Program Memroy (PIC)

AtomSoft

Well-Known Member

• Jul 15, 2011

• #1

Ok i have some USB code but would love to implement a large buffer of 4096 bytes but i only have a 18F2550 which has 2048 ram

Is there anyway to use program memory as ram ? just asking im sure its not but heh

Im ordering: PIC24FJ64GB106 to fill my needs but would still love the answer

 

hexreader

Active Member

• Jul 15, 2011

• #2

Program memory can be written to, but whilst reading is fast, writing is really slow, which probably makes it useless for your purpose.

PIC18F2550 has "endurance" of 10k minimum (guaranteed) to 100k erase/write cycles, but use as RAM might soon exceed this figure.

You could add external SPI RAM, but even this will be limited in speed.

Upgrading to PIC24 or above looks like a good move to me. ...as long as you can cope with the move from 5V to 3.3V.

Hope this helps.

 

Last edited: Jul 15, 2011

AtomSoft

Well-Known Member

• Jul 15, 2011

• #3

Thanks a ton yeah. I assumed it would be a sacrifice, PIC24 is ok with me. 3.3v isnt a issue i can simply use a translator if needed

 

Last edited: Jul 15, 2011

be80be

Well-Known Member

• Jul 15, 2011

• #4

Atom a lot of pic 24 have 5 volt tolerable pins I would read some data sheets and find what you need.

 

AtomSoft

Well-Known Member

• Jul 15, 2011

• #5

Would need a full row (8 pins). A 74xx245 is cheap and comes in ssop so im ok with it

 

Last edited: Jul 15, 2011

AtomSoft

Well-Known Member

• Jul 15, 2011

• #6

Hey Burt can i get your thoughts:

https://www.electro-tech-online.com/threads/clones.120352/

 

be80be

Well-Known Member

• Jul 15, 2011

• #7

Here a good read https://www.electro-tech-online.com/custompdfs/2011/07/chap8_parport.pdf

 

AtomSoft

Well-Known Member

• Jul 15, 2011

• #8

Thanks a ton!