About PSZ Field of EIM_CSnGCR1 Register for i.MX6DL

[yuuki]

Dear all,

We want to use EIM I/F of i.MX6DL.

We have a question about PSZ Field of EIM_CSnGCR1 Registe.

<Question 1>
What kind of behavior does the setting of PSZ Field give for external device access?

<Question 2>
In the case of Async Fix Latency, Does this PSZ field affect it?

The following is explained with EIM_WAIT signal,
   "Some External devices may not use this input signal for ready state indication (fix latency without WAIT signal monitoring).
    For these devices EIM should be configured accordingly (see RFL, WFL, and PSZ field descriptions)."

And the following is explained with PSZ filed,
   "When working in fix latency mode WAIT signal from the external device is not being monitored,
    PSZ is used to determine if page boundary is reached and renewal of access is preformed."

We understand the PSZ determines if page boundary is reached and renewal of access is preformed.

However, According to the explanation of RFL and WFL fields.

   "When RFL=1 Burst access is terminated on page boundary and resume on the following page according
    to BL bit field configuration, because WAIT signal is not monitored from the external device."

   "When WFL=1 Burst access is terminated on page boundary and resume on the following page according
    to BL bit field configuration, because WAIT signal is not monitored from the external device."

I cannot understand it well.
When PSZ field is used, Is there the detailed explanation other than RM?

Best Regards,
Yuuki

[art · Accepted solution]

Q. What kind of behavior does the setting of PSZ Field give for external device access?

A. The PSZ field is only valid when the APR bit is set, switching on so-called Page Mode read access to an external memory device. In this mode, the address is changed for each data beat (unlike the synchronous burst mode), but the CS signal remains asserted until the whole page, whose size is defined by PSZ, is read.

Q. In the case of Async Fix Latency, Does this PSZ field affect it?

A. For all cases when the APR bit is 0, the PSZ field setting does not affect an external device access.

Q. When PSZ field is used, Is there the detailed explanation other than RM?

A. No, there is no other document, describing the EIM operation.

Have a great day,
Artur

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[yuuki]

art‌

Dear Artur-san,

Thank you for your support.
I was able to understand it.

The following is explained in "22.1.2.2 Asynchronous Page Read Mode" of Reference Manual.
I understood that this explanation was a mistake.

Best Regards,
Yuuki

[art]

Sorry, my previous explanation was wrong, just mixed up some field names. Actually, in both Page Access mode and Synchronous mode, the burst length is defined by the BL field value (so, there is no bug in the Reference Manual document), and the PSZ field defines the page size of an external memory device in Synchronous mode to define whether the synchronous burst crosses the page boundary and the burst should be re-generated.

Anyway, the PSZ value does not affect an asynchronous access.

Best Regards,
Artur