diff options
Diffstat (limited to 'host/lib/usrp/usrp_e/dsp_impl.cpp')
| -rw-r--r-- | host/lib/usrp/usrp_e/dsp_impl.cpp | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/host/lib/usrp/usrp_e/dsp_impl.cpp b/host/lib/usrp/usrp_e/dsp_impl.cpp new file mode 100644 index 000000000..11d22d15f --- /dev/null +++ b/host/lib/usrp/usrp_e/dsp_impl.cpp @@ -0,0 +1,212 @@ +// +// 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/>. +// + +#include "usrp_e_impl.hpp" +#include "usrp_e_regs.hpp" +#include <uhd/usrp/dsp_props.hpp> +#include <uhd/utils/assert.hpp> +#include <boost/bind.hpp> +#include <boost/math/special_functions/round.hpp> + +#define rint boost::math::iround + +using namespace uhd; +using namespace uhd::usrp; + +/*********************************************************************** + * Helper Functions + **********************************************************************/ +static boost::uint32_t calculate_freq_word_and_update_actual_freq(double &freq, double clock_freq){ + UHD_ASSERT_THROW(std::abs(freq) < clock_freq/2.0); + static const double scale_factor = std::pow(2.0, 32); + + //calculate the freq register word + boost::uint32_t freq_word = rint((freq / clock_freq) * scale_factor); + + //update the actual frequency + freq = (double(freq_word) / scale_factor) * clock_freq; + + return freq_word; +} + +// Check if requested decim/interp rate is: +// multiple of 4, enable two halfband filters +// multiple of 2, enable one halfband filter +// handle remainder in CIC +static boost::uint32_t calculate_cic_word(size_t rate){ + int hb0 = 0, hb1 = 0; + if (not (rate & 0x1)){ + hb0 = 1; + rate /= 2; + } + if (not (rate & 0x1)){ + hb1 = 1; + rate /= 2; + } + return (hb1 << 9) | (hb0 << 8) | (rate & 0xff); +} + +static boost::uint32_t calculate_iq_scale_word(boost::int16_t i, boost::int16_t q){ + return (boost::uint16_t(i) << 16) | (boost::uint16_t(q) << 0); +} + +/*********************************************************************** + * RX DDC Initialization + **********************************************************************/ +void usrp_e_impl::rx_ddc_init(void){ + _rx_ddc_proxy = wax_obj_proxy::make( + boost::bind(&usrp_e_impl::rx_ddc_get, this, _1, _2), + boost::bind(&usrp_e_impl::rx_ddc_set, this, _1, _2) + ); +} + +/*********************************************************************** + * RX DDC Get + **********************************************************************/ +void usrp_e_impl::rx_ddc_get(const wax::obj &key, wax::obj &val){ + switch(key.as<dsp_prop_t>()){ + case DSP_PROP_NAME: + val = std::string("usrp-e ddc0"); + return; + + case DSP_PROP_OTHERS: + val = prop_names_t(); //empty + return; + + case DSP_PROP_FREQ_SHIFT: + val = _ddc_freq; + return; + + case DSP_PROP_CODEC_RATE: + val = MASTER_CLOCK_RATE; + return; + + case DSP_PROP_HOST_RATE: + val = MASTER_CLOCK_RATE/_ddc_decim; + return; + + default: UHD_THROW_PROP_GET_ERROR(); + } +} + +/*********************************************************************** + * RX DDC Set + **********************************************************************/ +void usrp_e_impl::rx_ddc_set(const wax::obj &key, const wax::obj &val){ + switch(key.as<dsp_prop_t>()){ + + case DSP_PROP_FREQ_SHIFT:{ + double new_freq = val.as<double>(); + _iface->poke32(UE_REG_DSP_RX_FREQ, + calculate_freq_word_and_update_actual_freq(new_freq, MASTER_CLOCK_RATE) + ); + _ddc_freq = new_freq; //shadow + } + return; + + case DSP_PROP_HOST_RATE:{ + //set the decimation + _ddc_decim = rint(MASTER_CLOCK_RATE/val.as<double>()); + _iface->poke32(UE_REG_DSP_RX_DECIM_RATE, calculate_cic_word(_ddc_decim)); + + //set the scaling + static const boost::int16_t default_rx_scale_iq = 1024; + _iface->poke32(UE_REG_DSP_RX_SCALE_IQ, + calculate_iq_scale_word(default_rx_scale_iq, default_rx_scale_iq) + ); + } + return; + + default: UHD_THROW_PROP_SET_ERROR(); + } +} + +/*********************************************************************** + * TX DUC Initialization + **********************************************************************/ +void usrp_e_impl::tx_duc_init(void){ + _tx_duc_proxy = wax_obj_proxy::make( + boost::bind(&usrp_e_impl::tx_duc_get, this, _1, _2), + boost::bind(&usrp_e_impl::tx_duc_set, this, _1, _2) + ); +} + +/*********************************************************************** + * TX DUC Get + **********************************************************************/ +void usrp_e_impl::tx_duc_get(const wax::obj &key, wax::obj &val){ + switch(key.as<dsp_prop_t>()){ + case DSP_PROP_NAME: + val = std::string("usrp-e duc0"); + return; + + case DSP_PROP_OTHERS: + val = prop_names_t(); //empty + return; + + case DSP_PROP_FREQ_SHIFT: + val = _duc_freq; + return; + + case DSP_PROP_CODEC_RATE: + val = MASTER_CLOCK_RATE; + return; + + case DSP_PROP_HOST_RATE: + val = MASTER_CLOCK_RATE/_duc_interp; + return; + + default: UHD_THROW_PROP_GET_ERROR(); + } +} + +/*********************************************************************** + * TX DUC Set + **********************************************************************/ +void usrp_e_impl::tx_duc_set(const wax::obj &key, const wax::obj &val){ + switch(key.as<dsp_prop_t>()){ + + case DSP_PROP_FREQ_SHIFT:{ + double new_freq = val.as<double>(); + _iface->poke32(UE_REG_DSP_TX_FREQ, + calculate_freq_word_and_update_actual_freq(new_freq, MASTER_CLOCK_RATE) + ); + _duc_freq = new_freq; //shadow + } + return; + + case DSP_PROP_HOST_RATE:{ + _duc_interp = rint(MASTER_CLOCK_RATE/val.as<double>()); + + // Calculate CIC interpolation (i.e., without halfband interpolators) + size_t tmp_interp = calculate_cic_word(_duc_interp) & 0xff; + + // Calculate closest multiplier constant to reverse gain absent scale multipliers + double interp_cubed = std::pow(double(tmp_interp), 3); + boost::int16_t scale = rint((4096*std::pow(2, ceil(log2(interp_cubed))))/(1.65*interp_cubed)); + + //set the interpolation + _iface->poke32(UE_REG_DSP_TX_INTERP_RATE, calculate_cic_word(_duc_interp)); + + //set the scaling + _iface->poke32(UE_REG_DSP_TX_SCALE_IQ, calculate_iq_scale_word(scale, scale)); + } + return; + + default: UHD_THROW_PROP_SET_ERROR(); + } +} |