HD44780 is it programmable/OTP

Nov 07, 2007 3 Replies

I am wondering if this chip is a microcontroller or just PLD I have an LCD (LM16255) with it and OKI M5259 but I can't get it to init into 4-bit mode. I know some LCDs don't support 4 bit mode but I thought , those are only compatible with 44780. Any Ideas?



Thanks Sam.


It's a custom microcontroller with some glue logic like shift registers, latches and timing stuff. Take a look at the block a diagram in the datasheet to see what's there.

The OKI M5259 is not 44780 compatible, see the datasheet here:

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Dave.

Not sure what you are trying to accomplish, but Microchip and Atmel (and others, I'm sure) both offer microcontrollers with integrated LCD segment drivers (up to hundreds) if you are looking to make a custom LCD product.

The HD44780 probably has a ROM mask for the fonts, since most of the datasheets I've seen include a workflow for designing your own font and getting a batch of controllers made.

Ben Jackson AD7GD http://www.ben.com/

So more or less fixed application(s). I was wondering if maybe this one is loaded it with modified software without 4 bit support. Frustrated wasn't thinking clearly...... again.

I guess it is back to trying to use a shift reg for my getup.

Cheers.

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