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Altera_Forum
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15 years ago

Full On-Chip Memory

Hi, I'd like to know how to determine if the memory space of an on-chip memory is full. In my nios II system, I generated an on-chip M4K memory. It's size is 4096 bytes with a 32 bits data...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

You mean if you do this:

IOWR_32DIRECT(mem_1,0x0,(int)"THIS IS TO TEST HOW MUCH DATA CAN A MEMORY SPACE CONTAIN"); ?

It will try to store all that data in 4 bytes, which won't fit, so it will truncate the data as far as I know. Let me try :).

First clearing the memory to all 0x00 :

memset((void*)memory_base,0x00, memory_size)

and then using the following functions:

IOWR_32DIRECT(ALTMEMDDR_1_BASE,0x0,(int)"THIS IS TO TEST HOW MUCH DATA CAN A MEMORY SPACE CONTAIN");

int i;

for (i=0x0;i<0x20;i+=4)

{

printf("Address 0x%X: %x\n",(i+ALTMEMDDR_1_BASE),IORD_32DIRECT(ALTMEMDDR_1_BASE,i));

}

Gives (0xC being my ALTMEMDDR_1_BASE):

Address 0xC000000: 8030210

Address 0xC000004: 0

Address 0xC000008: 0

Address 0xC00000C: 0

Address 0xC000010: 0

Address 0xC000014: 0

Address 0xC000018: 0

Address 0xC00001C: 0

Hmm it's not even possible to store a string with this code or by using IOWR(ALTMEMDDR_1_BASE,0x0,(int)"IN") . But as you can see it will only store data in the first word.