Hello,
the RT1020 flexspi_nor_polling_transfer demo project calls the function flexspi_nor_flash_init which gets the default config for flexspi and initializes most of the FlexSPI with default parameters.
The function GetDefaultConfig sets the Master IDs for all prefetch buffers to 0x0 because of the memset calls.
The RT1020 Reference Manual specifies in a note on page 1515
but I think that is exactly what the demo project/FLEXSPI_GetDefaultConfig function is doing.
Kind regards,
Stefan
Solved! Go to Solution.
Here is the reply from the A team and hope it can answer your inquiry.
That means the FlexSPI will still use only one buffer for single AHB master even assign multiple buffers to this master. The line in the RF is not clear.
Have a great day,
TIC
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Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
1) I'm working on the question now.
2-4) To provide the fastest possible support, I'd like to suggest you review the application note to learn the prefetch buffer impact of QSPI performance.
Have a great day,
TIC
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Thank you Jeremy, I read the application note. It is exactly like I thought. If there are a lot of jumps between different addresses it will have a lot of hit misses in AHB buffer which will decrease performance.
Unfortunately the application note did not answer my questions 2, 3 and 5 so I would appreciate your help for these too.
Kind regards,
Stefan
Hi,
Thanks for your reply.
2) The master 0 is no different from other Master IDs, it also is restricted by the configuration of the AHB RX Buffer Control Register.
3) Yes, it's okay to disable the Buffer[3].
5) After testing, the previous conclusion of https://community.nxp.com/thread/528725 is not correct actually.
Have a great day,
TIC
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Hello Jeremy,
thank you for your answer.
2) The master 0 is no different from other Master IDs, it also is restricted by the configuration of the AHB RX Buffer Control Register.
As I said:
the RT1020 flexspi_nor_polling_transfer demo project calls the function flexspi_nor_flash_init which gets the default config for flexspi and initializes most of the FlexSPI with default parameters.
The function GetDefaultConfig sets the Master IDs for all prefetch buffers to 0x0 because of the memset calls.
The RT1020 Reference Manual specifies in a note on page 1515
but I think that is exactly what the demo project/FLEXSPI_GetDefaultConfig function is doing.
It is not allowed to assign a master ID to multiple AHB buffers, why does the NXP driver assign all buffers to the AHB Master ID 0x0?
Kind regards,
Stefan
Hi,
Sorry for reply late because of Labor Day.
1) It is not allowed to assign a master ID to multiple AHB buffers, why does the NXP driver assign all buffers to the AHB Master ID 0x0?
-- Yes, it definitely makes the developers confused, and I'll contact the SDK software library team for confirmation.
Have a great day,
TIC
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Here is the reply from the A team and hope it can answer your inquiry.
That means the FlexSPI will still use only one buffer for single AHB master even assign multiple buffers to this master. The line in the RF is not clear.
Have a great day,
TIC
-------------------------------------------------------------------------------
Note:
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- We are following threads for 7 weeks after the last post, later replies are ignored
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Thank you!