ICAP Virtex4 32 bits

Hi out there,

does anyone succeeded using ICAP_VIRTEX4 in 32 bit mode?

I have implemented a small ICAP controller hanging on the "B" side of a DPRAM. The ICAP is configured as 32 bits wide, but it does not work....

  1. If I assumed active low CE, and WE - the ICAP shows BUSY state - always... If I read whatever it presented on the 32 bit ports show: 0x0000009F. Does anyone know what this 9F is?

  1. If I assumed active high CE and WE, something got wiser: BUSY has started low, and went high only if I initiated an R or W ABORT. The next normal read will made it LOW again. It seems OK.

I have tried almost everything: bitorder reversing by octet and by 32 bits words. Change the Endianness. None. In this case the device can only present big fat zeroes..

Note1: I have changed the polarity of the CE/WE by using the FPGA editor

Note2: I have played the sequence:


read: ZERO (0x00000000) always....

Any idea?

Best regards,


Reply to
Meres Five
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I have successfully readback the IDCODE. It was a RAMB16 issue... It was in READ_FIRST mode, and that refired my state-machine, instead of dispatch/complete.

I have put it in WRITE_FIRST - and success!

Best regards

Reply to
Meres Five

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