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C6747 EMIFA to FIFO

Other Parts Discussed in Thread: SN74V215

Hi all,

I am trying to interface a C6747 Spectrum Digital EVM to our daughter board with an ADC.  The ADC feeds data to a SN74V215 FIFO which I am then trying to read via the EMIFA.  It mostly works but I am getting bit errors.  I suspect that the problem is the way that I have the FIFO configured to the EMIFA.  Right now I have:

FIFO /OE     = EMIFA /CS + EMIFA /OE

FIFO RCLK = EMIFA /CS + EMIFA /OE

FIFO /REN = GND (i.e. reads always enabled)

I've tried following the information in spra543.pdf about interfacing an asynchronous EMIF to a FWFT synchronous FIFO but the C6747 doesn't seem to have the /RE signal that is available for the older DSPs (spra543 discusses C6201/C6701).  Does anyone know how to do this for a C6747?

Thanks,

Lori

  • Lori,

    That appnote is 11 years old so you may need to double-check the signal descriptions between C6747 and the original C6000 that the appnote was based on.  Looking at the C6201 EMIF description for /ARE, I see:

    /ARE  Read enable—active low during a read transfer strobe period. Although not used for standard ASRAM interface, still used logically to determine when the data is read by the EMIF.

    Looking at the C6747 EMIF description for /EMA_OE, I see:

    EMA_OE Active-low pin enable for asynchronous devices. This pin provides a signal which is active-low during the strobe period of an asynchronous read access cycle.

    To me, it looks like you could substitute EMA_OE on C6747 for /ARE on C6201.

    -Tommy