TM4C129ENCPDT: Other microcontrollers forum

Hi Akhilesh,

Can you take a look at Tools->ROV->Tasks->Detailed to see how big your tasks stacks are? Do you happen to have the buffer of size 512 or 4096 as a local variable? If so, when you increase from 512->4096, I expect you need to increase your task stack size also (or make the buffer a global or alloc it).

Note: I'm suspecting this because we initialize task stacks with 0xbebebebe.

Todd

Hi Todd,

I resolved this issue. Let me understand if I am doing right.

What I did is I changed the buffer size in ffconf.h. The FATfs I am using is from ti rtos. So I had to rebuild the ti rtos components in order to make these changes effective. When I rebuilt it, it is working fine. But again I have a few doubts.

1. Now that I am using a buffer size of 4096 as this is the sector size of my flash. What will happen every time if the buffer which I am going to write in some file say xyz.txt is less than 4096? In the end, whatever the size of the buffer, we can only write 256B at a time (as seen from the datasheet of flash). So, I am breaking the buffer of 4096 into 16 parts and writing it one by one in the MX25FatFs_diskWrite() function. If the content to be written is less than 4096B, will it waste the extra space in the sector or what it will do? Because in the function MX25FatFs_diskWrite(), I am getting the sector number. I map this sector no to the address by multiplying it with 4096. 

for(ui32PageIdx = 0; ui32PageIdx < 16;
ui32PageIdx++)
{
MX66L51235FPageProgram((ui32BlockAddr + (ui32PageIdx * 256)), (flashBuf + (ui32PageIdx * 256)), 256);
} // this is what I am doing while writing. 

2. How the MX25FatFs_diskWrite() is getting the sector no? I am calling f_write/f_open/f_read and MX25FatFs_diskWrite/read etc gets the sector no? I mean how the whole system FATfs is working? Still, I am not able to figure it out. 

Thanks

Regards,

Akhilesh

Hi Todd, Can you explain 1st point?

Also, what if I want to use sdspi drivers for flash? Will that work? I tried the sample code on the evaluation board df-tm4c129x but the error was check jumper settings. I tried the example fatsdDK-tm4c129x from the resource explorer. 

Thanks

Akhilesh,

The SDSPI driver works on SD cards.

Regarding the first point, you need to work with FatFS vendor on this question.

Todd

Hi Todd,

Just a query, how will you suggest to me to read/write operation using ROM APIs on fatfs at a low level. 

1 more thing. I am attaching the screenshot also.

When I format the flash and start creating file and writing, I have some doubts about the no of free clusters and others. 

1. Volume size 537040504 clusters after calling  f_getfree(path, &fre_clust, &g_MX25Handle); 

I don't understand why it is showing such a large value.

2. During the debugging, I checked the value of FIlL ptr and those are in the screenshot attached.

- free_clust = 1463. Why??

- n_fatent = 4028. Is this because I have set the buffer size of 4096 and the total no of sectors is 4096? My csize is 1 i.e. 1 sector per cluster. 

- My volume base starts at sector 63. Why? It wastes a lot of space. (62*4KB).

- fatbase starts at 64. 

- dirbase starts at 66

-database starts at 70. Why? (Check the attached screenshots)

What is it doing from 0-63 sectors? 

Thanks