfortunately, they are often conflictings, i.e. USB vs. Serial.
yeah, it'd need an external clock if it wanted to do serial at standard
rates and bit-bang the usb
someone was saying that the AVRs are standing still while the PICs are
advancing, I'm not seeing that. the ATTiny2313 datasheet has 3 times as many
pages as the AT90S2313, and it seems like it has three times the features too,
that part's been available for a while now but I see they are upgrading
other parts to 20Mhz and I assume the other new 2313 fearures too
still binary and electically compatible with the at90s2313 AIUI.
(except for parallel programming)
--
Bye.
Jasen
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Author: jasenDate: 03:54 24-03-07
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On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
> jasen wrote:
>> On 2007-03-16, Anthony Fremont <spam-not@nowhere.com> wrote:
>>> TT_Man wrote:
>>>>> As you said, PIC is king and it is for a reason, they work.
>>>>>
>>>> Only if you can get to grips with the appalling op code set..... OK
>>>> if you can program in C , I suppose.I can't/won't
>>>
>>> I only do assembler on the PIC too. What's wrong with the op-code
>>> set? It's RISC,
>>
>> no it's not, it has too few registers to qualify.
>
> By whose definition?
Pretty much everyones (with the exception of the PIC fans).
google "what is risc" sometime.
--
Bye.
Jasen
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Author: jasenDate: 05:07 24-03-07
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On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
> jasen wrote:
>> On 2007-03-17, bungalow_steve@yahoo.com <bungalow_steve@yahoo.com>
>> wrote:
>>
>>> the AVR series hasen't increased in performance in years (speed, a/d
>>> resolution, DMA, fifo buffers, divide instructions etc).
>>
>> Many of them are doing 20 MIPS now, that wasn't available two years
>> ago, built-in full speed USB is new too,
>
> 20 MIPS, on a MEGA. Those aren't backwards compatible with the tradition
> AVRs are they?
20 on a ATTiny2313 last year, megas to0 this year, up from 16.
I've only compared the ATTiny2313 and the AT90S2313
Those two certainly appear to be binary compatible in that the newer Tiny
will run the older 90S programs and perform the same.
>> It's an 8-bit microcontroller it doesn't need that extra stuff ...
>
> Speak for yourself. Since when is A/D resolution not important for an 8
> bitter?
how often is 10 bits too few ?
Bye.
Jasen
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Author: LionelDate: 09:05 24-03-07
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On 24 Mar 2007 09:07:41 GMT, jasen <jasen@free.net.nz> wrote:
>On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
>> jasen wrote:
>>> On 2007-03-17, bungalow_steve@yahoo.com <bungalow_steve@yahoo.com>
>>> wrote:
>>>
>>>> the AVR series hasen't increased in performance in years (speed, a/d
>>>> resolution, DMA, fifo buffers, divide instructions etc).
>>>
>>> Many of them are doing 20 MIPS now, that wasn't available two years
>>> ago, built-in full speed USB is new too,
>>
>> 20 MIPS, on a MEGA. Those aren't backwards compatible with the tradition
>> AVRs are they?
>
>20 on a ATTiny2313 last year, megas to0 this year, up from 16.
>
>I've only compared the ATTiny2313 and the AT90S2313
>
>Those two certainly appear to be binary compatible in that the newer Tiny
>will run the older 90S programs and perform the same.
>
>>> It's an 8-bit microcontroller it doesn't need that extra stuff ...
>>
>> Speak for yourself. Since when is A/D resolution not important for an 8
>> bitter?
>
>how often is 10 bits too few ?
Quite often. Photography & audio work, just for two popular examples.
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
\|/ \|/ Perna condita delenda est
---^----^---------------------------------------------------------------
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Author: LostgallifreyanDate: 10:39 24-03-07
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Lionel <usenet@imagenoir.com> wrote in
news:0g8a039nv97085vme4997faf4nhuko1uf0@4ax.com:
>>>> It's an 8-bit microcontroller it doesn't need that extra stuff ...
>>>
>>> Speak for yourself. Since when is A/D resolution not important for
>>> an 8 bitter?
>>
>>how often is 10 bits too few ?
>
> Quite often. Photography & audio work, just for two popular examples.
>
Agreed. SOme tasks like laser scanning might call for a small dedicated
controller, and you'd certainly want 16 bits there, especially if colour
mixing was needed.
Even a small task like lin/log conversion, which many on Usenet advise me
was best solved by code, needs to use 16 bits for accuracy over a decent
range. Unless more tiny micros are made with 16 bit ADC and DAC on board,
people will always be agonising over expensive analog computation IC's. Far
better that we have a small number of cheap standard parts we can learn to
code for. If I knew I could have this, I'd put more effort into learning
it. I don't want to do it with a 40 pin device that needs a diploma to
learn either, I want to do it with a 4 pin IC and some very simple high
level language.
The way things are now, even real experts have argued and floundered over
what best to advise. If more small micros had 16 bit analog I/O built in,
people like me wouldn't even have to ask.
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Author: LostgallifreyanDate: 10:42 24-03-07
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Author: linnixDate: 11:03 24-03-07
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> Unless more tiny micros are made with 16 bit ADC and DAC on board,
> people will always be agonising over expensive analog computation IC's.
If you need 16 bits, the additional chip is the least of your problem.
The noise with D & A circuits on the same board will be so difficult
to deal with, let alone on the same chip.
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Author: LostgallifreyanDate: 11:35 24-03-07
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"linnix" <me@linnix.info-for.us> wrote in
news:1174748606.153653.149590@p15g2000hsd.googlegroups.com:
>> Unless more tiny micros are made with 16 bit ADC and DAC on board,
>> people will always be agonising over expensive analog computation IC's.
>
> If you need 16 bits, the additional chip is the least of your problem.
> The noise with D & A circuits on the same board will be so difficult
> to deal with, let alone on the same chip.
>
>
Good point... Makes me wonder why I was so often told that the problem is
best solved with code. Analog computation doesn't look so expensive, given
the ease of handling the parts and signals.
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Author: Sjouke BurryDate: 18:00 24-03-07
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jasen wrote:
> On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
>> jasen wrote:
>>> On 2007-03-16, Anthony Fremont <spam-not@nowhere.com> wrote:
>>>> TT_Man wrote:
>>>>>> As you said, PIC is king and it is for a reason, they work.
>>>>>>
>>>>> Only if you can get to grips with the appalling op code set..... OK
>>>>> if you can program in C , I suppose.I can't/won't
>>>> I only do assembler on the PIC too. What's wrong with the op-code
>>>> set? It's RISC,
>>> no it's not, it has too few registers to qualify.
>> By whose definition?
>
> Pretty much everyones (with the exception of the PIC fans).
>
> google "what is risc" sometime.
>
>
>
What do you not understand about
"Reduced Instruction Set Computer"?
(A computer with a reduced instruction set???)
A computer with about 30 instructions can be called
a risc computer,as compared to the x86 group with about 500.
Now if you want to claim that name for something else,
you better explain that, because I think a lot of people
dont agree with you.
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Author: krwDate: 19:32 24-03-07
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In article <46059f7e$0$3748$ba620dc5@text.nova.planet.nl>,
burrynulnulfour@ppllaanneett.nnlll says...
> jasen wrote:
> > On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
> >> jasen wrote:
> >>> On 2007-03-16, Anthony Fremont <spam-not@nowhere.com> wrote:
> >>>> TT_Man wrote:
> >>>>>> As you said, PIC is king and it is for a reason, they
work.
> >>>>>>
> >>>>> Only if you can get to grips with the appalling op code
set..... OK
> >>>>> if you can program in C , I suppose.I can't/won't
> >>>> I only do assembler on the PIC too. What's wrong with the op-code
> >>>> set? It's RISC,
> >>> no it's not, it has too few registers to qualify.
> >> By whose definition?
> >
> > Pretty much everyones (with the exception of the PIC fans).
> >
> > google "what is risc" sometime.
> >
> >
> >
> What do you not understand about
> "Reduced Instruction Set Computer"?
The term is "Reduce Instruction Set Complexity".
> (A computer with a reduced instruction set???)
No, it's a computer with a set of less complex instructions. The set
can still be quite large and complex (e.g. PowerPC).
> A computer with about 30 instructions can be called
> a risc computer,as compared to the x86 group with about 500.
Not necessarily. If it has memory reference arithmetic instructions
(e.g. ADD R,<memory>) it is NOT a RISC processor.
> Now if you want to claim that name for something else,
> you better explain that, because I think a lot of people
> dont agree with you.
Anyone with a passing familiarity with computer architecture will.
--
Keith
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Author: LionelDate: 03:53 25-03-07
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On Sat, 24 Mar 2007 19:32:44 -0400, krw <krw@att.bizzzz> wrote:
>In article <46059f7e$0$3748$ba620dc5@text.nova.planet.nl>,
>burrynulnulfour@ppllaanneett.nnlll says...
>> jasen wrote:
>> > On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
>> >> jasen wrote:
>> >>> On 2007-03-16, Anthony Fremont <spam-not@nowhere.com> wrote:
>> >>>> TT_Man wrote:
>> >>>>>> As you said, PIC is king and it is for a reason, they
work.
>> >>>>>>
>> >>>>> Only if you can get to grips with the appalling op code
set..... OK
>> >>>>> if you can program in C , I suppose.I can't/won't
>> >>>> I only do assembler on the PIC too. What's wrong with the
op-code
>> >>>> set? It's RISC,
>> >>> no it's not, it has too few registers to qualify.
>> >> By whose definition?
>> >
>> > Pretty much everyones (with the exception of the PIC fans).
>> >
>> > google "what is risc" sometime.
>> >
>> >
>> >
>> What do you not understand about
>> "Reduced Instruction Set Computer"?
>
>The term is "Reduce Instruction Set Complexity".
No, it isn't:
<http://en.wikipedia.org/wiki/RISC>;
>> (A computer with a reduced instruction set???)
>
>No, it's a computer with a set of less complex instructions. The set
>can still be quite large and complex (e.g. PowerPC).
>
>> A computer with about 30 instructions can be called
>> a risc computer,as compared to the x86 group with about 500.
>
>Not necessarily. If it has memory reference arithmetic instructions
>(e.g. ADD R,<memory>) it is NOT a RISC processor.
>
>> Now if you want to claim that name for something else,
>> you better explain that, because I think a lot of people
>> dont agree with you.
>
>Anyone with a passing familiarity with computer architecture will.
I have more than a "passing familiarity" with computer architecture
(nearly 30 years, so far), & I don't agree with you.
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
\|/ \|/ Perna condita delenda est
---^----^---------------------------------------------------------------
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