Microcontrollers with less than 512 bytes of (EEP)ROM - Page 1
Forum section: electronics / general

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: March 28, 2019, 07:34:23 am
content: Although I have seen some early PIC microcontrollers with internal ROM capacities of 256 bytes upwards, the smallest internal (EEP)ROM capacity for a current production microcontroller I have seen is the Atmel ATtiny4/5 which is at 512 bytes.Do you know of any current production microcontrollers with less than 512 bytes of internal (EEP)ROM?

author: oPossum
author_rank: Super Contributor
timestamp: March 28, 2019, 07:37:13 am
content: PIC10F200/204 256 words (384 bytes)PIC10F320 256 words (448 bytes)The earliest Microchip branded PICs had at least 512 words (768 bytes) of OTP ROM. They still make flash versions of those parts.

author: JPortici
author_rank: Super Contributor
timestamp: March 28, 2019, 08:00:17 am
content: EEPROM, not program memory.https://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1014use the filter in the eeprom column

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 28, 2019, 09:08:46 am
content: Quote from: Scratch.HTF on March 28, 2019, 07:34:23 amI'm sure you can find some, but they will be mature parts, that only a masochist would choose for a new design.The newest even 8 bit MCUs being released in 2019, like the new ML51 series from Nuvoton, do not bother going smaller than 16k Bytes, such are the price curves today.The recent N76E003AT20-T is $0.2123/5k+ with 18k Flash, so you see where the price curves are now.

author: westfw
author_rank: Super Contributor
timestamp: March 30, 2019, 03:36:28 am
content: Oh come on. Digikey's parametric search on "Microcontroller" shows 800+ currently in-stock chips with 224 bytes or less of EEPROM.While most of them are what I'd probably consider "legacy" devices (PIC16F84A is there!), it includes a bunch of modern AVR "Xtiny" (ie ATtiny412) and modern PIC16F chips (PIC16F15313) as well.(This does assume that you actually meant "EEPROM", rather than program memory (which is usually flash.))I don't know whether this URL will work:[size=78%]https://www.digikey.com/products/en/integrated-circuits-ics/embedded-microcontrollers/685?FV=48c0001%2C48c0002%2C48c0019%2C48c002b%2C48c0008%2Cffe002ad&quantity=0&ColumnSort=1000011&page=1&stock=1&nstock=1&k=microcontroller&pageSize=25&pkeyword=microcontroller

author: amyk
author_rank: Super Contributor
timestamp: March 30, 2019, 04:14:20 am
content: Yes. All the mask ROM ones. 0 is less than 512, right?

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 30, 2019, 09:34:14 am
content: Quote from: westfw on March 30, 2019, 03:36:28 amIf you read the OP carefully, it's clear they mean code storage, as they write'the smallest internal (EEP)ROM'and says 'I have seen is the Atmel ATtiny4/5 which is at 512 bytes'Note the brackets, and the Tiny4 has that much CODE memory.Flash isElectricallyErasableProgrammable Read only memory.

author: macboy
author_rank: Super Contributor
timestamp: March 31, 2019, 03:26:14 am
content: Quote from: PCB.Wiz on March 30, 2019, 09:34:14 amNo, FLASH is FLASH, and EEPROM is EEPROM. they are most definitely not the same, even if they superficially seem similar. A key point of the "electrically erasable" feature of EEPROM is that it is single byte erasable. FLASH is always erased in blocks, and as such is not referred to as "electrically erasable" in order to maintain the distinction.But I think you are right, the OP was probably referring to code memory.The smallest PIC I've used is 256 instruction words (384 bytes), and it was OTP not FLASH.

author: westfw
author_rank: Super Contributor
timestamp: March 31, 2019, 06:05:34 am
content: There are several current MSP430 with only 512 bytes of program memory (Flash or FRAM)The MSP430L092 has no user-programmable ROM at all (and operates at 0.9V!)

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 01, 2019, 03:58:45 pm
content: The Cypress FX1, FX2 (8051 core) and even FX3 (ARM core) don't actually embed any kind of ROM, EEPROM or FLASH that I know of. Only SRAM.Probably not what the OP had in mind, but yeah there are still MCUs out there that just only embed RAM.

author: ebastler
author_rank: Super Contributor
timestamp: April 02, 2019, 11:18:24 am
content: Quote from: SiliconWizard on April 01, 2019, 03:58:45 pmWouldn't it be nice if the OP popped back in occasionally, to provide feedback and let us know what he is really after?Scratch.HTF has never followed up on his original post, and has not been back for the better part of a week now. Maybe it's time to let this rest?Edit: Just had a look at ScratchHTF's profile, and the most recent 5 or 6 threads he has opened. No follow-up after the initial post, ever. Doesn't motivate me to respond when I come across his next topic...