Advice on switching microntrollers

Rich Grise, Plainclothes Hippie wrote:
> 
> Get the biggest FPGA or CPLD you can, and write the one of your
> dreams. ;-P
> 
> Personally, I rather like microprogramming, albeit I'm kind of a 
> solution in search of a problem in that respect. For example, my 
> first real computer was a "Scelbi 8-H", which had an intel 8008
> and 256 bytes of RAM. Eight toggle switches and three pushbuttons
> on the front panel, and three rows of 8 LEDs: H, L, and M. The
> buttons were, "Interrupt", "Step", and "Run". They weren't debounced,
> which was a very powerful learning experience! ;-)
> 
> I guess the point is, the 8008 "assembly language" mapped almost
> character for character onto the machine instructions, which, when
> I saw the diagram of the architecture of the 8008 <googles> Ah,
> rats. Most of the google hits are about history and crap - I was
> hoping for a diagram. But it's so freaking simple that the program
> is the equivalent of a microprogram. Like, the instructions are in
> octal, two bits of op code, and three bits each for usually the
> destination register (A,B,C,D,E,H,L,M) and three for the source
> register (see above.) "3" was the opcode for "move". And when
> you look at the architecture diagram of the 8008, you can see that
> when the instruction enters the black box, it's split up into 
> opcode, destination, and source - which go directly to the data
> selectors on the inputs or outputs, as designated! Oh, of course,
> there are other opcodes, but they had sub-codes, which still only
> needed one more level of decoding - my point being, that the 
> program for an 8008 was, essentially, a microprogram. :-)
> 
> Cheers!
> Rich

For more direct-mapped nostalgia, compare the instruction
set of Data General Nova and the Texas Instruments SN74181
ALU chip.

Another pretty easily microcoded example is the Digital
PDP-11.

-- 

Tauno Voipio
tauno voipio (at) iki fi

On 21 Oct 2005 11:55:01 -0700, larkmore@aol.com wrote:

>Ok, flamewar time I guess.
>
>I am looking to explore new microcontrollers because the ones I have
>under my belt are coming up short for what I need.  I have a lot of
>experience with the 16 series of PICs from Microchip, I have played
>with basic Stamps (I, II, SX), some experience with Motorola's HC11,
>HC12 and HC16 series.  Currently I use Atmel's AVR (Atmega128) at work.
> But in trying to branch out and find a better or at least alternate
>choice I turn to the advice of those who already have experience with
>something else.
>
>My requirements are:
>*External interrupts
>*PWM outputs (everything I've used so far has done these with hardware
>timers.  seems nice)
>*ADC inputs 8 bit resolution minimum, 10 or 12 bits nice.
>*I2C or whatever that manufacturer likes to call it.  Atmel calls it
>TWI so they don't have to pay license fees to Philips or something.
>*UART(s)
>*hardware SPI
>*JTAG nice but not required
>*CAN support would be VERY nice but not absolutely required
>*In circuit serially programmable
>*Support for a secondary external crystal (32KHz for timekeeping)
>*C friendly (and no, PICs do NOT fit this...)  As a side note, GCC
>compatible is a BIG plus.  Paying out the nose for 3rd party compilers
>is a killer.
>*SMALL!!!  I'd like to keep it smaller than an Atmega128 which is
>64TQFP at 16x16mm.

The MLF package is a LOT smaller (9 x 9 mm), and not that difficult to
work with. (Much easier than BGA).

>*Low power (sleep modes are good).  We're trying to stay below 10-20 mA
>for full speed execution and <1mA for a sleep or low power mode.
>
>My coworker would also like a cheap/free set of programming and debug
>IDEs for it.  I have experience with MPLab from Microchip and AVRStudio
>from Atmel so anything that good or better would be fine.  Just
>something graphical to step through code, set breakpoints, simulate,
>etc.
>
>So anything not made of unobtanium that you guys would recommend?

Look at the various new generation of ARM based MCUs. There are quite
a lot available from manufacturers such as Philips, Atmel, ST, Analog
Devices, TI and Freescale.

Regards
  Anton Erasmus

On Sat, 22 Oct 2005 00:08:36 +0100, Pooh Bear
<rabbitsfriendsandrelations@hotmail.com> wrote:

>
>
>larkmore@aol.com wrote:
>
>> Ok, flamewar time I guess.
>>
>> I am looking to explore new microcontrollers because the ones I have
>> under my belt are coming up short for what I need.  I have a lot of
>> experience with the 16 series of PICs from Microchip, I have played
>> with basic Stamps (I, II, SX), some experience with Motorola's HC11,
>> HC12 and HC16 series.  Currently I use Atmel's AVR (Atmega128) at work.
>>  But in trying to branch out and find a better or at least alternate
>> choice I turn to the advice of those who already have experience with
>> something else.
>>
>> My requirements are:
>> *External interrupts
>> *PWM outputs (everything I've used so far has done these with hardware
>> timers.  seems nice)
>> *ADC inputs 8 bit resolution minimum, 10 or 12 bits nice.
>> *I2C or whatever that manufacturer likes to call it.  Atmel calls it
>> TWI so they don't have to pay license fees to Philips or something.
>> *UART(s)
>> *hardware SPI
>
>You do of coursde realise that I2C and SPI just need a couple of port pins.
>
>There's nothing special about the hardware. Simply write your own device
>handler.

If one need to bit-bang these ports, then one should just note the I/O
speed of the MCU. On many of the new ARM MCUs, the possible I/O
toggling speed is a lot lower for a specific system clock speed than
for the 8-bit MCUs.

Regards
  Anton Erasmus

Rich Grise, Plainclothes Hippie wrote:

>>   I'd look at the ARM families, Philips presently have the
>> cheapest/smallest start at $1.50, and Atmel have ones with Ethernet.
>>   Pretty much everyone makes some ARMxx variant, including Freescale and
>> TI.
>> 
> 
> Or, work on new approaches to task sharing. What ever happened to
> The Connection Machine? I remember reading a thing in some mag, where
> some guy said, (I paraphrase) "Well, the only problem we have now is
> how to program the thing!" "Ah, but we have an endless supply of
> programmer flesh - undergrads!"
> 
> But nothing ever seems to have come of it.

Aahhhhhhhh!!!!, dreams of hypercubes....

There have been some interesting approaches to programming meshed and close 
coupled processor cores. Some of them have been reported in The Journal for 
Forth Applications Research. Forth was apparently the bring-up language for 
one of the MPP's.

-- 
********************************************************************
Paul E. Bennett ....................<email://peb@amleth.demon.co.uk>
Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ....EBA. http://www.electric-boat-association.org.uk/
********************************************************************

larkmore@aol.com wrote:
> Ok, flamewar time I guess.
> 
> I am looking to explore new microcontrollers because the ones I have
> under my belt are coming up short for what I need.  I have a lot of
> experience with the 16 series of PICs from Microchip, I have played
> with basic Stamps (I, II, SX), some experience with Motorola's HC11,
> HC12 and HC16 series.  Currently I use Atmel's AVR (Atmega128) at work.
>  But in trying to branch out and find a better or at least alternate
> choice I turn to the advice of those who already have experience with
> something else.
> 
> My requirements are:
> *External interrupts
> *PWM outputs (everything I've used so far has done these with hardware
> timers.  seems nice)
> *ADC inputs 8 bit resolution minimum, 10 or 12 bits nice.
> *I2C or whatever that manufacturer likes to call it.  Atmel calls it
> TWI so they don't have to pay license fees to Philips or something.
> *UART(s)
> *hardware SPI
> *JTAG nice but not required
> *CAN support would be VERY nice but not absolutely required
> *In circuit serially programmable
> *Support for a secondary external crystal (32KHz for timekeeping)
> *C friendly (and no, PICs do NOT fit this...)  As a side note, GCC
> compatible is a BIG plus.  Paying out the nose for 3rd party compilers
> is a killer.
> *SMALL!!!  I'd like to keep it smaller than an Atmega128 which is
> 64TQFP at 16x16mm.
> *Low power (sleep modes are good).  We're trying to stay below 10-20 mA
> for full speed execution and <1mA for a sleep or low power mode.
> 
> My coworker would also like a cheap/free set of programming and debug
> IDEs for it.  I have experience with MPLab from Microchip and AVRStudio
> from Atmel so anything that good or better would be fine.  Just
> something graphical to step through code, set breakpoints, simulate,
> etc.
> 
> So anything not made of unobtanium that you guys would recommend?
> Thanks!
> -Will
> 


http://www.cypress.com

Click on PSoC Mixed-Signal Controllers.

The in-circuit emulator is not free.

Cheers,
John

"Anton Erasmus" <nobody@spam.prevent.net> wrote in message

> If one need to bit-bang these ports, then one should just note the I/O
> speed of the MCU. On many of the new ARM MCUs, the possible I/O
> toggling speed is a lot lower for a specific system clock speed than
> for the 8-bit MCUs.

How is that so?  I mean, is there some kind of long propagation delay or
what?  I have played around with PICs for years, but I have been gaining
interest in the ARM micros.  This sounds like a serious issue to me.

> I am looking to explore new microcontrollers because the ones I have
> under my belt are coming up short for what I need.  I have a lot of
> experience with the 16 series of PICs from Microchip, I have played
> with basic Stamps (I, II, SX), some experience with Motorola's HC11,
> HC12 and HC16 series.  Currently I use Atmel's AVR (Atmega128) at work.
> But in trying to branch out and find a better or at least alternate
> choice I turn to the advice of those who already have experience with
> something else.
>
> My requirements are:
> *External interrupts
> *PWM outputs (everything I've used so far has done these with hardware 
> timers.  seems nice)
> *ADC inputs 8 bit resolution minimum, 10 or 12 bits nice.
> *I2C or whatever that manufacturer likes to call it.  Atmel calls it
> TWI so they don't have to pay license fees to Philips or something.
> *UART(s)
> *hardware SPI
> *JTAG nice but not required
> *CAN support would be VERY nice but not absolutely required
> *In circuit serially programmable
> *Support for a secondary external crystal (32KHz for timekeeping)
> *C friendly (and no, PICs do NOT fit this...)  As a side note, GCC
> compatible is a BIG plus.  Paying out the nose for 3rd party compilers is 
> a killer.
> *SMALL!!!  I'd like to keep it smaller than an Atmega128 which is
> 64TQFP at 16x16mm.
> *Low power (sleep modes are good).  We're trying to stay below 10-20 mA
> for full speed execution and <1mA for a sleep or low power mode.
>
> My coworker would also like a cheap/free set of programming and debug
> IDEs for it.  I have experience with MPLab from Microchip and AVRStudio
> from Atmel so anything that good or better would be fine.  Just
> something graphical to step through code, set breakpoints, simulate,
> etc.

Why not just switch to the ATmega128 in QFN package = 9 x 9 mm.
The AT90CAN128 will give you the CAN controller.
The ATmega644 will give you at least 64 kB memory in a 7 x 7 mm QFN.
The AT91SAM7 could be alternatives, but there is no 32 KHz clock.

>
> So anything not made of unobtanium that you guys would recommend?
> Thanks!
> -Will
>

-- 
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may bot be shared by my employer Atmel Nordic AB 

>> If one need to bit-bang these ports, then one should just note the I/O
>> speed of the MCU. On many of the new ARM MCUs, the possible I/O
>> toggling speed is a lot lower for a specific system clock speed than
>> for the 8-bit MCUs.
>
> How is that so?  I mean, is there some kind of long propagation delay or
> what?  I have played around with PICs for years, but I have been gaining
> interest in the ARM micros.  This sounds like a serious issue to me.
>

ARMs typically use the AMBA bus where you connect the CPU to the 32 bit 
Advanced System Bus (ASB)
and then there is a bus bridge to an Advanced Peripheral Bus (APB).
The Bus Bridge will add delays so you find bit banging will take 5-6 clocks 
at best due to delays.
The Philips LPC was so bad at this, that some new parts have the PIO on the 
ASB bus instead of on the APB bus.
The AT91SAM7 is limited by the I/O buffers but H/W can shuffle bits at 25-30 
Mbps.


-- 
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may bot be shared by my employer Atmel Nordic AB 

On Sat, 22 Oct 2005 06:42:37 +0000, Tauno Voipio wrote:

> Rich Grise, Plainclothes Hippie wrote:
>> 
>> Get the biggest FPGA or CPLD you can, and write the one of your
>> dreams. ;-P
>> 
>> Personally, I rather like microprogramming, albeit I'm kind of a 
>> solution in search of a problem in that respect. For example, my 
>> first real computer was a "Scelbi 8-H", which had an intel 8008
>> and 256 bytes of RAM. Eight toggle switches and three pushbuttons
>> on the front panel, and three rows of 8 LEDs: H, L, and M. The
>> buttons were, "Interrupt", "Step", and "Run". They weren't debounced,
>> which was a very powerful learning experience! ;-)
>> 
>> I guess the point is, the 8008 "assembly language" mapped almost
>> character for character onto the machine instructions, which, when
>> I saw the diagram of the architecture of the 8008 <googles> Ah,
>> rats. Most of the google hits are about history and crap - I was
>> hoping for a diagram. But it's so freaking simple that the program
>> is the equivalent of a microprogram. Like, the instructions are in
>> octal, two bits of op code, and three bits each for usually the
>> destination register (A,B,C,D,E,H,L,M) and three for the source
>> register (see above.) "3" was the opcode for "move". And when
>> you look at the architecture diagram of the 8008, you can see that
>> when the instruction enters the black box, it's split up into 
>> opcode, destination, and source - which go directly to the data
>> selectors on the inputs or outputs, as designated! Oh, of course,
>> there are other opcodes, but they had sub-codes, which still only
>> needed one more level of decoding - my point being, that the 
>> program for an 8008 was, essentially, a microprogram. :-)
>> 
>> Cheers!
>> Rich
> 
> For more direct-mapped nostalgia, compare the instruction
> set of Data General Nova and the Texas Instruments SN74181
> ALU chip.
> 
> Another pretty easily microcoded example is the Digital
> PDP-11.

I had an opportunity to use an editor on a PDP-11 and cross-assembler
to write some test stuff for an IMP-16:
http://www.bitsavers.org/pdf/national/imp16/4200036A_IMP16P_Descr_1974.pdf
The company had the naked boards in stock, to use in another thing; they
didn't have that box.
There's more stuff:
http://www.bitsavers.org/pdf/national/imp16/
And, I believe I've seen the 74181s, or maybe AM2903s, on a PDP-11's CPU
board. I also once worked on an all-TTL "microprogrammable processor",
but it was 32 bits, and was used to test disk drives. That one had even
TTL RAM. The instruction cycle was 168 ns, which was unheard of at the
time. And, the thing that really makes the microprogram stand out as a
microprogram is the "next instruction" field in the instruction. The
G-15's machine language was like that too, but that was for timing,
since all of the memory was circulating on a magnetic drum.

Ah, I nostalge. <sigh> Sorry.

Cheers!
Rich

On Fri, 21 Oct 2005 11:55:01 -0700, larkmore wrote:

> Ok, flamewar time I guess.
> 
> I am looking to explore new microcontrollers because the ones I have
> under my belt are coming up short for what I need.  I have a lot of
> experience with the 16 series of PICs from Microchip, I have played
> with basic Stamps (I, II, SX), some experience with Motorola's HC11,
> HC12 and HC16 series.  Currently I use Atmel's AVR (Atmega128) at work.
>  But in trying to branch out and find a better or at least alternate
> choice I turn to the advice of those who already have experience with
> something else.
> 
> My requirements are:
<yadda yadda>

sounds like a job for a dspic to me. Maybe a dsPIC30F2010. They are pretty
nice, particularly if you have pic16 experience.

---
Regards,
  Bob Monsen

Beyond the natural numbers, addition, multiplication, and mathematical 
induction are intuitively clear.
- Luitzen Brouwer (1881-1966) (intuitionist)