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Diffstat (limited to 'usrp/host/lib/db_dtt754.cc')
| -rw-r--r-- | usrp/host/lib/db_dtt754.cc | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/usrp/host/lib/db_dtt754.cc b/usrp/host/lib/db_dtt754.cc new file mode 100644 index 000000000..d78c5b328 --- /dev/null +++ b/usrp/host/lib/db_dtt754.cc @@ -0,0 +1,323 @@ +/* -*- c++ -*- */ +// +// Copyright 2008 Free Software Foundation, Inc. +// +// This file is part of GNU Radio +// +// GNU Radio 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 asversion 3, or (at your option) +// any later version. +// +// GNU Radio 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 GNU Radio; see the file COPYING. If not, write to +// the Free Software Foundation, Inc., 51 Franklin Street, +// Boston, MA 02110-1301, USA. + +#include <usrp/db_dtt754.h> +#include <db_base_impl.h> + +int +control_byte_1() +{ + int RS = 0; // 0 = 166.66kHz reference + int ATP = 7; // Disable internal AGC + return (0x80 | ATP<<3 | RS); +} + +int +control_byte_2() +{ + int STBY = 0; // powered on + int XTO = 1; // turn off xtal out, which we don't have + int ATC = 0; // not clear exactly, possibly speeds up or slows down AGC, which we are not using + + int c = 0xc2 | ATC<<5 | STBY<<4 | XTO; + return c; +} + +int +bandswitch_byte(float freq, float bw) +{ + int P5, CP, BS; + + if(bw>7.5e6) { + P5 = 1; + } + else { + P5 = 0; + } + + if(freq < 121e6) { + CP = 0; + BS = 1; + } + else if(freq < 141e6) { + CP = 1; + BS = 1; + } + else if(freq < 166e6) { + CP = 2; + BS = 1; + } + else if(freq < 182e6) { + CP = 3; + BS = 1; + } + else if(freq < 286e6) { + CP = 0; + BS = 2; + } + else if(freq < 386e6) { + CP = 1; + BS = 2; + } + else if(freq < 446e6) { + CP = 2; + BS = 2; + } + else if(freq < 466e6) { + CP = 3; + BS = 2; + } + else if(freq < 506e6) { + CP = 0; + BS = 8; + } + else if(freq < 761e6) { + CP = 1; + BS = 8; + } + else if(freq < 846e6) { + CP = 2; + BS = 8; + } + else { // limit is ~905 MHz + CP = 3; + BS = 8; + } + return (CP<<6 | P5 << 4 | BS); +} + +db_dtt754::db_dtt754(usrp_basic_sptr _usrp, int which) + : db_base(_usrp, which) +{ + /* + * Control custom DTT75403-based daughterboard. + * + * @param usrp: instance of usrp.source_c + * @param which: which side: 0 or 1 corresponding to RX_A or RX_B respectively + * @type which: int + */ + + // FIXME: DTT754 and DTT768 can probably inherit from a DTT class + + if(d_which == 0) { + d_i2c_addr = 0x60; + } + else { + d_i2c_addr = 0x62; + } + + d_bw = 7e6; + d_IF = 36e6; + + d_f_ref = 166.6666e3; + d_inverted = false; + + set_gain((gain_min() + gain_max()) / 2.0); + + bypass_adc_buffers(false); +} + +db_dtt754::~db_dtt754() +{ +} + +float +db_dtt754::gain_min() +{ + return 0; +} + +float +db_dtt754::gain_max() +{ + return 115; +} + +float +db_dtt754::gain_db_per_step() +{ + return 1; +} + +bool +db_dtt754::set_gain(float gain) +{ + assert(gain>=0 && gain<=115); + + float rfgain, ifgain, pgagain; + if(gain > 60) { + rfgain = 60; + gain = gain - 60; + } + else { + rfgain = gain; + gain = 0; + } + + if(gain > 35) { + ifgain = 35; + gain = gain - 35; + } + else { + ifgain = gain; + gain = 0; + } + pgagain = gain; + + _set_rfagc(rfgain); + _set_ifagc(ifgain); + _set_pga(pgagain); + + return true; // can't fail with the assert in place +} + +double +db_dtt754::freq_min() +{ + return 44e6; +} + +double +db_dtt754::freq_max() +{ + return 900e6; +} + +struct freq_result_t +db_dtt754::set_freq(double target_freq) +{ + /* + * @returns (ok, actual_baseband_freq) where: + * ok is True or False and indicates success or failure, + * actual_baseband_freq is the RF frequency that corresponds to DC in the IF. + */ + + freq_result_t ret = {false, 0.0}; + + if(target_freq < freq_min() || target_freq > freq_max()) { + return ret; + } + + double target_lo_freq = target_freq + d_IF; // High side mixing + + int divisor = (int)(0.5+(target_lo_freq / d_f_ref)); + double actual_lo_freq = d_f_ref*divisor; + + if((divisor & ~0x7fff) != 0) { // must be 15-bits or less + return ret; + } + + // build i2c command string + std::vector<int> buf(5); + buf[0] = (divisor >> 8) & 0xff; // DB1 + buf[1] = divisor & 0xff; // DB2 + buf[2] = control_byte_1(); + buf[3] = bandswitch_byte(actual_lo_freq, d_bw); + buf[4] = control_byte_2(); + + bool ok = usrp()->write_i2c(d_i2c_addr, int_seq_to_str (buf)); + + d_freq = actual_lo_freq - d_IF; + + ret.ok = ok; + ret.baseband_freq = actual_lo_freq; + + return ret; + +} + +bool +db_dtt754::is_quadrature() +{ + /* + * Return True if this board requires both I & Q analog channels. + * + * This bit of info is useful when setting up the USRP Rx mux register. + */ + + return false; +} + +bool +db_dtt754::spectrum_inverted() +{ + /* + * The 43.75 MHz version is inverted + */ + + return d_inverted; +} + +bool +db_dtt754::set_bw(float bw) +{ + /* + * Choose the SAW filter bandwidth, either 7MHz or 8MHz) + */ + + d_bw = bw; + set_freq(d_freq); + + return true; // FIXME: propagate set_freq result +} + +void +db_dtt754::_set_rfagc(float gain) +{ + assert(gain <= 60 && gain >= 0); + // FIXME this has a 0.5V step between gain = 60 and gain = 59. + // Why are there two cases instead of a single linear case? + float voltage; + if(gain == 60) { + voltage = 4; + } + else { + voltage = gain/60.0 * 2.25 + 1.25; + } + + int dacword = (int)(4096*voltage/1.22/3.3); // 1.22 = opamp gain + + assert(dacword>=0 && dacword<4096); + usrp()->write_aux_dac(d_which, 1, dacword); +} + +void +db_dtt754::_set_ifagc(float gain) +{ + assert(gain <= 35 && gain >= 0); + float voltage = gain/35.0 * 2.1 + 1.4; + int dacword = (int)(4096*voltage/1.22/3.3); // 1.22 = opamp gain + + assert(dacword>=0 && dacword<4096); + usrp()->write_aux_dac(d_which, 0, dacword); +} + +void +db_dtt754::_set_pga(float pga_gain) +{ + assert(pga_gain >=0 && pga_gain <=20); + if(d_which == 0) { + usrp()->set_pga (0, pga_gain); + } + else { + usrp()->set_pga (2, pga_gain); + } +} |