what's wrong with a pic ?

Or look at the Freescale 56F8xxx hybrid dsps. For small code sizes, the compiler tools are free (with different prices as the code size limit increases).

Not that the PIC is bad, but if you're a Linux user, you'll like being able to program an AVR using gcc on your Linux desktop.

Maybe I could, if all I expected from the PCM was an occasional squirt and a bang. However, just as I would expect the new crank to do everything the original crank did, so I would expect the new "from scratch" PCM to behave. You have no idea what functionality is incorporated into a PCM in just the software, much less the hardware, to be able to make your statement. My name isn't Donald Trump.

An "appalled physicist" showed his ignorance on this same topic almost exactly ten years ago in this very ng. Try Google Groups with msg ID

snipped-for-privacy@kok-ts0-16.holli.com

for an attempt to enlighten him.

~Dave~

Actually, getting the object code would involve a trip or two to the junkyard to get a readable flash. Of course, your FPGA will need an exact equivalent to the Motorola TPU since part of the code on the flash is microcode for the TPU. And that's what does spark and fuel.

~Dave~

... snip ...

For most of todays automobile uses, that would probably be a healthy advance. If you stand around waiting for the bus somewhere, amuse yourself by counting the passengers per passing car. I doubt the average will exceed 1.5, and will probably be closer to 1.1.

--
"If you want to post a followup via groups.google.com, don't use
 the broken "Reply" link at the bottom of the article.  Click on 
 "show options" at the top of the article, then click on the 
 "Reply" at the bottom of the article headers." - Keith Thompson
More details at: 
Also see

You could also use a new Freescale device with a TPU, such as the MPC5xx or MCF523x devices (not quite object code compatible, however). And it's unlikely that the 68332 will be unavailable in the near future - Motorola have been trying to persuade customers for years to move to the MPC5xx devices, but the 68332 is as popular as ever. Even if they stop making it, Atmel second-sources a radiation hard 68332, although I suspect they charge slightly more than Freescale.

I would buy one in the blink of an eye if it was manufactured again at a reasonable price.

(Why? Trying to bring this thread back to something related to embedded systems: "There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies and the other is to make it so complicated that there are no obvious deficiencies. C. Hoare)

Failing that, I'll have to wait until the Smart "fortwo" (

) is introduced in the USA.

Though I dislike the PIC, you can also program it on a linux box.

Ian

You are right - poor old memory - ISTR having to set the call address into a register then designating that register as the PC in order to do a call.

Ian

A very wide range. My first volume design was the Dragon 32 home computer in

1981 (used a 6809, still one of the best ever 8 bit microprocessors IMHO). Other products include a toy typewriter based on an 8051 variant, a mains comms. system based on the 6802, a range of electronic label makers based on various Hitachi and Fujitsu microcontrollers, a franking machine which had, IIRC an H8, a Samsung 4 bitter and a specialised encyption micro, not to mention a couple of CO monitors, the first based on a Z8 and the second using a PIC.

For each of these applications the first part of the development was concerned with defining the features, functions and performance of the product and finding the best pieces of hardware to do the job. None of these applications is trivial, even the CO monitor. There were sveral contenders for this project but the PIC one on price. These units are made in many hundreds of thousands a year.

Ian

Please name the devices you are talking about.

Ian

You've hit the nail on the head! In most US cities you may have to stand around quite a while waiting for that bus. Here in our city of 50,000 in Western Oregon, you may wait either 1/2 hour or 1 hour--and are unlikely to find a covered shelter. (It's rained about 1.5 inches in the last 3 days).

It's an unfortunate fact that many of the smaller communities and the jobs in and around them have grown in such a way as to make efficient public transportation very difficult. Cheap gas and private autos have made it possible for small and large businesses to find locations outside the major cities where property costs are lower and the 'quality of life' for employees is better. I would guess that the average commute for the

3000 HP employees at the plant 100 yards south of my home is about 7 miles, and only about 1/3 of them could get there using public transportation. If those 1000 people could find a way to take the bus to work, it would probably double the morning bus ridership for the whole city and would require massive rerouting or more buses.

Mark Borgerson

Could you buy a reasonably priced processor or FPGA with the speed and capacity to emulate a 68332 ten years ago?

The thread you cited was interesting, but seemed more about OO programming than engine control hardware.

As for OO programming, I don't soon expect to see a car that requires periodic internet connection to be able to load the latest version of the Microsoft .NET run-time package! ;-)

Mark Borgerson

There is at least one Linux hosted PIC compiler also. Of course the code size is 50% larger than an AVR and 100% larger than a '430.

--
Grant Edwards                   grante             Yow!  This is a NO-FRILLS
                                  at               flight -- hold th' CANADIAN
                               visi.com            BACON!!

But we're not talking off-the-shelf '332s here. These are special ones which don't even show up in Freescale's catalog.

~Dave~

Yes--the 68332 variants we used. Motorola was very accommodating. It had something to do with the fact that the volume for our PCM was two+ million, and ours wasn't the only PCM. But there are a whole bunch of ICs surrounding the micro. Except for the flash, they are all special purpose. It's amazing that the PCM is expected to continue running when the starter is engaged and battery voltage takes a dive.

The thread was about OO, but that specific branch dealt with engine controller SW--size and functionality. A PCM is not just a carburetor with a micro plugged into it.

Quick question to be answered without thinking: What does pressing the gas pedal do?

The correct answer is not "increases gas flow to the engine." That is a secondary effect. It's all about airflow, in carburetted engines and PCM controlled engines.

requires

Well, there were discussions about the cars connecting to the internet to get software updates. 8-) And some do connect to OnStar to send the owner email about maintenance/diagnostics.

~Dave~

I guess that depends on a number of factors:

1. is the engine diesel or gasoline? (I'll assume gasoline for now).

1. On a carbureted engine---which I learned about as part of Agricultural Practices 101 at UC Davis in 1967--- A. pressing the gas pedal activates the throttle pump to put a squirt of gas into the air stream (After the throttle plate IIRC). B. Opens the throttle plate to admit more air flow---which causes more fuel flow through the carburetor jets. C. Reduces manifold vacuum pressure--at least temporarily. This changes the spark timing through a vaccum connection to the distributor. D. Helps the engine generate more power, I hope.

ON a fuel-injected, MPU-controlled engine, I think it might have these effects:

1. Opens the throttle plate to increase air flow
2. The engine sensors note the change in manifold vaccuum and adjust the fuel injector timing to provide more gas.
3. Adjusts spark timing to match new requiements

I don't even know if the engine controller even senses the throttle position directly, or indirectly through such sensors as the manifold vacuum sensor.

I think it's been that way since the first effective carburetors.

Our Prius did have to go into the shop for an engine controller firmware upgrade. I don't recall the problems that necessitate the upgrade.

Mark Borgerson

I would guess that the differences are in the TPU microcode, rather than the core 68K instructions or other peripherals.

Mark Borgerson

Every car I've ever owned - with the sole exception of my '65 Scout ;)

- has had a firmware upgrade during its life. 86 Galant, 2002 Focus,

1994 Taurus, 1998 Escort.