Hello mauroscoccia,
Can you tell me what was the Read & Write burst length that you could get?
I use similar set-up like yours. I can read 16 words (16-bit) in a burst and write 4 words (16-bit) in a burst. Does this match with your end result?
Thanks,
Anuja
Hi mauro
https://community.nxp.com/docs/DOC-106467
also one can look at i.mx53 eim example and port it to i.mx6q
Sample code to use i.MX6DQ EIM burst access.
For porting may be useful baremetal sdk, it may be found on thread
Best regards
igor
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Hi igor,
just another information.
I performed some tests and I verified that between two consecutive accesses to the bus spend about 300 nsec.
Is this a normal operation of the bus, or do I make a wrong setup?
With those latencies the bus performance is much lower than expected.
The register setup used is the follows :
GCR1 is
GCR2 is
RCR1 is
RCR2 is
WCR1 is
WCR2 is
WCR is
WIAR is
Thank you.
Hi mauro
EIM timings are described in sect.4.9.3 External Interface Module (EIM)
i.MX6DQ Datasheet
http://www.nxp.com/docs/en/data-sheet/IMX6DQCEC.pdf
Best regards
igor
I saw the document you sent me, but unfortunately does not refer to the time between two consecutive accesses to the bus.
From My tests it would seem that there is this latency, but I do not know why and I can not find the way (if it exists) to decrease the latency values mentioned in the previous email.
Is it possible that these latencies are normal?
Can you help me?
Thank you.
Mauro.
Da: igorpadykov
Inviato: mercoledì 17 aprile 2019 12:44
A: Mauro Scoccia
Oggetto: Re: - Re: EIM Burst configuration
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Re: EIM Burst configuration
reply from igorpadykov<https://community.nxp.com/people/igorpadykov?et=watches.email.thread> in i.MX Processors - View the full discussion<https://community.nxp.com/message/1140562?commentID=1140562&et=watches.email.thread#comment-1140562>
one can run test with baremetal sdk example, it provides minimal latency.
Best regards
igor
time between two consecutive accesses to the eim bus is defined by
internal bus delays of processor, depends on overall processor loading.
In general you can not significantly decrease it. One can try to decrease
processor loading removing all other applications or increase master priority
using suggestions in Chapter 45 Network Interconnect Bus System (NIC-301)
i.MX6Q Reference Manual.
Best regards
igor