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//
// 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 "usrp2_impl.hpp"
#include "usrp2_regs.hpp"
#include <uhd/usrp/dsp_props.hpp>
#include <uhd/utils/assert.hpp>
#include <boost/format.hpp>
#include <boost/bind.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/math/special_functions/round.hpp>
using namespace uhd;
using namespace uhd::usrp;
static const size_t default_decim = 16;
static const size_t default_interp = 16;
#define rint boost::math::iround
template <class T> T log2(T num){
return std::log(num)/std::log(T(2));
}
/***********************************************************************
* DDC Helper Methods
**********************************************************************/
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);
}
template <class rate_t> static rate_t
pick_closest_rate(double exact_rate, const std::vector<rate_t> &rates){
rate_t closest_match = rates.at(0);
BOOST_FOREACH(rate_t possible_rate, rates){
if(std::abs(exact_rate - possible_rate) < std::abs(exact_rate - closest_match))
closest_match = possible_rate;
}
return closest_match;
}
void usrp2_impl::init_ddc_config(void){
//create the ddc in the rx dsp dict
_rx_dsp_proxy = wax_obj_proxy::make(
boost::bind(&usrp2_impl::ddc_get, this, _1, _2),
boost::bind(&usrp2_impl::ddc_set, this, _1, _2)
);
//initial config and update
_ddc_decim = default_decim;
_ddc_freq = 0;
update_ddc_config();
}
void usrp2_impl::update_ddc_config(void){
//set the decimation
_iface->poke32(U2_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(U2_REG_DSP_RX_SCALE_IQ,
calculate_iq_scale_word(default_rx_scale_iq, default_rx_scale_iq)
);
}
/***********************************************************************
* DDC Properties
**********************************************************************/
void usrp2_impl::ddc_get(const wax::obj &key, wax::obj &val){
switch(key.as<dsp_prop_t>()){
case DSP_PROP_NAME:
val = std::string("usrp2 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 = get_master_clock_freq();
return;
case DSP_PROP_HOST_RATE:
val = get_master_clock_freq()/_ddc_decim;
return;
default: UHD_THROW_PROP_GET_ERROR();
}
}
void usrp2_impl::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(U2_REG_DSP_RX_FREQ,
calculate_freq_word_and_update_actual_freq(new_freq, get_master_clock_freq())
);
_ddc_freq = new_freq; //shadow
}
return;
case DSP_PROP_HOST_RATE:{
double extact_rate = get_master_clock_freq()/val.as<double>();
_ddc_decim = pick_closest_rate(extact_rate, _allowed_decim_and_interp_rates);
update_ddc_config();
}
return;
default: UHD_THROW_PROP_SET_ERROR();
}
}
/***********************************************************************
* DUC Helper Methods
**********************************************************************/
void usrp2_impl::init_duc_config(void){
//create the duc in the tx dsp dict
_tx_dsp_proxy = wax_obj_proxy::make(
boost::bind(&usrp2_impl::duc_get, this, _1, _2),
boost::bind(&usrp2_impl::duc_set, this, _1, _2)
);
//initial config and update
_duc_interp = default_interp;
_duc_freq = 0;
update_duc_config();
}
void usrp2_impl::update_duc_config(void){
// 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(U2_REG_DSP_TX_INTERP_RATE, calculate_cic_word(_duc_interp));
//set the scaling
_iface->poke32(U2_REG_DSP_TX_SCALE_IQ, calculate_iq_scale_word(scale, scale));
}
/***********************************************************************
* DUC Properties
**********************************************************************/
void usrp2_impl::duc_get(const wax::obj &key, wax::obj &val){
switch(key.as<dsp_prop_t>()){
case DSP_PROP_NAME:
val = std::string("usrp2 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 = get_master_clock_freq();
return;
case DSP_PROP_HOST_RATE:
val = get_master_clock_freq()/_duc_interp;
return;
default: UHD_THROW_PROP_GET_ERROR();
}
}
void usrp2_impl::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(U2_REG_DSP_TX_FREQ,
calculate_freq_word_and_update_actual_freq(new_freq, get_master_clock_freq())
);
_duc_freq = new_freq; //shadow
}
return;
case DSP_PROP_HOST_RATE:{
double extact_rate = get_master_clock_freq()/val.as<double>();
_duc_interp = pick_closest_rate(extact_rate, _allowed_decim_and_interp_rates);
update_duc_config();
}
return;
default: UHD_THROW_PROP_SET_ERROR();
}
}
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