Reading EPCS

[Altera_Forum]

Hello, I am trying to read data in EPCS by the following: 

== char buf[65535]; alt_flash_fd* epcs = alt_flash_open_dev(EPCS_FLASH_NAME); alt_epcs_flash_read(epcs, offset, buf, length); == I have tried various offsets & lengths, but buf is always filled with 0x14141414... I am booting my board from EPCS without any problem,  so I am sure this is not the right answer. Am I missing something? Thanks in advance.

[Altera_Forum]

This threat discussion below seems is demotrating the usage of the read and write EPCS as well. 

 http://www.alteraforum.com/forum/showthread.php?t=18461

[Altera_Forum]

Thanks, tony_stark. 

I did read the post, but still not working. I tried below: ==  static flash_region *p_epcs_reg_info;  static int num_epcs_regs;  alt_u8 buf[16];  alt_u8 buf2[16] = {0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F};  alt_flash_fd* epcs = alt_flash_open_dev(EPCS_FLASH_NAME);  int error = alt_epcs_flash_get_info(epcs, &p_epcs_reg_info, &num_epcs_regs);  alt_epcs_flash_erase_block(epcs,0);  alt_epcs_flash_write_block(epcs, 0, 0, (void*)buf2, 16);  alt_epcs_flash_read(epcs, 0, (void*)buf, 16); == As for p_epcs_reg_info & num_epcs_regs, I get below which seems OK: offset=0, region_size=2097152, number_of_blocks=32, block_size=65536, num_epcs_regs=1 I get error = 0, epcs is not NULL, so there seems to be no error. But I still get 0x14 for buf[0] to buf[15].. Is there anything else I should look for? Thanks in advance.

[Altera_Forum]

Did you check whether alt_flash_open_dev() returns a valid handle and if alt_epcs_flash_get_info() returns no error? 

Your posted code misses these points

[Altera_Forum]

Thanks Cris72, 

Yes, I did. As I wrote above,  == alt_flash_fd* epcs = alt_flash_open_dev(EPCS_FLASH_NAME); int error = alt_epcs_flash_get_info(epcs, &p_epcs_reg_info, &num_epcs_regs); == epcs was not NULL & error = 0

[Altera_Forum]

Hello, I found out my problem. 

I was not connecting nCS of EPCS properly. Assigned it to "nCSO" in my top module, but passing "n_CSO" to the lower module. I wonder why Quartus did not raise an error because "n_CSO" exists nowhere in my code... It was bit tricky to find out, because configuration works totally fine.  I was not aware that the problem could be on my FPGA side. Thanks,

[Altera_Forum]

--- Quote Start ---  Hello, I found out my problem. I was not connecting nCS of EPCS properly. Assigned it to "nCSO" in my top module, but passing "n_CSO" to the lower module. I wonder why Quartus did not raise an error because "n_CSO" exists nowhere in my code... It was bit tricky to find out, because configuration works totally fine.  I was not aware that the problem could be on my FPGA side. Thanks,  --- Quote End ---    good one! we all also never aware something not right with the FPGa and we focus on the software only :D