AnsweredAssumed Answered

AD9957 RAM access failure

Question asked by john105 on Jan 17, 2011
Latest reply on Jan 31, 2011 by john105

I am attempting to write and read the internal RAM in the AD9957.  It is not working.  Here is my procedure:

 

1.  Set RAM Enable = 0.

2.  Drive RT pin low, then high.

3.  Write to RAM Segment Register 0:  RAM Address Step Rate = 1; RAM End Address = 3; RAM Start Address = 0; RAM Playback Mode = 4

4.  Set RT pin low, then high.

5.  Write 4 values, one a time, to address 0x16.

6.  Set RT pin low, then high.

7.  Read back 4 values, one a time, from address 0x16.

 

The four values that I read back in step 7 are all identical.  They match the last value that I attempted to write in step 5.

 

What could cause this behavior?

 

Thanks,

John

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