What is a modern substitute for venerable EPROMs?

Question

Hi all,

I am doing some preliminary research for a possible project for next year. The project, in general terms, involves an embedded system with a uProcessor and external nonvolatile memory for firmware.

Over 20 years ago I worked with EPROMs; however, since we are now in the "Jetson" era, I wondered if there was a modern replacement for the EPROM.

I am aware of flash-able EEPROMs that can be programmed in circuit via software. I have flashed the BIOS on PCs using this technique. Also, this type of technology is at the core of the SSD, whether it is a 250GB device or a smaller 32GB USB thumb drive.

What sort of memory component can I use instead of the EPROM? Capacity can range from 8K to 32K. The device does not have to be pin compatible with the EPROMs. but should have similar functionality and be able to interface with either 3.3 or 5v devices (I am tending towards 5v).

Thank you for your time and assistance. Sgarciav

rachaelp · Answer

Hello, How about FRAM? Something like this: http://www.cypress.com/file/41731/download Best Regards, Rachael

jc2048 · Answer

You can still get parallel EEPROMS. This one is 32Kx8, 5V supply, and with 150nS access. Very similar to an EPROM. http://www.microchip.com/wwwproducts/en/AT28C256 Have a look around their memory section to see what else they've got.

pettitda · Answer

For storing firmware, flash memory is pretty much the modern equivalent of the EPROM. Most micro controllers include on-board flash memory of at least 32k up to 1M or more.

pettitda · Answer

I have personal experience with the Texas Instruments MSP430 line of micro controllers. They have a wide range of parts with varying peripheral sets, amounts of internal flash, and amounts of internal SRAM. However, there are many other vendors and product families that have internal flash. It just depends are what your requirements are.

johnbeetem · Answer

Salvador Garcia wrote:

I do have Yet Another Project that is shelved at the moment that will be using a microcontroller and I will be needing at least 64KB non volatile memory (internal to the uC). Could you reference a specific line or family of uControllers that have this internal flash memory? Thanks! Sgarciav

I like the STM32 parts from STMicroelectronics. They have a broad line of ARM Cortex parts with a wide range of price, performance, and power consumption. I've been programming the STM32F103C8 MCU which STM32 Discovery boards use as their ST-Link programming/debug processor. It has ARM Cortex-M3, 64KB Flash, 20KB SRAM, and a full-speed USB device interface along with the usual GPIOs, SPI, UARTs, etc. Very nice MCU. Good documentation, except for the USB section which badly needs rewriting.

I've never used ST's software -- I've done all development using FLOSS (Free-as-in-Liberty Open Source Software) tools over SWD ("Single Wire" Debug). So far, ST and ARM documentation have been complete enough to allow this.

There are other MCU vendors with similar capabilities. I'll let their fans make their own comments.

What is a modern substitute for venerable EPROMs?

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