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TMS570LS3137: EMIF Data Pin 7 jumps around during reads

David Cothran
Intellectual 300 points
Part Number: TMS570LS3137
Other Parts Discussed in Thread: HALCOGEN

Hello,

We have stable communication between the TMS570 and our External Asynchronous Memory over 16-bit Buffered, Non-Zero wait mode. However during a read data pin 7 seems to jump sporadically. Picture Below.

Any thoughts on what would be causing this? We have only the single Async EMIF interface with all others uninitialized/disabled. I would imagine during a read the TMS570 EMIF relinquishes control of the data pins but wanted to check if there were any configuration issues/considerations regarding this from the TMS570.

Note: Verified the pinmux was correct

Thanks,

David Cothran

  • 0
    TI__Guru**** 196206 points
    Hello David,

    The EMIF memory has to be configured as device type or strongly-ordered type using MPU. Couple things to try:
    1. Lower the EMIF clock
    2. Increase read hold/setup/strobe width for read

    On BGA package, EMIF_DATA[7] is close to EMIF clock signal, so the routing of those two signals on your PCB might be placed too close . Can you disable the EMIF_CLK output to check data[7]?
  • 0 in reply to QJ Wang
    Intellectual 300 points

    QJ,

    We verified that the EMIF Clk Signal was not being output on the board by verifying pinmux mmr29 was set (disabling the EMIF_CLK output). We also lowered the EMIF clock to 12 MHz (from 36 MHz) and maxed out all of our hold/setup/strobes via halcogen. We put a jumper on the TMS570 dev kit SDRAM to ensure it was disabled but have also tried without it. We also verified the pinmux for ball pin k5 is set to EMIF_DATA[7].

    We noticed the pin is jumping during writes now as well. The pin is still jumping during reads.



    Let me know if you have any other suggestions.

    Thanks,
    David Cothran

  • 0 in reply to David Cothran
    TI__Guru**** 196206 points
    Hi David,

    From your waveform, the data D[7] is stable when WE and CS are asserted.
  • 0 in reply to QJ Wang
    Intellectual 300 points
    Thanks for your help and suggestions, the issue was a short across pins on the ASYNC chip. After cleaning the rosin it worked perfectly.

    Thanks again,
    David Cothran