diff options
Diffstat (limited to 'host/lib/usrp')
| -rw-r--r-- | host/lib/usrp/dboard/db_rfx.cpp | 88 |
1 files changed, 78 insertions, 10 deletions
diff --git a/host/lib/usrp/dboard/db_rfx.cpp b/host/lib/usrp/dboard/db_rfx.cpp index c38b006b0..4a5786aa4 100644 --- a/host/lib/usrp/dboard/db_rfx.cpp +++ b/host/lib/usrp/dboard/db_rfx.cpp @@ -15,6 +15,8 @@ // along with this program. If not, see <http://www.gnu.org/licenses/>. // +static const bool rfx_debug = true; + // IO Pin functions #define POWER_UP (1 << 7) // Low enables power supply #define ANT_SW (1 << 6) // On TX DB, 0 = TX, 1 = RX, on RX DB 0 = main ant, 1 = RX2 @@ -39,6 +41,7 @@ #include <uhd/usrp/dboard_manager.hpp> #include <boost/assign/list_of.hpp> #include <boost/format.hpp> +#include <boost/math/special_functions/round.hpp> using namespace uhd; using namespace uhd::usrp; @@ -215,25 +218,85 @@ double rfx_xcvr::set_lo_freq( dboard_iface::unit_t unit, double target_freq ){ + if (rfx_debug) std::cerr << boost::format( + "RFX tune: target frequency %f Mhz" + ) % (target_freq/100e6) << std::endl; + //clip the input target_freq = std::clip(target_freq, _freq_range.min, _freq_range.max); + if (_div2[unit]) target_freq *= 2; - //load the registers - adf4360_regs_t regs; + //map prescalers to the register enums + static const uhd::dict<int, adf4360_regs_t::prescaler_value_t> prescaler_to_enum = map_list_of + (8, adf4360_regs_t::PRESCALER_VALUE_8_9) + (16, adf4360_regs_t::PRESCALER_VALUE_16_17) + (32, adf4360_regs_t::PRESCALER_VALUE_32_33) + ; - if (_div2[unit]) target_freq *= 2; - regs.divide_by_2_output = (_div2[unit])? - adf4360_regs_t::DIVIDE_BY_2_OUTPUT_DIV2 : - adf4360_regs_t::DIVIDE_BY_2_OUTPUT_FUND ; + //calculate the following values + // fvco = [P*B + A] * fref/R + // fvco*R/fref = P*B + A = N + int A, B, P, R; double N; + static const int + B_min = 3, B_max = 8191, + A_min = 0, A_max = 31, + P_min = 8, P_max = 32; + static const int + N_min = P_min*B_min + A_min, + N_max = P_max*B_max + A_max; + double ref_freq = this->get_iface()->get_clock_rate(unit); + double ratio = target_freq/ref_freq; + + for(R = 1; R < 11; R++){ + //increment R and see if this allows for a large enough N + N = ratio*R; + if (N < N_min) continue; + N = std::clip<double>(N, N_min, N_max); + break; + } - //TODO + //discover the best value for P, B, and A + BOOST_FOREACH(P, prescaler_to_enum.keys()){ + B = int(std::floor(N/P)); + if (B > B_max) continue; + B = std::clip(B, B_min, B_max); + A = boost::math::iround(N - P*B); + A = std::clip(A, A_min, A_max); + break; + } + //load the register values + adf4360_regs_t regs; + regs.core_power_level = adf4360_regs_t::CORE_POWER_LEVEL_10MA; + regs.counter_operation = adf4360_regs_t::COUNTER_OPERATION_NORMAL; + regs.muxout_control = adf4360_regs_t::MUXOUT_CONTROL_DLD; + regs.phase_detector_polarity = adf4360_regs_t::PHASE_DETECTOR_POLARITY_POS; + regs.charge_pump_output = adf4360_regs_t::CHARGE_PUMP_OUTPUT_NORMAL; + regs.cp_gain_0 = adf4360_regs_t::CP_GAIN_0_SET1; + regs.mute_till_ld = adf4360_regs_t::MUTE_TILL_LD_ENB; + regs.output_power_level = adf4360_regs_t::OUTPUT_POWER_LEVEL_3_5MA; + regs.current_setting1 = adf4360_regs_t::CURRENT_SETTING1_0_31MA; + regs.current_setting2 = adf4360_regs_t::CURRENT_SETTING2_0_31MA; + regs.power_down = adf4360_regs_t::POWER_DOWN_NORMAL_OP; + regs.prescaler_value = prescaler_to_enum[P]; + regs.a_counter = A; + regs.b_counter = B; + regs.cp_gain_1 = adf4360_regs_t::CP_GAIN_1_SET1; + regs.divide_by_2_output = (_div2[unit])? + adf4360_regs_t::DIVIDE_BY_2_OUTPUT_DIV2 : + adf4360_regs_t::DIVIDE_BY_2_OUTPUT_FUND ; + regs.divide_by_2_prescaler = adf4360_regs_t::DIVIDE_BY_2_PRESCALER_FUND; + regs.r_counter = R; + regs.ablpw = adf4360_regs_t::ABLPW_3_0NS; + regs.lock_detect_precision = adf4360_regs_t::LOCK_DETECT_PRECISION_5CYCLES; + regs.test_mode_bit = 0; + regs.band_select_clock_div = adf4360_regs_t::BAND_SELECT_CLOCK_DIV_8; //write the registers - std::vector<adf4360_regs_t::addr_t> addrs = list_of + std::vector<adf4360_regs_t::addr_t> addrs = list_of //correct power-up sequence to write registers (R, C, N) + (adf4360_regs_t::ADDR_RCOUNTER) (adf4360_regs_t::ADDR_CONTROL) (adf4360_regs_t::ADDR_NCOUNTER) - (adf4360_regs_t::ADDR_RCOUNTER) ; BOOST_FOREACH(adf4360_regs_t::addr_t addr, addrs){ this->get_iface()->write_spi( @@ -243,7 +306,12 @@ double rfx_xcvr::set_lo_freq( } //return the actual frequency - return target_freq; //TODO... and remember to check div2 + double actual_freq = double(P*B + A) * ref_freq / double(R); + if (_div2[unit]) actual_freq /= 2; + if (rfx_debug) std::cerr << boost::format( + "RFX tune: actual frequency %f Mhz" + ) % (actual_freq/100e6) << std::endl; + return actual_freq; } /*********************************************************************** |