Inside Sparten-II??? (BSCAN, CAPTURE, STARTUP...)

[aniketd]

bscan capture

what is the use of startup, bscan, capture blocks in SPARTAN-II FPGA?? (you can able to see those blocks from FPGA editor)
how to use them??? any information????
as it is not mentioned in data sheet

 

[Beetroots]

Loook for information on boundry scan testing on the Xilinx website.