hi,
I am now doing a readback on the virtex2 device(xc2v1000). I have read the application note 138,139. But it's for virtex. I suppose it's the same with virtex2. I have still some question about it,
- Load the CFG_IN instruction into the JTAG IR, then go to SDR(shift data to register). I should first shift a sync word(aa995566)?
- the frame size to readback. for xc2v1000, one frame length is 3392 bit. I think it's same like virtex. For only one frame readback, It read back first the pad frame(3392 bit), then it's the frame we want.(3392 bit). so I think the frame size is 3392*2/32 = 212(d4h). is it right?
- How many times should I flush the command pipe? I think 2 times 32 bits of 0 are sent to flush the command pipe, because the JTAG register is 64 bit. is it right?
- Is there a pad word in front of frame?
I write the c code for readback. It's the command sequence ,
- 0xAA995566; Synchronization word
- 0x30002001; write to FAR register
- frame addr; from .ll file
- 0x30008001; write to CMD register
- 0x00000004; Active RCFG
- 0x280060d4; Number of word to readback (d4h = 212)
- 0x00000000; Flush command pipe with 32 bits of zeros.
- 0x00000000; Flush command pipe with 32 bits of zeros.
is that right?
Thank you for reading. Any information about it is welcome. Thanks in advance.
Wei