AnsweredAssumed Answered

ADSP21479 AMI timing

Question asked by alevy on Mar 15, 2012
Latest reply on Mar 16, 2012 by Mitesh

Hi-

 

I'm trying to attach an FPGA to the ADSP-21479's AMI.  Looking at the hardware reference manual for the ADSP-214xx, in section 3 for the AMI, it says that the data for a read is sampled on the rising edge of the SDCLK at the beginning of the hold period (when the /AMI_RD line goes high).  The FPGA obviously doesn't have access to SDCLK, though, so how does it know when to tri-state the bus?  On the DSP's side, I can use the Idle Cycle (IC) bits in the AMICTL register to give the FPGA plenty of time to release the bus, but simply putting in a few clock cycle delays on the FPGA doesn't seem reliable.  Is there a better way?

 

On a related note, when the reference manual says "cycles," is that the time it takes to do one byte of data transfer, or one SDCLK period?

 

Thanks.

Outcomes