diff options
Diffstat (limited to 'host/lib/usrp/dboard/db_tvrx.cpp')
| -rw-r--r-- | host/lib/usrp/dboard/db_tvrx.cpp | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/host/lib/usrp/dboard/db_tvrx.cpp b/host/lib/usrp/dboard/db_tvrx.cpp new file mode 100644 index 000000000..17fdad74a --- /dev/null +++ b/host/lib/usrp/dboard/db_tvrx.cpp @@ -0,0 +1,495 @@ +// +// Copyright 2010 Ettus Research LLC +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see <http://www.gnu.org/licenses/>. +// + +// No RX IO Pins Used + +// RX IO Functions + +//ADC/DAC functions: +//DAC 1: RF AGC +//DAC 2: IF AGC + +//min freq: 50e6 +//max freq: 860e6 +//gain range: [0:1dB:115dB] + +#include <uhd/utils/static.hpp> +#include <uhd/utils/assert.hpp> +#include <uhd/utils/algorithm.hpp> +#include <uhd/utils/warning.hpp> +#include <uhd/types/ranges.hpp> +#include <uhd/types/dict.hpp> +#include <uhd/usrp/subdev_props.hpp> +#include <uhd/usrp/dboard_base.hpp> +#include <uhd/usrp/dboard_manager.hpp> +#include <boost/assign/list_of.hpp> +#include <boost/format.hpp> +#include <boost/thread.hpp> +#include <boost/array.hpp> +#include <boost/math/special_functions/round.hpp> +#include <utility> +#include <cmath> +#include <cfloat> +#include <limits> +#include <tuner_4937di5_regs.hpp> + +using namespace uhd; +using namespace uhd::usrp; +using namespace boost::assign; + +/*********************************************************************** + * The tvrx constants + **********************************************************************/ +static const bool tvrx_debug = false; + +static const freq_range_t tvrx_freq_range(50e6, 860e6); + +static const prop_names_t tvrx_antennas = list_of("RX"); + +static const uhd::dict<std::string, freq_range_t> tvrx_freq_ranges = map_list_of + ("VHFLO", freq_range_t(50e6, 158e6)) + ("VHFHI", freq_range_t(158e6, 454e6)) + ("UHF" , freq_range_t(454e6, 860e6)) +; + +static const boost::array<double, 17> vhflo_gains_db = + {{-6.00000, -6.00000, -6.00000, -4.00000, 0.00000, + 5.00000, 10.00000, 17.40000, 26.30000, 36.00000, + 43.00000, 48.00000, 49.50000, 50.10000, 50.30000, + 50.30000, 50.30000}}; + +static const boost::array<double, 17> vhfhi_gains_db = + {{-13.3000, -13.3000, -13.3000, -1.0000, 7.7000, + 11.0000, 14.7000, 19.3000, 26.1000, 36.0000, + 42.7000, 46.0000, 47.0000, 47.8000, 48.2000, + 48.2000, 48.2000}}; + +static const boost::array<double, 17> uhf_gains_db = + {{-8.0000, -8.0000, -7.0000, 4.0000, 10.2000, + 14.5000, 17.5000, 20.0000, 24.5000, 30.8000, + 37.0000, 39.8000, 40.7000, 41.6000, 42.6000, + 43.2000, 43.8000}}; + +static const boost::array<double, 17> tvrx_if_gains_db = + {{-1.50000, -1.50000, -1.50000, -1.00000, 0.20000, + 2.10000, 4.30000, 6.40000, 9.00000, 12.00000, + 14.80000, 18.20000, 26.10000, 32.50000, 32.50000, + 32.50000, 32.50000}}; + +//gain linearization data +//this is from the datasheet and is dB vs. volts (below) +//i tried to curve fit this, but it's really just so nonlinear that you'd +//need dang near as many coefficients as to just map it like this and interp. +//these numbers are culled from the 4937DI5 datasheet and are probably totally inaccurate +//but if it's better than the old linear fit i'm happy +static const uhd::dict<std::string, boost::array<double, 17> > tvrx_rf_gains_db = map_list_of + ("VHFLO", vhflo_gains_db) + ("VHFHI", vhfhi_gains_db) + ("UHF" , uhf_gains_db) +; + +//sample voltages for the above points +static const boost::array<double, 17> tvrx_gains_volts = + {{0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0}}; + +static uhd::dict<std::string, gain_range_t> get_tvrx_gain_ranges(void) { + double rfmax = 0.0, rfmin = FLT_MAX; + BOOST_FOREACH(const std::string range, tvrx_rf_gains_db.keys()) { + double my_max = tvrx_rf_gains_db[range].back(); //we're assuming it's monotonic + double my_min = tvrx_rf_gains_db[range].front(); //if it's not this is wrong wrong wrong + if(my_max > rfmax) rfmax = my_max; + if(my_min < rfmin) rfmin = my_min; + } + + double ifmin = tvrx_if_gains_db.front(); + double ifmax = tvrx_if_gains_db.back(); + + return map_list_of + ("RF", gain_range_t(float(rfmin), float(rfmax), float((rfmax-rfmin)/4096.0))) + ("IF", gain_range_t(float(ifmin), float(ifmax), float((ifmax-ifmin)/4096.0))) + ; +} + +static const double opamp_gain = 1.22; //onboard DAC opamp gain +static const double tvrx_if_freq = 43.75e6; //IF freq of TVRX module +static const boost::uint16_t reference_divider = 640; //clock reference divider to use +static const double reference_freq = 4.0e6; + +/*********************************************************************** + * The tvrx dboard class + **********************************************************************/ +class tvrx : public rx_dboard_base{ +public: + tvrx(ctor_args_t args); + ~tvrx(void); + + void rx_get(const wax::obj &key, wax::obj &val); + void rx_set(const wax::obj &key, const wax::obj &val); + +private: + uhd::dict<std::string, float> _gains; + double _lo_freq; + tuner_4937di5_regs_t _tuner_4937di5_regs; + boost::uint8_t _tuner_4937di5_addr(void){ + return (this->get_iface()->get_special_props().mangle_i2c_addrs)? 0x61 : 0x60; //ok really? we could rename that call + }; + + void set_gain(float gain, const std::string &name); + void set_freq(double freq); + + void update_regs(void){ + byte_vector_t regs_vector(4); + + //get the register data + for(int i=0; i<4; i++){ + regs_vector[i] = _tuner_4937di5_regs.get_reg(i); + if(tvrx_debug) std::cerr << boost::format( + "tvrx: send reg 0x%02x, value 0x%04x" + ) % int(i) % int(regs_vector[i]) << std::endl; + } + + //send the data + this->get_iface()->write_i2c( + _tuner_4937di5_addr(), regs_vector + ); + } + +}; + +/*********************************************************************** + * Register the tvrx dboard + **********************************************************************/ +static dboard_base::sptr make_tvrx(dboard_base::ctor_args_t args){ + return dboard_base::sptr(new tvrx(args)); +} + +UHD_STATIC_BLOCK(reg_tvrx_dboard){ + //register the factory function for the rx dbid + dboard_manager::register_dboard(0x0040, &make_tvrx, "TVRX"); +} + +/*********************************************************************** + * Structors + **********************************************************************/ +tvrx::tvrx(ctor_args_t args) : rx_dboard_base(args){ + this->get_iface()->set_clock_enabled(dboard_iface::UNIT_RX, true); + + //set the gpio directions and atr controls (identically) + this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, 0x0); // All unused in atr + if (this->get_iface()->get_special_props().soft_clock_divider){ + this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, 0x1); // GPIO0 is clock + } + else{ + this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, 0x0); // All Inputs + } + + //send initial register settings if necessary + + //set default freq + _lo_freq = tvrx_freq_range.start() + tvrx_if_freq; //init _lo_freq to a sane default + set_freq(tvrx_freq_range.start()); + + //set default gains + BOOST_FOREACH(const std::string &name, get_tvrx_gain_ranges().keys()){ + set_gain(get_tvrx_gain_ranges()[name].start(), name); + } +} + +tvrx::~tvrx(void){ +} + +/*! Return a string corresponding to the relevant band + * \param freq the frequency of interest + * \return a string corresponding to the band + */ + +static std::string get_band(double freq) { + BOOST_FOREACH(const std::string &band, tvrx_freq_ranges.keys()) { + if(freq >= tvrx_freq_ranges[band].start() && freq <= tvrx_freq_ranges[band].stop()){ + if(tvrx_debug) std::cout << "Band: " << band << std::endl; + return band; + } + } + UHD_THROW_INVALID_CODE_PATH(); +} + +/*********************************************************************** + * Gain Handling + **********************************************************************/ +/*! + * Execute a linear interpolation to find the voltage corresponding to a desired gain + * \param gain the desired gain in dB + * \param db_vector the vector of dB readings + * \param volts_vector the corresponding vector of voltages db_vector was sampled at + * \return a voltage to feed the TVRX analog gain + */ + +static double gain_interp(double gain, boost::array<double, 17> db_vector, boost::array<double, 17> volts_vector) { + double volts; + gain = std::clip<double>(gain, db_vector.front(), db_vector.back()); //let's not get carried away here + + boost::uint8_t gain_step = 0; + //find which bin we're in + for(size_t i = 0; i < db_vector.size()-1; i++) { + if(gain >= db_vector[i] && gain <= db_vector[i+1]) gain_step = i; + } + + //find the current slope for linear interpolation + double slope = (volts_vector[gain_step + 1] - volts_vector[gain_step]) + / (db_vector[gain_step + 1] - db_vector[gain_step]); + + //the problem here is that for gains approaching the maximum, the voltage slope becomes infinite + //i.e., a small change in gain requires an infinite change in voltage + //to cope, we limit the slope + + if(slope == std::numeric_limits<double>::infinity()) + return volts_vector[gain_step]; + + //use the volts per dB slope to find the final interpolated voltage + volts = volts_vector[gain_step] + (slope * (gain - db_vector[gain_step])); + + if(tvrx_debug) + std::cout << "Gain interp: gain: " << gain << ", gain_step: " << int(gain_step) << ", slope: " << slope << ", volts: " << volts << std::endl; + + return volts; +} + +/*! + * Convert a requested gain for the RF gain into a DAC voltage. + * The gain passed into the function will be set to the actual value. + * \param gain the requested gain in dB + * \return dac voltage value + */ + +static float rf_gain_to_voltage(float gain, double lo_freq){ + //clip the input + gain = get_tvrx_gain_ranges()["RF"].clip(gain); + + //first we need to find out what band we're in, because gains are different across different bands + std::string band = get_band(lo_freq + tvrx_if_freq); + + //this is the voltage at the TVRX gain input + double gain_volts = gain_interp(gain, tvrx_rf_gains_db[band], tvrx_gains_volts); + //this is the voltage at the USRP DAC output + double dac_volts = gain_volts / opamp_gain; + + dac_volts = std::clip<double>(dac_volts, 0.0, 3.3); + + if (tvrx_debug) std::cerr << boost::format( + "tvrx RF AGC gain: %f dB, dac_volts: %f V" + ) % gain % dac_volts << std::endl; + + return float(dac_volts); +} + +/*! + * Convert a requested gain for the IF gain into a DAC voltage. + * The gain passed into the function will be set to the actual value. + * \param gain the requested gain in dB + * \return dac voltage value + */ + +static float if_gain_to_voltage(float gain){ + //clip the input + gain = get_tvrx_gain_ranges()["IF"].clip(gain); + + double gain_volts = gain_interp(gain, tvrx_if_gains_db, tvrx_gains_volts); + double dac_volts = gain_volts / opamp_gain; + + dac_volts = std::clip<double>(dac_volts, 0.0, 3.3); + + if (tvrx_debug) std::cerr << boost::format( + "tvrx IF AGC gain: %f dB, dac_volts: %f V" + ) % gain % dac_volts << std::endl; + + return float(dac_volts); +} + +void tvrx::set_gain(float gain, const std::string &name){ + assert_has(get_tvrx_gain_ranges().keys(), name, "tvrx gain name"); + if (name == "RF"){ + this->get_iface()->write_aux_dac(dboard_iface::UNIT_RX, dboard_iface::AUX_DAC_B, rf_gain_to_voltage(gain, _lo_freq)); + } + else if(name == "IF"){ + this->get_iface()->write_aux_dac(dboard_iface::UNIT_RX, dboard_iface::AUX_DAC_A, if_gain_to_voltage(gain)); + } + else UHD_THROW_INVALID_CODE_PATH(); + _gains[name] = gain; +} + +/*! + * Set the tuner to center the desired frequency at 43.75MHz + * \param freq the requested frequency + */ + +void tvrx::set_freq(double freq) { + freq = tvrx_freq_range.clip(freq); + std::string prev_band = get_band(_lo_freq - tvrx_if_freq); + std::string new_band = get_band(freq); + + double target_lo_freq = freq + tvrx_if_freq; //the desired LO freq for high-side mixing + double f_ref = reference_freq / double(reference_divider); //your tuning step size + + int divisor = int((target_lo_freq + (f_ref * 4.0)) / (f_ref * 8)); //the divisor we'll use + double actual_lo_freq = (f_ref * 8 * divisor); //the LO freq we'll actually get + + if((divisor & ~0x7fff)) UHD_THROW_INVALID_CODE_PATH(); + + //now we update the registers + _tuner_4937di5_regs.db1 = (divisor >> 8) & 0xff; + _tuner_4937di5_regs.db2 = divisor & 0xff; + + if(new_band == "VHFLO") _tuner_4937di5_regs.bandsel = tuner_4937di5_regs_t::BANDSEL_VHFLO; + else if(new_band == "VHFHI") _tuner_4937di5_regs.bandsel = tuner_4937di5_regs_t::BANDSEL_VHFHI; + else if(new_band == "UHF") _tuner_4937di5_regs.bandsel = tuner_4937di5_regs_t::BANDSEL_UHF; + else UHD_THROW_INVALID_CODE_PATH(); + + _tuner_4937di5_regs.power = tuner_4937di5_regs_t::POWER_OFF; + update_regs(); + + //ok don't forget to reset RF gain here if the new band != the old band + //we do this because the gains are different for different band settings + //not FAR off, but we do this to be consistent + if(prev_band != new_band) set_gain(_gains["RF"], "RF"); + + if(tvrx_debug) + std::cout << boost::format("set_freq: target LO: %f f_ref: %f divisor: %i actual LO: %f") % target_lo_freq % f_ref % divisor % actual_lo_freq << std::endl; + + _lo_freq = actual_lo_freq; //for rx props +} + +/*********************************************************************** + * Get the alias frequency of frequency freq when sampled at fs. + * \param freq the frequency of interest + * \param fs the sample rate + * \return the alias frequency + **********************************************************************/ + +static double get_alias(double freq, double fs) { + double alias; + freq = fmod(freq, fs); + if(freq >= (fs/2)) { + alias = fs - freq; + } else { + alias = freq; + } + return alias; +} + +/*********************************************************************** + * RX Get and Set + **********************************************************************/ +void tvrx::rx_get(const wax::obj &key_, wax::obj &val){ + named_prop_t key = named_prop_t::extract(key_); + double codec_rate; + + //handle the get request conditioned on the key + switch(key.as<subdev_prop_t>()){ + case SUBDEV_PROP_NAME: + val = get_rx_id().to_pp_string(); + return; + + case SUBDEV_PROP_OTHERS: + val = prop_names_t(); //empty + return; + + case SUBDEV_PROP_GAIN: + assert_has(_gains.keys(), key.name, "tvrx gain name"); + val = _gains[key.name]; + return; + + case SUBDEV_PROP_GAIN_RANGE: + assert_has(get_tvrx_gain_ranges().keys(), key.name, "tvrx gain name"); + val = get_tvrx_gain_ranges()[key.name]; + return; + + case SUBDEV_PROP_GAIN_NAMES: + val = prop_names_t(get_tvrx_gain_ranges().keys()); + return; + + case SUBDEV_PROP_FREQ: + /* + * so here we have to do some magic. because the TVRX uses a relatively high IF, + * we have to watch the sample rate to see if the IF will be aliased + * or if it will fall within Nyquist. + */ + codec_rate = this->get_iface()->get_codec_rate(dboard_iface::UNIT_RX); + val = (_lo_freq - tvrx_if_freq) + get_alias(tvrx_if_freq, codec_rate); + return; + + case SUBDEV_PROP_FREQ_RANGE: + val = tvrx_freq_range; + return; + + case SUBDEV_PROP_ANTENNA: + val = tvrx_antennas.front(); //there's only one + return; + + case SUBDEV_PROP_ANTENNA_NAMES: + val = tvrx_antennas; + return; + + case SUBDEV_PROP_CONNECTION: + val = SUBDEV_CONN_COMPLEX_IQ; + return; + + case SUBDEV_PROP_ENABLED: + val = true; //always enabled + return; + + case SUBDEV_PROP_USE_LO_OFFSET: + val = false; + return; + + case SUBDEV_PROP_LO_LOCKED: + val = true; + return; + + case SUBDEV_PROP_BANDWIDTH: + val = 6.0e6; + return; + + default: UHD_THROW_PROP_GET_ERROR(); + } +} + +void tvrx::rx_set(const wax::obj &key_, const wax::obj &val){ + named_prop_t key = named_prop_t::extract(key_); + + //handle the get request conditioned on the key + switch(key.as<subdev_prop_t>()){ + case SUBDEV_PROP_GAIN: + this->set_gain(val.as<float>(), key.name); + return; + + case SUBDEV_PROP_FREQ: + this->set_freq(val.as<double>()); + return; + + case SUBDEV_PROP_ENABLED: + return; //always enabled + + case SUBDEV_PROP_BANDWIDTH: + uhd::warning::post( + str(boost::format("TVRX: No tunable bandwidth, fixed filtered to 6MHz")) + ); + return; + + default: UHD_THROW_PROP_SET_ERROR(); + } +} + |