FlexSPI for Flash & RAM (IMXRT106x)

[bw1]

Our team is using an IMXRT1062 with flash on FlexSPIA1, and wants to add external RAM.  They would like to memory map the external RAM and use it basically the same as internal RAM.  We are hoping to place QSPI RAM on FlexSPIB1. 

1) Is it possible use it RAM on B1 at execution speeds with all memory mapped RAM addressing while also executing code from flash on FlexSPIA1?  So not just IP bus commands. 

I understand that both can't run at the exact same time. 

2) If I am reading the reference manual correctly, A1 and B1 share the same LUT, so we would need commands for both in that same table? 

[powerfeatherdev]

Hi @bw1 , were you able to make this work? From what I understand from your original question, you were asking about connecting both an QSPI Flash and RAM on *both* channels (A&B) of the *same* FlexSPI instance (FlexSPI 1), correct?

If so, this confuses me as while @jingpan  says such a setup is possible, this other answer
from @victorjimenez says it's not.

[bw1]

@powerfeatherdev 
We ended up not completing that investigation, and did not get it functional during the development.  I was under the impression that it should be possible, but it is probably easier to have them on separate buses. 

[powerfeatherdev]

Thanks for the reply. Unfortunately the reason I ask is because the part we are currently looking at only has one FlexSPI, and I was wondering if this was feasible. Maybe we also need to move on to a bigger part...

[jingpan]

Hi @bw1 ,

1. Is it possible use it RAM on B1 at execution speeds with all memory mapped RAM addressing while also executing code from flash on FlexSPIA1? 

Yes, it's possible.

2. If I am reading the reference manual correctly, A1 and B1 share the same LUT, so we would need commands for both in that same table? 

Yes, in same LUT table. But A1 and B1 has standalone r/w command pointer to the LUT.

Regards,

Jing