Increase memory size

[haolian]

I'm designing a microcontroller embedded system using P89C51RC2 (8051 based with 4 i/o ports (8 bits)). I need to have a least 1 to 8 Mbytes of external memory for data storage. How can I do it at the lowest cost?
What type of memory shall i use? EEprom, CompactFlash, etc?


- I do not like to use too many address lines. I have 2 8bit ports used for LCD and keypads already. Can I use i2c interface? any suggestion for 1 to 8Mbytes memory expansion is welcome. Hopefully i do not need to use a 16bit controller.

 

[cbarn24050]

Hi, you are way out of a 8051's address range, whilst it is possible it would be very unsatisfactory. You need a micro with a 24bit address range. What kind of memory you need depends on your access requirements.

 

[haolian]

Hi! Thanks for the input. Just found serial flash of 4Mbits (potential of 64Mb).

http://www.nexflash.com/html/

Think I'm heading the right direction.

 

[electricuwe]

haolian,

to my mind you are on the right approach as long as you do not need to access your data with ahigh data rate. If speed is important I would suggest to follow chbarn24050 suggestion.

 

[felixc]

Atmel also has the "dataflash" which can go up to 128MB. Check if it can second-source your nexflash part. Or make a double overlapping footprint on your pcb, to make sure that you're not caught with a parts shortage.