i.MX Processorsのトピック flexspi memory map for M4 on iMX8-mini

flexspi memory map for M4 on iMX8-mini

jeff_hane — Tue, 30 Jul 2019 22:25:46 GMT

I need to use the flexspi to talk to an FPGA from the M4. Currently I'm use the NXP dev board to prototype this by having the M4 read/write data to the connected flash. From linux, I've written some data the the raw device /dev/mtd0 and can read it back with dd to verify it is correct.

Now I just want to memcpy that data and print it on the M4's console; however, it is unclear what the physical address of the flash is.

There is this info the RM:

10.2.4.10 Flash access by AHB Command
Flash could be accessed by AHB bus directly on AHB address space:0~0x10000000.
This address space is mapped to Serial Flash Memory in FlexSPI. AHB bus access to this
address space may trigger Flash access command sequence as needed.

The wording this is odd since it sounds like I could access the flash at address 0. This seems unlikely but I tried reading from address 0 but that data was not what was expected.

This table looked promising:

2.1.3 Cortex-M4 Memory Map

Start Address End Address Region Size Allocation
C000_0000 CFFF_FFFF FLASH 256MB QSPI

Not my data at that address either, This table has a mapping for QSPI r/w buffers but this is not for AHB which is what I want to use.

Anyone know the address from the M4 to access the flash of flexspi??

thanks,

jeff

Re: flexspi memory map for M4 on iMX8-mini

CarlosCasillas — Fri, 09 Aug 2019 22:56:14 GMT

Hi Jeff,

You could take a look to the following links for related information:

RT1050 FlexSPI

i.MX 8M-Mini QSPI booting on EVK Rev C

i.MX8 Boot process and creating a bootable image

https://community.nxp.com/docs/DOC-343104

Hope this will be useful for you.

Best regards!

/Carlos

Re: flexspi memory map for M4 on iMX8-mini

jeff_hane — Thu, 15 Aug 2019 17:52:56 GMT

Hi Carlos,

Thanks for the response but I didn't see anything helpful in these post. I eventually just tried the same address that the RM said is for the A53 and it work. So I don't really understand what the memory map table for the M4 is for.

jeff