Need help...

For questions and comments on programming in general. And for any items that don't fit into the forums below.

Moderators: Benj, Mods

Post Reply
fish
Posts: 6
Joined: Sun Oct 19, 2008 11:18 am
Location: Somerset
Contact:

Need help...

Post by fish »

Hi,
I am looking for a way to use external EEPROM with an 18F series chip. Does anyone know if
a)there is an 80 pin chip that actually has EEPROM, or
b)if there is a way to communicate to an external EEPROM chip?

This is extremely annoying, as I need all the I/O's of the 18F series, but also with EEPROM. I understand that a few pins will need to go to EEPROM, and that is fine.

Any Help?

Thanks,
Conor(15)

Sean
Valued Contributor
Valued Contributor
Posts: 548
Joined: Tue Jun 26, 2007 11:23 am
Has thanked: 6 times
Been thanked: 44 times
Contact:

Re: Need help...

Post by Sean »

Hello Conor,

There are a small number of 80-pin, 18F serier PICs that contain EEPROM. Exmples are: 18F8520/8527/8622/8627/8722. Each provides 1K of EEPROM. If this is insufficient, or the devices are unsuitable for other reasons, external EEPROMs can be added via the I2C or SPI busses. SPI provided a higher data transfer but requies up to 4 port pins. The I2C bus is slower but requires only 2 port pins.

Both busses use internal hardware that is only available on specific port pins. Flowcode also provides a software implementation of the I2C bus that can be allocated to any available port pins.

fish
Posts: 6
Joined: Sun Oct 19, 2008 11:18 am
Location: Somerset
Contact:

Re: Need help...

Post by fish »

Thankyou Sean!!!
That is really helpful :)

Post Reply