Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

PIC with Dram for storing analog data - any experiences?

Status
Not open for further replies.

klemm

Member level 1
Joined
May 16, 2002
Messages
36
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
199
PIC with Dram

Hi,

has someone experiences with pics (16f876 or 877) and external dram like
41464 for storing analog data?



Kind regards,

Klemm
 

Sobakava

Full Member level 6
Joined
Mar 27, 2002
Messages
350
Helped
8
Reputation
16
Reaction score
8
Trophy points
1,298
Activity points
3,346
RAM

I was in workshop of microchip. They told me to use new ROMless
PIC18F series with external synchronous memory interface but
I don't know the exact product name.
 

Bat

Member level 1
Joined
Dec 15, 2002
Messages
35
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
348
I've tried to do a such thing with a COP8 (National).
I get a chip from an old memory for 8086 (1bit * 1Mbit).

The problem is the refresh (obviously ... )
I would to use timer of COP8 to refresh DRAM with no µC overhead. I think it's possible but I have not tried that.

In fact, I begin with an IT that refresh some column of DRAM (2 or 3 for example). The overhead is minimum in this case.
It seems to work very good. In fact I can refresh the DRAM 10 time slower than nominal rate and it work ...
It's a bit strange ...

Another point is that it is a 1bit memory and the column and line adresses are multiplexed. So to put or get one byte, there are a lot of cycles ...

But I don't do a lot more, I have used that for getting CD-TEXT from a CD (and it work I get 1ko of text -- the same amount of data that the eniere COP8 contain) ... but the CD-ROM Player (Sony) died very few time after that ...
And I replaced it with another CD-ROM Player, but it can't retrieve CD-TEXT, so I have don't go further.

(Sorry for poor English)
 

ljmnunes

Junior Member level 3
Joined
Jun 28, 2001
Messages
29
Helped
4
Reputation
8
Reaction score
3
Trophy points
1,283
Location
Brazil
Activity points
158
Hi!


I found the attached file in the net but I'm not sure were...

I hope it will usefull :D

ljmnunes
 

S

sick_man

Guest
hello

hi after looking at the code above
i realise that with little work
it becomes a good inc file module to acces dram via all platroms of pic
using just a simple couple of buffers etc some logic too do control

then you can also bank quite a lot within the pic

and page it as fresh routines via bootblock system
and nvram

i think it will work with or without eeprom on board but eeprom avalible restricts the addresses you have

choosing some extranious logic en pin etc can eleviate the address range issues
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top