aboutsummaryrefslogtreecommitdiffstats
path: root/host/lib/usrp/usrp_e/dsp_impl.cpp
blob: 11d22d15f6713223ec309e46a07719b14902b3b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
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();
    }
}