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Rust is by definition for new projects, so there are simply no more 8-bit microcontrollers around. Those things are moving into museums. And good riddance, M0s
by revelation 9y ago
Rust is by definition for new projects, so there are simply no more 8-bit microcontrollers around. Those things are moving into museums. And good riddance, M0s are soo much better.
- shakna 9y ago> so there are simply no more 8-bit microcontrollers around Atmel still produce a significant number of 8bit AVRs.
- fit2rule 9y agoYeah .. http://www.mouser.at/Semiconductors/Integrated-Circuits-ICs/Embedded-Processors-Controllers/Microcontrollers-MCU/8-bit-Microcontrollers-MCU/_/N-a86lo http://www.mouser.at/Semiconductors/Integrated-Circuits-ICs/... Apropros "M0's being so much better", this is not really an attitude that produces effective results in "the embedded" world. True fact: in embedded, many times you want the least powerful solution. 8-bit MCU's are freakin' everywhere, and they are not going anywhere.
- foldr 9y agoModern ARM Cortex M0 MCUs are cheaper than AVRs, use less power, and have much better peripherals. The only reason to use an AVR MCU these days is if you (i) need to run it off a 5V rail or (ii) you prototyped your product with an Arduino.
- kevin_thibedeau 9y agoCortex M has higher I/O latency.
- foldr 9y agoAre you referring to the fact that you can switch a GPIO port with a single instruction on an 8-bit micro? That's true, but you can usually run the ARMs at higher clock speeds.
- SAI_Peregrinus 9y agoCheapest M0 on Digikey: https://www.digikey.com/product-detail/en/cypress-semiconductor-corp/CY8C4013SXI-400T/CY8C4013SXI-400T-ND/5113942 https://www.digikey.com/product-detail/en/cypress-semiconduc... Cheapest 8-bit AVR on Digikey: https://www.digikey.com/product-detail/en/microchip-technology/ATTINY5-MAHR/1611-ATTINY5-MAHRCT-ND/6833241 https://www.digikey.com/product-detail/en/microchip-technolo... 2.5x the price is not cheaper.
- foldr 9y agoOk, yes, at the very very low end (that thing has 6 pins!) you might get an AVR for slightly cheaper. My point was that you typically get better price, power usage and performance from a Cortex M0. If you have $1 to spend, for example, there is rarely any advantage to going with AVR.
- losvedir 9y ago2.5x doesn't seem like a useful way of looking at it. It's $0.24 vs $0.49. What kind of devices are these things going in? It matters if the rest of the components are $1, not so much of they're $10.
- SAI_Peregrinus 9y agoA lot of the devices they're going in are at or below the $5 retail price. So the COGS has to be under $2 to make a reasonable profit. That doesn't leave much room to waste money on your BOM.
- coupdejarnac 9y agoFor very low quantities, the price difference won't matter much.. If you're selling hundreds of thousands or millions of something, suddenly that is real money that justifies the incremental increase of engineering effort to use a cheaper part.
- jimmyswimmy 9y agoI used to sell parts to Compaq when they made their own server boards. Design manager was trying to iron millibucks out of the BOM cost. That's tenths of pennies. It matters even if you're charging $100. Those pennies add up when you're selling 10-100ku per month on multiple product lines.
- revelation 9y agoAtmel have just been bought by Microchip in an industry-wide reorganization that is sure to swallow the 8 bit micros. And of course they still make tons of them, it's embedded, you need to supply these chips for another 10 years for old designs. But you shouldn't use an 8-bit uC in a new design.
- shakna 9y ago> that is sure to swallow the 8 bit micros. What makes you say that? MicroChip released new xMega's in May. [0] [0] http://www.microchip.com/wwwproducts/en/ATXMEGA64A1U http://www.microchip.com/wwwproducts/en/ATXMEGA64A1U
- Kelbit 9y agoMicrochip's bread and butter is still cheap 8-bit controllers like the PIC10/12/14/16/18 families. Many devices don't need a 32-bit core, so wasting a few cents on each unit by specifying one drives up cost at high volume. While the core of a 32-bit controller doesn't take up much die area at smaller process nodes, core size has never really been the limiting factor with MCUs. Look at any MCU die - the flash and RAM both dominate in size over the logic. Going to a 32 bit controller generally means that your instructions are going to be wider, so your program space is going to take up more flash. You will also tend to use more RAM unless you are judicious about word size, and a context switch on an RTOS will cost more memory since the context contains much wider registers. Another pain point with the 32-bit MCUs is that ARM currently dominates the market, and their licensing fees add a few cents to the cost of each part - which can be a killer at volume. There have been attempts to break ARM's monopoly (most notably Microchip's MIPS-based PIC32 series) but it seems like ARM will continue to dominate this space in the years to come. As a final note, SiLabs recently introduced an ultra-low power microcontroller line based on the venerable 8-bit 8051 core, so clearly they think that 8-bit MCUs have a role to play in the years to come.
- alacombe 9y agoIntel 8051 are widely deployed in IoT devices.
- SAI_Peregrinus 9y agoThere are plenty. They're ridiculously cheap, so they get used everywhere. Checking DigiKey for the cheapest 8 bit and 32 bit micros: Atmel's ATTiny5-MAHR is $0.196 each at qty 100 (no further price breaks listed, full reel of 3000 is non-stock/call for price). The Cypress CY8C4013SXI-400T is $0.49 each at qty 2500 (full reel). 2.5x the price is a big difference, and matters a lot when you're producing thousands or millions of something. Tons of power supplies use an 8-bit (or even 4-bit) microcontroller instead of or in addition to a dedicated switchmode controller ASIC. They're also ridiculously common as LED dimmer controllers, keypad controllers for microwave ovens, etc. 8-bit micros aren't going anywhere any time soon. Price matters too much.
- DamonHD 9y agoNo: pick the right tool for the job. Wasting money in the MCU is probably wasted 5x to 10x over in the price of the product embedding the MCU. And if that's a consumer product, good luck with the competition.
- d21d3q 9y agoHaving more power full mcu (and with more ram) can reduce time to market. You can use some rtos, heavy libraries, oversized buffers etc.