--- /dev/null
+/* -*- c++ -*- */
+//
+// Copyright 2008,2009 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.
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <usrp/db_dtt768.h>
+#include <db_base_impl.h>
+
+int
+control_byte_4()
+{
+ int C = 0; // Charge Pump Current, no info on how to choose
+ int R = 4; // 125 kHz fref
+
+ // int ATP = 7; // Disable internal AGC
+ return (0x80 | C<<5 | R);
+}
+
+int
+control_byte_5(float freq, int agcmode = 1)
+{
+ if(agcmode) {
+ if(freq < 150e6) {
+ return 0x3B;
+ }
+ else if(freq < 420e6) {
+ return 0x7E;
+ }
+ else {
+ return 0xB7;
+ }
+ }
+ else {
+ if(freq < 150e6) {
+ return 0x39;
+ }
+ else if(freq < 420e6) {
+ return 0x7C;
+ }
+ else {
+ return 0xB5;
+ }
+ }
+}
+
+int
+control_byte_6()
+{
+ int ATC = 0; // AGC time constant = 100ms, 1 = 3S
+ int IFE = 1; // IF AGC amplifier enable
+ int AT = 0; // AGC control, ???
+
+ return (ATC << 5 | IFE << 4 | AT);
+}
+
+int
+control_byte_7()
+{
+ int SAS = 1; // SAW Digital mode
+ int AGD = 1; // AGC disable
+ int ADS = 0; // AGC detector into ADC converter
+ int T = 0; // Test mode, undocumented
+ return (SAS << 7 | AGD << 5 | ADS << 4 | T);
+}
+
+db_dtt768::db_dtt768(usrp_basic_sptr _usrp, int which)
+ : db_base(_usrp, which)
+{
+ /*
+ * Control custom DTT76803-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
+ */
+
+ if(d_which == 0) {
+ d_i2c_addr = 0x60;
+ }
+ else {
+ d_i2c_addr = 0x62;
+ }
+
+ d_IF = 44e6;
+
+ d_f_ref = 125e3;
+ d_inverted = false;
+
+ set_gain((gain_min() + gain_max()) / 2.0);
+
+ bypass_adc_buffers(false);
+}
+
+db_dtt768::~db_dtt768()
+{
+}
+
+float
+db_dtt768::gain_min()
+{
+ return 0;
+}
+
+float
+db_dtt768::gain_max()
+{
+ return 115;
+}
+
+float
+db_dtt768::gain_db_per_step()
+{
+ return 1;
+}
+
+bool
+db_dtt768::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;
+}
+
+double
+db_dtt768::freq_min()
+{
+ return 44e6;
+}
+
+double
+db_dtt768::freq_max()
+{
+ return 900e6;
+}
+
+struct freq_result_t
+db_dtt768::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(6);
+ buf[0] = (divisor >> 8) & 0xff; // DB1
+ buf[1] = divisor & 0xff; // DB2
+ buf[2] = control_byte_4();
+ buf[3] = control_byte_5(target_freq);
+ buf[4] = control_byte_6();
+ buf[5] = control_byte_7();
+
+ 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_dtt768::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_dtt768::spectrum_inverted()
+{
+ /*
+ * The 43.75 MHz version is inverted
+ */
+
+ return d_inverted;
+}
+
+bool
+db_dtt768::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_dtt768::_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_dtt768::_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_dtt768::_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);
+ }
+}
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