Where can I get documetation of axi bus protocol?

I have to create verification enviorment for axi bus. Where can I get the spec or the protocil of the AXI bus?

http://infocenter.arm.com/help/topic/com.arm.doc.set.amba/index.html#specs

In reply to rajan passionate:

Documentation – Arm Developer

Where can I see the spec and the timing diagram?

In reply to saritr:

See this also, www.gstitt.ece.ufl.edu/courses/fall15/eel4720_5721/labs/refs/AXI4_specification.pdf

AMBA APB/AHB bus protocols will be nice to start with as they are less complex than AXI, See this GitHub for APB and AHB bus protocol UVM testbench, https://github.com/mayur13/UVMReference/tree/master/projects