Ask HN: Getting through the steep learning barrier for hardware?

For those of you with hardware-centric jobs, how do you get around the steep learning barriers for mastering hardware? Case in point -- the PCIe specification is 1300 pages long and even just reading the Mindshare book means I'm looking at 600 pages before I'm able to do anything. The Xilinx AXI specification is about 300 pages long and dense; I reckon I'll need to read about 90 pages before I'm successful. It seems hardware just requires a ton of steep learning, do you have any tips on getting through this sort of stuff faster?