Dspic data memory issue

malik_123pk · Joined: 24 Jul 2010 Posts: 7

why cannot i save an array of 1000 elements for Dspic 30f4013 .

as soon as i define
int a[1000];
it gives me error that ram is full . but dspic have lot of memory then it

FvM · Joined: 27 Aug 2008 Posts: 2337 Location: Germany

Check the datasheet. 30F4013 has only 2 kB of SRAM.

malik_123pk · Joined: 24 Jul 2010 Posts: 7

ok i just checked it , i was referring to wrong datasheet of 30F family.
Thanks dear.

what you think , how can i over come the low SRAM problem
will u suggest me to use the program memory fro data storage or should i use the external EEPROM

but using external EEPROM might slow down the process , i wanted to implement about 5 different FIR filter with 80 taps.
may use a decimation filter as well.

and want to use the FFT on the data as well.

this all suggest the need of extra memroy and i have just 30f4013 , cannot change this processor ,

please suggest me what to do

Ttelmah · Joined: 11 Mar 2010 Posts: 19545

and yet you can add an external memory?.
Normally much easier to change the processor!.....
The limiting factor with EEPROM, is the 'write' speed. Takes perhaps 1000* longer then a write to other types of memory. Reads are not too bad. One suggestion, would be a FRAM. These have write speed limited only by the rate at which you can transfer the data, when driven by most PICs. Use an SPI version, and write times can easily be fractional uSec totals.

Best Wishes

malik_123pk · Joined: 24 Jul 2010 Posts: 7

Using PSV function of Dspic, I can get a little bit extra space. Yeah you are right, best option is to change the Processor, only if you have a shop nearby, else putting the demand and waiting for few weeks for a processor is not a good plan (I live in pakistan ). Hence, I have to work on this processor. Anyway lets see.