Topic: problem during our test of FMC 230 board, help please  (Read 9876 times)

imegstore May 12, 2013, 11:00 AM

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We met a problem during our test of FMC 230 board.
The probem is as follows:
We can't write or read any registers on FMC230 board through SPI interface.
For example:
We try to read the register of 0x2 address in CPLD Register map, we get all zeros always.
It looks that SPI slave such as CPLD doens't respond correctly.
And we continue to check more on FMC230 board, it seems that the chip ADG3304 on FMC230 doesn't work well.
Our setting of ADG3304 is as:
  1) the pin of VCCA and EN is connected to 2.5V
  2) the pin of VCCY is connected to 3.3V
 
We try to access SPI interface from A side according to Figure 11 in FMC230 user manual,
   A1: chip select, active low
   A2: Clock
   A4: SDI/SDO interface
   
   And we check the signal at these 3pins, it is fine.
And we check signals on Y1, Y2, Y4, it should be of 3.3V level of signals, but there is wrong signals here.
   Y1: the CS's output is lower than 2.5V
   Y2: the clock's output is lower than 1V, and it is shifted by 1V or so.
   Y4: the output voltage is about 1.5 or even lower.
   
We don't know why these problems happen?  Is CPLD correctly programmed for tri-state control?
Or you can send new CPLD program used on FMC230 board to us to update.
Wish for urgent support from 4DSP team.