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RM48L952: EMIF is not waiting for EMIF_nWAIT

Toni Kuikka
Prodigy 40 points
Part Number: RM48L952
Other Parts Discussed in Thread: HALCOGEN

Hello!

I am trying to configure RM48L952 ZWT EMIF so that EMIF would wait until EMIF_nWAIT is released by FPGA.

Here is a SignalTap II capture of the situation:

Signals are as follow:

ardy = pin P3 (EMIF_nWAIT)

nams3 = pin M17 (EMIF_NCS[4])

naoe = pin E12 (EMIF_nOE)

As you see from above capture, EMIF will not wait for the EMIF_nWAIT.

Here is my configureation from HALCOGen:

And here you can see EMIF configuration before capture picture:

So what I have configured to be wrong?

As far I know, all conditions for EMIF_nWAIT to work should be configured.

Address and other signals I can see to be correct. If I change EMIF configuration so that R_HOLD/STROBE/SETUP is long enough. I can see correct data on the Hercules.

Br,

Toni

  • 0
    TI__Guru**** 197036 points

    Hello,

    Your configuration is good. The setup time, hold time etc should meet the specification of the external memory. The TRM (spnu499b) says (page 622, chapter 17 EMIF):

    "Refer to the datasheet of the external asynchronous device to determine the appropriate setting for this field."

  • 0 in reply to QJ Wang
    Prodigy 40 points
    Hello,

    Thanks for a fast response!

    When is EMIF_nWAIT pin sampled by the EMIF? I was wondering this because as you see from capture, EMIF_nWAIT goes down little bit after EMIF_nOE. Is it possible that EMIF could think that EMIF_nWAIT is already up?

    Br,
    Toni
  • 0 in reply to Toni Kuikka
    TI__Guru**** 197036 points

    Toni,

    I did not use EMIF_nWait before. It should be ok for EMIF_nWait goes down little bit after OE. I am only concern with the setup time : tsu(EMWEL-EMWAIT). The minimum is 4E+30ns