81–90 of 98 posts
>Due to lack of programming tools and evaluation boards I was only able to review most devices by datasheet hmm. Well I don't blame the author but that kinda killed my interest
>Due to lack of programming tools and evaluation boards I was only able to review most devices by datasheet hmm. Well I don't blame the author but that kinda killed my interest
I wonder what the lowest-priced chip you can pick up with a reasonable toolchain that is accessible to hobbyists?
You would be surprised by the places sub-$1 mcus appear, even down to a dime. Car manufactures use them all over the place, even ECUs(at least until recently; I'm no longer "in the biz"). Yes, shaving a few pennies from the BOM of a $30K device is still worth doing when you produce them in huge volume.
>Due to lack of programming tools and evaluation boards I was only able to review most devices by datasheet hmm. Well I don't blame the author but that kinda killed my interest
I wonder what the lowest-priced chip you can pick up with a reasonable toolchain that is accessible to hobbyists?
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The yuan-usd exchange rate has floated around 6:1 until recently, with yuan denominated down to 0.01. So possibly that.
Nailed it. https://en.wikipedia.org/wiki/Jiao_(currency)
1/6 of a penny is 0.0016 USD, or 0.01 CNY: https://www.google.com/search?q=0.0016+usd+to+cny
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I would think a lot of manufacturers are looking to RISC-V for that kind of eventuality. But in the meantime, and looking at that chart, it seems a lot more convenient to just rip off the PIC.
I don't think a RISC-V would fit in this gate count niche. Just the register file for an RV32-C core is half these chips' RAM.
The ALU can be a reasonable chunk of the processor size, and an 8-bit ALU is going to be much smaller than a RISCV ALU. Although I read somewhere that some of the Z80s, although an 8-bit processor, had a 4-bit ALU, and also I read somewhere that the 32-bit NIOS processor has a 16-bit ALU. But whether that's true or not ...
I designed a size optimised 16-bit MSP430 clone for small size low cost machxo3 FPGAs that used an 8-bit ALU. It a good way of keeping the number of LUTs down when optimising for size over speed.
For something like the low cost ice40 FPGAs, a PIC would probably be a very good match for those too compared to RISCV, because ice40 doesn't have distributed memory, which is what you'd like for register files (otherwise I expect one of the block RAMs would be used for the register file, and ideally you wouldn't want that to happen).
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"metric butt-load of mask-programmable ROM" What would that be in this context? I'm guessing we're talking KB rather than TB?
I'd guess about 1 MB order of magnitude. That would be a butt-load even for samples. 1 MB would be enough for 45 seconds audio at 8 bit PCM @22 kHz. If they're half competent, they could use ADPCM or much better (and cheaper to decode too!) vector quantization. With VQ, you could go even down to ~1 bits (~6 minutes of audio per megabyte) per sample while maintaining good audio quality. Decoding is very simple, so 650…
Makes sense.
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I don’t know how, or why, but I’ve bought the same Phillips toothbrush for $20 from AliExpress when my original broke. And I buy the heads from Asia too for a fraction of the store price.
The heads aren’t Phillips, just clones right? I would expect the brush you are buying to be a clone also, or at best a good knock off. Phillips is pretty disciplined about their pricing internationally. I buy cloned heads (but not the main brushes) and find them completely adequate.
Agreed, they work fine.
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Could mcu's made using modern processes be as cheap ?
The other issue is that the older nodes are more reliable. They're already matured where they understand how to make everything work right. On top of that, each process shrink introduces new challenges that can cause components to fail. The most modern nodes seem like they make everything somewhat broken coming out the door with designers building in mitigations for that. They don't last as long. The older nodes don'…
Do you have funding to do a MOSIS run or two? I wonder if we could find some.
These have their uses. A friend who frequently does contract development in the toy space has (or at least used to have) a favorite go-to MCU that costs under $0.06 in bare die. It is essentially a 6502 with 100 bytes of RAM and a metric butt-load of mask-programmable ROM. It was originally designed for greeting cards. He has designed it into toys. It is hard to use, you need a dev kit and a good relationship with th…
>6502 Without question, one of the nicest platforms to have in multitudes of thousands, at low energy and cost ..