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Diffstat (limited to 'gnuradio-core/src/python/gnuradio/gruimpl/lmx2306.py')
| -rwxr-xr-x | gnuradio-core/src/python/gnuradio/gruimpl/lmx2306.py | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/gnuradio-core/src/python/gnuradio/gruimpl/lmx2306.py b/gnuradio-core/src/python/gnuradio/gruimpl/lmx2306.py new file mode 100755 index 0000000000..b46c896f73 --- /dev/null +++ b/gnuradio-core/src/python/gnuradio/gruimpl/lmx2306.py @@ -0,0 +1,186 @@ +#!/usr/bin/env python +# +# Copyright 2004 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 version 2, 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., 59 Temple Place - Suite 330, +# Boston, MA 02111-1307, USA. +# + +'''Control National LMX2306 based frequency synthesizer''' + +from gnuradio import gr +from gnuradio import eng_notation +from gnuradio.eng_option import eng_option +from optparse import OptionParser + +# bottom two bits of 21 bit word select which register to program + +R_REG = 0x0 +AB_REG = 0x1 +F_REG = 0x2 + +F_counter_reset = (1 << 2) +F_phase_detector_polarity = (1 << 7) + +F_LD_tri_state = (0 << 4) +F_LD_R_divider_output = (4 << 4) +F_LD_N_divider_output = (2 << 4) +F_LD_serial_data_output = (6 << 4) +F_LD_digital_lock_detect = (1 << 4) +F_LD_open_drain = (5 << 4) +F_LD_high = (3 << 4) +F_LD_low = (7 << 4) + +# F_default = F_LD_digital_lock_detect | F_phase_detector_polarity +F_default = F_LD_open_drain | F_phase_detector_polarity + +# +# 4 control pins: +# CE always high +# LE load enable. When LE goes high, data stored in the shift register +# is loaded into one of the three registers +# CLK data is clocked in on the rising edge +# DATA single data bit. Entered MSB first + +DB_CLK = (1 << 0) +DB_DATA = (1 << 1) +DB_LE = (1 << 2) +DB_CE = (1 << 3) + +class lmx2306 (object): + '''Control the National LMX2306 PLL''' + __slots__ = ['pp', 'shadow', 'fosc', 'r', 'step_size', 'verbose'] + def __init__ (self, fosc, step_size, which_pp = 0): + '''FOSC is the frequency of the reference oscillator, + STEP_SIZE is the step between valid frequencies, + WHICH_PP specifies which parallel port to use + ''' + self.pp = gr.make_ppio (which_pp) + self.shadow = DB_CE + self.pp.lock () + self.pp.write_data (self.shadow) + self.pp.unlock () + self.verbose = False + self._set_fosc (fosc) + self._set_step (step_size) + + + def program (self, r, a, b): + if self.verbose: + print "lmx2306: r = %d a = %d b = %d" % (r, a, b) + self.pp.lock () + self._write_word (F_REG | F_default | F_counter_reset) + self._write_word (R_REG | ((r & 0x3fff) << 2)) + self._write_word (AB_REG | ((a & 0x1f) << 2) | ((b & 0x1fff) << 7)) + self._write_word (F_REG | F_default) + self.pp.unlock () + + def set_freq (self, freq): + '''Set the PLL frequency to FREQ + + Return the actual freq value set. It will be rounded down to a + multiple of step_size + ''' + divisor = int (freq / self.step_size) + actual = divisor * self.step_size + (a, b) = self._compute_ab (divisor) + self.program (self.r, a, b) + return actual + + # ---------------------------------------------------------------- + + def _set_fosc (self, ref_oscillator_freq): + self.fosc = ref_oscillator_freq + + def _set_step (self, step_size): + r = int (self.fosc / step_size) + if r * step_size != self.fosc: + raise ValueError, "step_size is not a factor of self.fosc" + if r < 3 or r > 16383: + raise ValueError, "r is out of range" + self.r = r + self.step_size = step_size + + def _compute_ab (self, divisor): + b = divisor / 8 + a = divisor - (b * 8) + if b < 3 or b > 8191 or a > b: + raise ValueError, "Invalid divisor" + return (a, b) + + def _write_word (self, w): + for i in range(21): + if w & (1 << 20): + self._set_DATA_1 () + else: + self._set_DATA_0 () + w = (w << 1) & 0x0ffffff + self._set_CLK_1 () + self._set_CLK_0 () + self._set_LE_1 () + self._set_LE_0 () + + def _set_LE_0 (self): + self.shadow = self.shadow & ~DB_LE + self.pp.write_data (self.shadow) + + def _set_LE_1 (self): + self.shadow = self.shadow | DB_LE + self.pp.write_data (self.shadow) + + def _set_CLK_0 (self): + self.shadow = self.shadow & ~DB_CLK + self.pp.write_data (self.shadow) + + def _set_CLK_1 (self): + self.shadow = self.shadow | DB_CLK + self.pp.write_data (self.shadow) + + def _set_DATA_0 (self): + self.shadow = self.shadow & ~DB_DATA + self.pp.write_data (self.shadow) + + def _set_DATA_1 (self): + self.shadow = self.shadow | DB_DATA + self.pp.write_data (self.shadow) + +if __name__ == '__main__': + parser = OptionParser (option_class=eng_option) + parser.add_option ("-o", "--fosc", type="eng_float", default=32e6, + help="set reference oscillator freq to FREQ", metavar="FREQ") + parser.add_option ("-s", "--step-size", type="eng_float", default=10e3, + help="set the frequency step size to STEP_SIZE") + parser.add_option ("-f", "--freq", type="eng_float", default=430e6, + help="set VCO frequency to FREQ") + parser.add_option ("-v", "--verbose", action="store_true", default=False) + (options, args) = parser.parse_args () + + if options.verbose: + print "fosc = %s step = %s fvco = %s" % ( + eng_notation.num_to_str (options.fosc), + eng_notation.num_to_str (options.step_size), + eng_notation.num_to_str (options.freq)) + + lmx = lmx2306 (options.fosc, options.step_size) + lmx.verbose = options.verbose + + actual = lmx.set_freq (options.freq) + + if options.verbose: + print "fvco_actual = %s delta = %s" % ( + eng_notation.num_to_str (actual), + eng_notation.num_to_str (options.freq - actual)) |