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Altera_Forum's avatar
Altera_Forum
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20 years ago

Multiple CPU or Nios II?

I'm working on a project that requires data to be read into a NIOS out of on chip FIFO. The data is then processed and stored onto a CF card. My problem is that their doesn't seem to b...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

Thanks for the ideas guys.

Right now though I am looking into my first idea of increasing the speed of writing to the CF card.

I went into the PTF file for the CF interface to adjust the timing for the card

and changed 

            Read_Wait_States = "530ns";
            Write_Wait_States = "500ns";
            Setup_Time = "70ns";
            Hold_Time = "30ns";

to 

            Read_Wait_States = "140ns";
            Write_Wait_States = "120ns";
            Setup_Time = "30ns";
            Hold_Time = "10ns";

and saw very little difference in write speed to the Flash Card (SLCF2GBJI).

the speed was approximately 800kb/s. Then for completeness of testing I slipped in a sandisk CF card (SDCFBI-2048-201-80) and ran the same test. I received drastically better speeds of approximately 1.8 MB/s. I rechecked my numbers, reran the tests, and had 2 other engineers verify my results and methods.

I checked the data sheets in which both say they can preform in mode 4 and the timings that are given in the data sheets are exactly the same as those in the CF.org specifications ver 3.0.

My first question is how do I convert "cycle time" and "-IORD/-IOWR" timing etc from the spec to the "Read_Wait_States" etc of the ptf file in nios

My second question is why would I be getting such different answers for two supposedly identical cards?

Thank you for your time

Steve