详细说明：软件无线电USRP v4.2版本硬件原理图，包括clock、debug board、fpga、interface、power等部分，有pdf、sch、ps等多种格式。

文件列表:
  USRP_REV_4_2
  ............\ChangeLog
  ............\clock.pdf
  ............\clock.ps
  ............\clock.sch
  ............\dboard.pdf
  ............\dboard.ps
  ............\dboard.sch
  ............\fpga.pdf
  ............\fpga.ps
  ............\fpga.sch
  ............\interface.pdf
  ............\interface.ps
  ............\interface.sch
  ............\power.pdf
  ............\power.ps
  ............\power.sch
  ............\usrp-bom.xls
  ............\usrp_mboard.bom
  ............\xy
  ............\..\bottom-assembly.pdf
  ............\..\bottom-assembly.pho
  ............\..\bottom.xy
  ............\..\camplus.rep
  ............\..\top-assembly.pdf
  ............\..\top-assembly.pho
  ............\..\top.xy