ATTiny15L + RAM Memory

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Hi,

what's the cheapest and fasted way to add some RAM (128 Byte needed) to a ATTiny15L. I2C Devices or SPI Devises would be O.K but they should be pretty fast ( > 100kBits/sec). Does anyone know such a device?

Hava a look at my web page -> http://www.tobiscorner.at.tf

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I'd be tempted to use a different processor that already has enough SRAM.

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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SPI SRAM is actually a quite rare beast. I have seen plenty of SPI EEPROM or Flash around. The CDP68HC68R1 seems to be an SPI SRAM, but I have never tried it.

However, I did try the Ramtron SPI FRAM. It achieves SRAM speeds with the additional benefit of being non-volatile. I hihgly recommend it. However, it's not breadboard-friendly as it comes in SOIC only.

As for speed, SPI should work well above 100 kbps. I2C devices usually work at up to 100 or 400 kbps, so even that might be an option, depending on the device. However, an I2C SRAM seems an even rarer beast.

Let us know what you decide to do and how it turns out for you. I am curious.

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Ramtron has several chips, they are even novram, I²C and spi
spi goes up to 5MHz.

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How about SRAM+RTC? This isn't a rare beast. Look at STMicroelectronic Timekeeper series. M41T256Y has 32K SRAM, 400 KHz I2C and a calendar. However, it's price may be not so attractive, I guess.

Cats never lie. At least, they do this rarely.

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I think i'll try theese Ramtron FRAM. If that doesn't work, i have to change the Microcontroller...

Hava a look at my web page -> http://www.tobiscorner.at.tf

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I just don't get it. You are starting with an inexpensive, 8-pin microcontroller with limited resources.

Now you find you need more resources--namely some SRAM.

So your requested solution is an external storage device that would use 2-4 of the 6 available I/O.

For all criteria I can think of--application size, application speed, board space, ease of development, and cost--you would be much better off to pick a microcontroller model that has the resources you need. At least that's what I strive for in a microcontroller design--minimize the number of external subsystems; strive for a near-single-chip solution.

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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FRAM to add 128 bytes?

Do you really mean 128 bytes? Are you sure you haven't lost a 'K' somewhere? :?

Four legs good, two legs bad, three legs stable.

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No it's really for 128 BYTES (minimum). It would be used to store the information of an 128 Pixel CCD Line Array. And with a 4K FRAM i could store 32 Samples..

I have now decided to take an ATMega8 for my project. Because terms of speed, internal RAM and the TQFP Package is not really bigger than the DIP8 package.

Hava a look at my web page -> http://www.tobiscorner.at.tf