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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/>.
//
#ifndef INCLUDED_LIBUHD_USRP_DSP_UTILS_HPP
#define INCLUDED_LIBUHD_USRP_DSP_UTILS_HPP
#include <uhd/config.hpp>
#include <uhd/types/dict.hpp>
#include <uhd/utils/assert.hpp>
#include <uhd/types/stream_cmd.hpp>
#include <boost/cstdint.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/tuple/tuple.hpp>
#include <boost/math/special_functions/round.hpp>
namespace uhd{ namespace usrp{
namespace dsp_type1{
template <class T> T ceil_log2(T num){
return std::ceil(std::log(num)/std::log(T(2)));
}
/*!
* Calculate the rx mux word from properties.
* \param is_quadrature true if the subdev is complex
* \param is_iq_swapped true if the i and q are reversed
* \param the 32-bit rx mux control word
*/
static inline boost::uint32_t calc_rx_mux_word(
bool is_quadrature,
bool is_iq_swapped
){
boost::uint32_t rx_mux = 0;
if (is_quadrature){
rx_mux = (0x01 << 2) | (0x00 << 0); //Q=ADC1, I=ADC0
}else{
rx_mux = (0x11 << 2) | (0x00 << 0); //Q=ZERO, I=ADC0
}
if (is_iq_swapped){
rx_mux = (rx_mux << 2) | (rx_mux >> 2);
}
return rx_mux;
}
/*!
* Calculate the tx mux word from properties.
* \param is_iq_swapped true if the i and q are reversed
* \param the 32-bit tx mux control word
*/
static inline boost::uint32_t calc_tx_mux_word(bool is_iq_swapped){
boost::uint32_t tx_mux = 0x10;
if (is_iq_swapped){
tx_mux = (tx_mux << 4) | (tx_mux >> 4);
}
return tx_mux;
}
/*!
* Calculate the cordic word from the frequency and clock rate.
* The frequency will be set to the actual (possible) frequency.
*
* \param freq the requested frequency in Hz
* \param codec_rate the dsp codec rate in Hz
* \param the 32-bit cordic control word
*/
static inline boost::uint32_t calc_cordic_word_and_update(
double &freq,
double codec_rate
){
UHD_ASSERT_THROW(std::abs(freq) < codec_rate/2.0);
static const double scale_factor = std::pow(2.0, 32);
//calculate the freq register word
boost::uint32_t freq_word = boost::math::iround((freq / codec_rate) * scale_factor);
//update the actual frequency
freq = (double(freq_word) / scale_factor) * codec_rate;
return freq_word;
}
/*!
* Calculate the CIC filter word from the rate.
* 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
*
* \param rate the requested rate in Sps
* \return the 32-bit cic filter control word
*/
template <typename dsp_rate_type>
static inline boost::uint32_t calc_cic_filter_word(dsp_rate_type 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);
}
/*!
* Calculate the IQ scale factor word from I and Q components.
* \param i the I component of the scalar
* \param q the Q component of the scalar
* \return the 32-bit scale factor control word
*/
static inline boost::uint32_t calc_iq_scale_word(
boost::int16_t i, boost::int16_t q
){
return (boost::uint32_t(i) << 16) | (boost::uint32_t(q) << 0);
}
/*!
* Calculate the IQ scale factor word from the rate.
* \param rate the requested rate in Sps
* \return the 32-bit scale factor control word
*/
template <typename dsp_rate_type>
static inline boost::uint32_t calc_iq_scale_word(dsp_rate_type rate){
// Calculate CIC interpolation (i.e., without halfband interpolators)
dsp_rate_type tmp_rate = calc_cic_filter_word(rate) & 0xff;
// Calculate closest multiplier constant to reverse gain absent scale multipliers
double rate_cubed = std::pow(double(tmp_rate), 3);
boost::int16_t scale = boost::math::iround((4096*std::pow(2, ceil_log2(rate_cubed)))/(1.65*rate_cubed));
return calc_iq_scale_word(scale, scale);
}
/*!
* Calculate the stream command word from the stream command struct.
* \param stream_cmd the requested stream command with mode, flags, timestamp
* \param num_samps_continuous number of samples to request in continuous mode
* \return the 32-bit stream command word
*/
static inline boost::uint32_t calc_stream_cmd_word(
const stream_cmd_t &stream_cmd, size_t num_samps_continuous
){
UHD_ASSERT_THROW(stream_cmd.num_samps <= 0x3fffffff);
//setup the mode to instruction flags
typedef boost::tuple<bool, bool, bool> inst_t;
static const uhd::dict<stream_cmd_t::stream_mode_t, inst_t> mode_to_inst = boost::assign::map_list_of
//reload, chain, samps
(stream_cmd_t::STREAM_MODE_START_CONTINUOUS, inst_t(true, true, false))
(stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS, inst_t(false, false, false))
(stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE, inst_t(false, false, true))
(stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_MORE, inst_t(false, true, true))
;
//setup the instruction flag values
bool inst_reload, inst_chain, inst_samps;
boost::tie(inst_reload, inst_chain, inst_samps) = mode_to_inst[stream_cmd.stream_mode];
//calculate the word from flags and length
boost::uint32_t word = 0;
word |= boost::uint32_t((stream_cmd.stream_now)? 1 : 0) << 31;
word |= boost::uint32_t((inst_chain)? 1 : 0) << 30;
word |= boost::uint32_t((inst_reload)? 1 : 0) << 29;
word |= (inst_samps)? stream_cmd.num_samps : ((inst_chain)? num_samps_continuous : 1);
return word;
}
} //namespace dsp_type1
}} //namespace
#endif /* INCLUDED_LIBUHD_USRP_DSP_UTILS_HPP */
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