3 ms·
An ATtiny really isn't good value for money, except when looking for something simple to use. The CH32V003 is $.10-$.20, quite usable in my experience and feat
by danhor 2y ago
An ATtiny really isn't good value for money, except when looking for something simple to use.
The CH32V003 is $.10-$.20, quite usable in my experience and features a 16 kB ROM, 2 kB RAM and a 32-bit 48 MHz RISC-V.
The PMS150 is available for <$.05 with ~1.5 kB ROM, 60 B RAM and an 8-bit 8 MHz CPU.
If you're excluding chinese manufacturers, the STM32G030 is sub-$.80 in quantity for 32 kBs of ROM, 8 kBs of RAM and a 32-bit 64 MHz ARM CPU.
- fragmede 2y agowhich is to say, an MMU to run a full blown operating system, and not a small C program with some interrupt handlers.
- kragen 2y agonone of these have mmus, even the stm32g030 is a cortex-m0+
- fragmede 2y agodang. thanks for the correction. Looks like the cheapest chip with an MMU is the Allwinner F1C100S which is $2.20 in quantity.
- kragen 2y agohappy to explore with you! mmus are a performance hack; they make your memory-protected code run faster than if you use a jit compiler that inserts memory bounds checks. but suppose running code that way costs you a factor of 10× in performance. so maybe your 30-dhrystone-mips processor (https://www.lcsc.com/product-detail/Microcontrollers-MCU-MPU-SOC_PUYA-PY32F002AL15S6TU_C5292060.html https://www.lcsc.com/product-detail/Microcontrollers-MCU-MPU..., say, or https://www.lcsc.com/product-detail/Microcontrollers-MCU-MPU-SOC_Infineon-Cypress-Semicon-CY8C4045FNI-DS400T_C2952624.html https://www.lcsc.com/product-detail/Microcontrollers-MCU-MPU... for 2×) performs roughly like a 3 dhrystone mips processor. if we believe https://netlib.org/performance/html/dhrystone.data.col0.html https://netlib.org/performance/html/dhrystone.data.col0.html that's roughly the performance of a sun 3/160, an amiga 2000, or a 40 megahertz amd clone 80386 pc (though much slower than an intel 386) that's much faster than many multiuser machines i've used the promise of java (and oberon) was that such large runtime overhead would be unnecessary with better static checking, and j2me and oberon seem to have largely borne that out the bigger issue is i think that cheap microcontrollers don't have much ram or off-chip bandwidth. if you want a megabyte on-chip, you end up with things like https://www.digikey.com/en/products/detail/stmicroelectronics/STM32H750VBT6/9453371 https://www.digikey.com/en/products/detail/stmicroelectronic... (a 480-megahertz cortex-m7 with 128 kibibytes of flash and a mebibyte of ram for usd11.27), https://www.digikey.com/en/products/detail/infineon-technologies/CY8C624AFNI-S2D43T/16516853 https://www.digikey.com/en/products/detail/infineon-technolo... (a dual-core 150-megahertz cortex-m0+ with 2 mebibytes of flash and a mebibyte of ram for usd12.92), https://www.digikey.com/en/products/detail/nxp-usa-inc/MIMXRT1062DVL6B/13635843 https://www.digikey.com/en/products/detail/nxp-usa-inc/MIMXR... (a 600-megahertz cortex-m7 using external program memory and a mebibyte of ram for usd14.48), or https://www.digikey.com/en/products/detail/renesas-electronics-corporation/R5F572NNHDFP-30/12750997 https://www.digikey.com/en/products/detail/renesas-electroni... (a 240-megahertz renesas rx72n with 4 mebibytes of flash and a mebibyte of ram for usd20.85) i'm pretty sure none of these have mmus either but i forget the rx architecture a whole esp32 module like https://www.lcsc.com/product-detail/Development-Boards-Kits_LCKFB-LCKFB-ESP32S3R8N8_C20626143.html https://www.lcsc.com/product-detail/Development-Boards-Kits_... is cheaper and has more ram though. that one has 8 megs of psram and costs usd4.93