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AM2631: AM2631: SDK GPMC sample code: Signal aligned to clk rising edge, is it possible to align to falling edge?

Javier Rico
Prodigy 70 points
Part Number: AM2631

Hello,

The GPMC sample code of SDK (am263x_09_01_00_41) has been modified to be in synchronous mode. I have seen that the signals change in the rising edge of the clk, except for the Chip Select, which can be customized to  either edge by using CFG_CS_GPMC_CONFIG2_J_J's CSEXTRADELAY. Is there a way to configure the edge activation for other signals like Output Enable, Wait? The device I want to communicate with, uses some signals in the rising edge and some others in the falling edge.

Regards,

Javier.

  • +1
    TI__Expert 3170 points

    Hi Javier,

    Similar to the CSEXTRADELAY there are fields like OEEXTRADELAY, ADVEXTRADELAY, WEEXTRADELAY which can be configured to 1h to delay the signal by half GPMC_FCLK clock cycle.


    OEEXTRADELAY can be configured in GPMC_CONFIG4 Register bit field 7. 

    We are currently updating the AM263x GPMC register descriptions and updated Register addendum will be released shortly.
    For more understanding on GPMC Configuration Registers, please refer to GPMC Registers section in GPMC chapter from AM243x TRM .GPMC IP is similar in AM243x and AM263x .Sorry for the inconvenience caused while going through the documentation.


    Regards,
    Rijohn

  • +1
    TI__Guru**** 196416 points

    HI Javier,

    You can use either rising edge of falling edge of WAIT signal. The IRQ interrupt is triggered by a rising edge or a falling edge of WAIT signal which is selected through PIN Polarity of GPMC_CONFIG[9] register.Other signals such as nCS, WEn, OEn are active LOW. 

    The NAND is an asynchronous device. The delay time and setup time are relative to CSn or WEn signals.

    For synchronous NOR flash mode, the delay and setup time are relative to first edge (rising) of clock signal.

  • 0 in reply to Rijohn Pius
    Prodigy 70 points

    Thanks, looking forward on seeing the Register addendum with the same format as the AM243x TRM GPMC Registers section; in the meantime will be using the AM243x one.

  • 0 in reply to QJ Wang
    Prodigy 70 points

    Thanks, it helps me setting up the WAIT characteristics.