8-bit uC - is there even a point?

[wraper]

They made an ARM1. That is licence free. To make a commercial product they have licence free options. like the RISC/V. People usually can't escape all royalties, because they will have to used some silicon IP, like a flash block. Since these people are not using any silicon technology, they will be creating 100% of their process related IP.

It is cortex M0, not ARM1. In video was even said that it will become commercially viable when they will make a single chip few mm in size. Which means it's not commercially viable currently. And who would make a real product based on ARM1 to begin with?
EDIT: And anyway, it's not something you would use in a low and likely medium quantity product. It's a niche thing, flexible electronics. You won't solder this thing on the PCB.

[technix]

They made an ARM1. That is licence free. To make a commercial product they have licence free options. like the RISC/V. People usually can't escape all royalties, because they will have to used some silicon IP, like a flash block. Since these people are not using any silicon technology, they will be creating 100% of their process related IP.

It is cortex M0, not ARM1. In video was even said that it will become commercially viable when they will make a single chip few mm in size. Which means it's not commercially viable currently. And who would make a real product based on ARM1 to begin with?
EDIT: And anyway, it's not something you would use in a low and likely medium quantity product. It's a niche thing, flexible electronics. You won't solder this thing on the PCB.

If it were ARM1 or ARM2 it could have been 1 cent: those cores have long past their patent expiry dates, and if you recreate the cores using a free implementation (e.g. the open source Amber core, which implements ARM2) there is nothing you need to pay other than fab. If you can squeeze the economy of scale up you get that price point.

Although if ou use RV32IMC it would have the same benefit.

[wraper]

If it were ARM1 or ARM2 it could have been 1 cent: those cores have long past their patent expiry dates, and if you recreate the cores using a free implementation (e.g. the open source Amber core, which implements ARM2) there is nothing you need to pay other than fab. If you can squeeze the economy of scale up you get that price point.

And no one would buy them because they would suck, therefore not possible to make such amounts to achieve low cost.

[brucehoult]

If it were ARM1 or ARM2 it could have been 1 cent: those cores have long past their patent expiry dates, and if you recreate the cores using a free implementation (e.g. the open source Amber core, which implements ARM2) there is nothing you need to pay other than fab. If you can squeeze the economy of scale up you get that price point.

ARM7TDMI was 1994. That should be out of protection now.

Although if ou use RV32IMC it would have the same benefit.

Just RV32IM for ARM2 equivalence. C gets you to competitive with Thumb2 on code size, and better and much cleaner than the mix of ARM32 and Thumb1 you need on ARM7TDMI.

Cortex M0(+) is of course almost exactly Thumb1 without any ARM mode and just a couple of extra instructions to handle system tasks.

I expect ARM2 code is a bit more compact than RV32IM -- they do get some benefit from predication, the free shifter on the 2nd argument, all those addressing modes, and LDM/STM. But RISC-V gets a decent size and speed benefit from the single-instruction "compare two registers and branch" instruction. And ARM needs to spill variables to RAM a lot more (and only passes 4 arguments in registers). I don't know if anyone has made a close comparison as ARM32 is basically obsolete and Thumb2 is what everyone uses. On RISC-V if you have more than maybe 1 KB of program code then it's a net benefit to implement the 16 bit instructions, so basically everyone does RV32IMC if not RV32IMAC (the Atomic instructions are trivial to implement if you only have one processor)

[technix]

If it were ARM1 or ARM2 it could have been 1 cent: those cores have long past their patent expiry dates, and if you recreate the cores using a free implementation (e.g. the open source Amber core, which implements ARM2) there is nothing you need to pay other than fab. If you can squeeze the economy of scale up you get that price point.

ARM7TDMI was 1994. That should be out of protection now.

Then why is LPC2103 and AT91SAM7S128 still that damn expensive?

Speaking of, since Cortex-A72 can still run ARM7TDMI code almost as-is, how much of ARM7TDMI isn’t covered in newer patents?

[GeorgeOfTheJungle]

And no one would buy them because they would suck [...]

But never as much as that chinese 3 cents µC 

[brucehoult]

ARM7TDMI was 1994. That should be out of protection now.

Then why is LPC2103 and AT91SAM7S128 still that damn expensive?

Interesting. $8 - $10.

Is there any good reason to use one of those rather than a Cortex M, other than "we already have a product and don't want to redesign it"?

[GeorgeOfTheJungle]

I don't think I've ever seen as much loathing of a computer design as you get when you push a paged solution, or as much relief as you get when you tell people you're going to stretch the address registers to solve their memory constraints.

Yes, exactly, the Apple IIe's AUX mem was perhaps the best example of how not to do it. Even worse, you can never be completely sure what state it's in after a reset!

[mikeselectricstuff]

ARM7TDMI was 1994. That should be out of protection now.

Then why is LPC2103 and AT91SAM7S128 still that damn expensive?

Interesting. $8 - $10.

Is there any good reason to use one of those rather than a Cortex M, other than "we already have a product and don't want to redesign it"?

Exactly this. Also lower volumes.
Would you rather a part you use in production went obsolete an unobtainable  overnight, or just increased in price ?

[nctnico]

If it were ARM1 or ARM2 it could have been 1 cent: those cores have long past their patent expiry dates, and if you recreate the cores using a free implementation (e.g. the open source Amber core, which implements ARM2) there is nothing you need to pay other than fab. If you can squeeze the economy of scale up you get that price point.

ARM7TDMI was 1994. That should be out of protection now.

Then why is LPC2103 and AT91SAM7S128 still that damn expensive?

Probably because these are old MCUs and are now being milked to support legacy designs. They used to be a whole lot cheaper a decade ago.

[coppice]

If it were ARM1 or ARM2 it could have been 1 cent: those cores have long past their patent expiry dates, and if you recreate the cores using a free implementation (e.g. the open source Amber core, which implements ARM2) there is nothing you need to pay other than fab. If you can squeeze the economy of scale up you get that price point.

ARM7TDMI was 1994. That should be out of protection now.

Then why is LPC2103 and AT91SAM7S128 still that damn expensive?

Probably because these are old MCUs and are now being milked to support legacy designs. They used to be a whole lot cheaper a decade ago.

They are probably cheap now, if you are a serious user still running a production line.

[brucehoult]

If it were ARM1 or ARM2 it could have been 1 cent: those cores have long past their patent expiry dates, and if you recreate the cores using a free implementation (e.g. the open source Amber core, which implements ARM2) there is nothing you need to pay other than fab. If you can squeeze the economy of scale up you get that price point.

ARM7TDMI was 1994. That should be out of protection now.

Then why is LPC2103 and AT91SAM7S128 still that damn expensive?

Probably because these are old MCUs and are now being milked to support legacy designs. They used to be a whole lot cheaper a decade ago.

They are probably cheap now, if you are a serious user still running a production line.

Serious users running production lines who only need ARM7TDMI performance (or even M3/M4) should probably be thinking about making their own SoC with as much as possible of the other chips they're using now integrated onto it.

I think you can now get a mask set for 180nm for $30k or so and even less for 350nm and then go into making a wafer worth of your custom SoC whenever you need for ... I'm not sure ... maybe $1 each.