Forum Discussion
Occasional ContributorMax10 programming external flash
After much trial and error, I have it working. Now I can write to and read from/erase the memory. Basically, I found and error in the Intel example design. Once I corrected it, everything works.
For anyone else who might try it using Nios.
First you have to do a write enable like this:
IOWR(EXT_FLASH_AVL_CSR_BASE,0x7,0x00000006);
IOWR(EXT_FLASH_AVL_CSR_BASE,0x8,0x1);then you can write 0xabcd1234 into the memory like this(this is where the example design had mistakes):
IOWR(EXT_FLASH_AVL_MEM_BASE,0x00000000,0xabcd1234);Then to read it back, do it like this:
IOWR(EXT_FLASH_AVL_CSR_BASE,0x4,0x00000000);
IOWR(EXT_FLASH_AVL_CSR_BASE,0x0,0x00000101);
IOWR(EXT_FLASH_AVL_CSR_BASE,0x5,0x00000003);
return IORD(EXT_FLASH_AVL_MEM_BASE,0x00000000);The most confusing parts are these offsets 0x4, 0x5....etc. I have figured out what most of them are, so I will list them below:
0x0 control register
0x4 operating protocols
0x5 read instructions
0x6 write instructions
0x7 flash command setting
0x8 flash command control(basically always write 0x1 here when writing into the status registers to begin the operation)
0x9 flash command address register
0xA flash command write data
0xC flash command read data
Why this isnt included in any documentation I have no idea. Basically, once I understood what these offsets were doing I had it up and running in just a few minutes. Hopefully these short notes help the next person.
Regular ContributorI think first of all, you need to do some setup before you run the TCL script. I would suggest you to source the TCL file first, then only execute the function. Copying the entire function wont work in system console.
You may refer to our system console user guide for the usage:
Occasional ContributorThank you YuanLi_S.
That user guide does help but, i am still having some issues with writing and reading to the memory..
I was able to verify the clock and the jtag loop using the system console. So I can now at least communicate with my system through the system console. Here is my qsys, HDL, and pinout for reference.
The only purpose of this build is to program the external flash chip(from Winbond).
So, now I am trying to write and read from the external flash memory just a list of byte values using the commands listed in the user guide. My code:
set master_path [lindex [get_service_paths master] 0]
open_service master $master_path
set values [list 0xaa 0xff 0xaa 0xff]
master_write_memory $master_path 0x00000000 $values
master_read_memory $master_path 0x00000000 4
I also tried using the addressing from the bursting master in Qsys:
master_write_memory $master_path 0x00800000 $values
master_read_memory $master_path 0x01000120 4
Results:
If I read first, I can read from 0x00000000 and get some bytes back. They are not bytes which I placed there. When I then write to 0x00000000 it seems to go fine, but when i read again it locks up the system and i need to start over.
using the bursting master addressing:
I can write to 0x00800000 and it seems to work fine, but when reading from 0x01000120 I just get 0x00 0x00 0x00 0x00 in return.
So, I am not fully understanding how this read/write operation should work. It seems like it should be pretty simple but it just isn't working for me.
I think this simple write/read is the first step towards understanding how to flash the board with a larger file.
Thank you,
Jacob
- Jacob11
As another test, I removed the serial flash controller and replaced it with an on chip RAM.
Did a write and read with no issues. It is just something to do with this external ram.
So, i am understanding how to work with the system console, but something is wrong in either my qsys or it's a hardware issue.
