Overview
========

This branch includes changes to UHD to make it working with Fairwaves UmTRX hardware.

Among other changes it includes ICAP and other assorted FPGA timing issues:

26-JAN-2012: 
* Fix ICAP timing problems for UmTRX: the maximum clock rate for the ICAP module on the Spartan-6 FPGA is 20 MHz 
* Add a clk_icap to top level UmTRX design (13 MHz, 180 deg. phase clock generated by pll_clk.xco, a COREGEN module).
* Add pipeline registers pps signal in ./fpga/usrp2/timing/time_64bit.v
* Create ./fpga/usrp2/s6_icap_wb.v to clock Spartan-6 ICAP IP Core with clk_icap
* Modify ./fpga/usrp2/top/N2x0/u2plus_umtrx.v and u2plus_core.v to connect clk_icap (not connected for non-UmTRX designs)
* Change ISE tool settings based on smartXplorer parameters that meet timing and modify Makefile.UmTRX accordingly.

Implementation
==============

host/lib/usrp/dboard/db_lms.cpp - standard UHD description of UmTRX embedded dboard (including frequency range and so on).
host/lib/usrp/umtrx/* - implementation of UmTRX-specifix dboard interface and other classes.
host/lib/usrp/usrp2/usrp2_impl.hpp - common registration\detection functions shared with USRP2
host/lib/usrp/usrp2/usrp2_iface.hpp - also used in UmTRX
host/lib/usrp/usrp2/fw_common.h - place for shared protocol constants to communicate with ZPU
host/lib/usrp/umtrx/umtrx_impl.cpp - the place where SPI debug functions could be inserted into 
    so they are triggered upon multi_usrp init: for example reg_dump();
    
Testing
=======

Insert your SPI debug calls into usrp2_impl.cpp, run make in host/build/utils/ and run following command to trigger debug:
./usrp_burn_mb_eeprom --key hardware 2>&1 > test.out

This command will not modify anything on dboard or LMS unless specifically asked to in usrp2_impl.cpp

Notes
=====

If MAP fails when remaking the UmTRX FPGA bitstream under Ubuntu Linux for ISE v13.3 and below, define:

    LD_PRELOAD="$XILINX/lib/lin/libboost_serialization-gcc41-mt-p-1_38.so.1.38.0"

after sourcing the Xilinx settings and before issuing:

    make -f Makefile.UmTRX