4 ms·

I just finished an undergraduate class on microcontroller applications that used a MC68HC12 dev board. We coded in Assembly and then later in C. I'm curious,

I just finished an undergraduate class on microcontroller applications that used a MC68HC12 dev board. We coded in Assembly and then later in C. I'm curious, is this a typical platform in other computer engineering programs in the US?

shimonabi 4y ago
At our company we still use a MC68HC11 for an industrial device.
- exmadscientist 4y ago
  Be careful -- they're rapidly going obsolete. No one wants to fab old EPROM processes, and no one wants to package PLCCs anymore. If it's neither of those, I think you've got a bit more time. There are "compatibles" out there, and some of them are very good indeed, but they're not without their hassles.
  - mark-r 4y ago
    I think I have a 68HC11 sitting around that I picked up for a project and never used. I wonder if it's worth anything?
    - exmadscientist 4y ago
      One-off hobbiest/repairman/desperation quantities will be available for years. It's industrial, new-build quantities that are going to be problems. And, yes, the 68HC11 was on December's EOL list, so I hope anyone who was using it in products has a plan! (Or hire my company, we fix things like that... not that it's the most fun work in the world, we have other things we'd rather be doing....)
      - jacquesm 4y ago
        Can't you just use one of these? https://www.microsemi.com/existing-parts/parts/151966 https://www.microsemi.com/existing-parts/parts/151966
deleted 4y ago
[deleted]
PAPPPmAc 4y ago
The university I'm attached to used 68HC11-family dev boards for their intro embedded course until the early/mid 2010s, with a smattering of other platforms like 8051 derivatives in advanced classes, and have switched to ARM (Small Cortex M ARMs, typically TI TM4C123 TivaC boards) for almost all our embedded content since. Plus a few little Arduino based activities with the freshmen, though the form of that has changed over the years. The intro to embedded systems course used to be only taken by Computer Engineers around their Junior year, since ~2017 we do it a semester or so earlier and make the EEs take it too as part of a streamline; EEs no longer take the computer architecture course, and the new embedded course covers some basic architecture concepts. We still do the beginning of the semester in Assembly (we really only show them ARM Thumb) and the later part in C. Possibly the most revelatory thing about that course is that the low-level view means we find out and try to correct that most of our students (as second semester sophomores who have in theory passed at least two programming courses and a digital logic course) haven't the slightest idea what code actually means/does. Example: Every semester I've been involved, when we transition from assembly to C, we give a simple assignment to sort some arrays of (well documented) structs by a specified field and order, given the address where first element starts and length in elements, in both C and assembly. They are handed a starter project with a lightly-obfuscated object file that sets up the arrays, calls two provided function headers for them to fill in, then tests if the sorts succeeded. Details get changed every semester because students cheat compulsively on programming assignments, but it's always set up to be easy, the structs they handle in ASM are always 16 or 32b in length, stored aligned, etc. Many of them... struggle mightily for two weeks because they haven't actually retained anything about number representation, memory (size, layout, byte addressing), arguments, the difference between a value and a pointer, and so on. The course staff spend weeks doing patient remediation around that point in the semester. At least we get a chance to make another pass over that material and more of them get it after.
mtnygard 4y ago
I had a similar course using the 68HC11... but that was in 1991 or '92. I am (pleasantly) surprised to hear that this kind of class is still running. Haven't done embedded for a long time, so I don't know if the 68HC12 is current or not. Wouldn't worry thouhg. Even if that chip is not in wide use now, the skills you learned are transferrable to any other.
hakfoo 4y ago
My CS programme (class of 2003) had one semester of assembly programming, either 68HC11 or 8086. I took the 8086 flavour and it was definitely designed around dev-board style development rather than expecting a rich BIOS/OS support environment. There was a more embedded-focus "Computer Systems Engineering" degree option which involved a lot more assembly..

shimonabi 4y ago

At our company we still use a MC68HC11 for an industrial device.

exmadscientist 4y ago
Be careful -- they're rapidly going obsolete. No one wants to fab old EPROM processes, and no one wants to package PLCCs anymore. If it's neither of those, I think you've got a bit more time. There are "compatibles" out there, and some of them are very good indeed, but they're not without their hassles.
- mark-r 4y ago
  I think I have a 68HC11 sitting around that I picked up for a project and never used. I wonder if it's worth anything?
  - exmadscientist 4y ago
    One-off hobbiest/repairman/desperation quantities will be available for years. It's industrial, new-build quantities that are going to be problems. And, yes, the 68HC11 was on December's EOL list, so I hope anyone who was using it in products has a plan! (Or hire my company, we fix things like that... not that it's the most fun work in the world, we have other things we'd rather be doing....)
    - jacquesm 4y ago
      Can't you just use one of these? https://www.microsemi.com/existing-parts/parts/151966 https://www.microsemi.com/existing-parts/parts/151966

deleted 4y ago

[deleted]

PAPPPmAc 4y ago

The university I'm attached to used 68HC11-family dev boards for their intro embedded course until the early/mid 2010s, with a smattering of other platforms like 8051 derivatives in advanced classes, and have switched to ARM (Small Cortex M ARMs, typically TI TM4C123 TivaC boards) for almost all our embedded content since. Plus a few little Arduino based activities with the freshmen, though the form of that has changed over the years. The intro to embedded systems course used to be only taken by Computer Engineers around their Junior year, since ~2017 we do it a semester or so earlier and make the EEs take it too as part of a streamline; EEs no longer take the computer architecture course, and the new embedded course covers some basic architecture concepts. We still do the beginning of the semester in Assembly (we really only show them ARM Thumb) and the later part in C. Possibly the most revelatory thing about that course is that the low-level view means we find out and try to correct that most of our students (as second semester sophomores who have in theory passed at least two programming courses and a digital logic course) haven't the slightest idea what code actually means/does. Example: Every semester I've been involved, when we transition from assembly to C, we give a simple assignment to sort some arrays of (well documented) structs by a specified field and order, given the address where first element starts and length in elements, in both C and assembly. They are handed a starter project with a lightly-obfuscated object file that sets up the arrays, calls two provided function headers for them to fill in, then tests if the sorts succeeded. Details get changed every semester because students cheat compulsively on programming assignments, but it's always set up to be easy, the structs they handle in ASM are always 16 or 32b in length, stored aligned, etc. Many of them... struggle mightily for two weeks because they haven't actually retained anything about number representation, memory (size, layout, byte addressing), arguments, the difference between a value and a pointer, and so on. The course staff spend weeks doing patient remediation around that point in the semester. At least we get a chance to make another pass over that material and more of them get it after.

mtnygard 4y ago

I had a similar course using the 68HC11... but that was in 1991 or '92. I am (pleasantly) surprised to hear that this kind of class is still running. Haven't done embedded for a long time, so I don't know if the 68HC12 is current or not. Wouldn't worry thouhg. Even if that chip is not in wide use now, the skills you learned are transferrable to any other.

hakfoo 4y ago

My CS programme (class of 2003) had one semester of assembly programming, either 68HC11 or 8086. I took the 8086 flavour and it was definitely designed around dev-board style development rather than expecting a rich BIOS/OS support environment. There was a more embedded-focus "Computer Systems Engineering" degree option which involved a lot more assembly..