diff options
Diffstat (limited to 'host/lib/usrp')
| -rw-r--r-- | host/lib/usrp/dboard/db_sbx_version3.cpp | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/host/lib/usrp/dboard/db_sbx_version3.cpp b/host/lib/usrp/dboard/db_sbx_version3.cpp index bf5da0a6d..040bef12f 100644 --- a/host/lib/usrp/dboard/db_sbx_version3.cpp +++ b/host/lib/usrp/dboard/db_sbx_version3.cpp @@ -75,7 +75,6 @@ double sbx_xcvr::sbx_version3::set_lo_freq(dboard_iface::unit_t unit, double tar if(ref_freq <= 12.5e6) D = adf4350_regs_t::REFERENCE_DOUBLER_ENABLED; //increase RF divider until acceptable VCO frequency - //start with target_freq*2 because mixer has divide by 2 double vco_freq = target_freq; while (vco_freq < 2.2e9) { vco_freq *= 2; @@ -83,7 +82,7 @@ double sbx_xcvr::sbx_version3::set_lo_freq(dboard_iface::unit_t unit, double tar } //use 8/9 prescaler for vco_freq > 3 GHz (pg.18 prescaler) - adf4350_regs_t::prescaler_t prescaler = vco_freq > 3e9 ? adf4350_regs_t::PRESCALER_8_9 : adf4350_regs_t::PRESCALER_4_5; + adf4350_regs_t::prescaler_t prescaler = target_freq > 3e9 ? adf4350_regs_t::PRESCALER_8_9 : adf4350_regs_t::PRESCALER_4_5; /* * The goal here is to loop though possible R dividers, @@ -91,7 +90,7 @@ double sbx_xcvr::sbx_version3::set_lo_freq(dboard_iface::unit_t unit, double tar * (frac) dividers. * * Calculate the N and F dividers for each set of values. - * The loop exists when it meets all of the constraints. + * The loop exits when it meets all of the constraints. * The resulting loop values are loaded into the registers. * * from pg.21 @@ -155,7 +154,7 @@ double sbx_xcvr::sbx_version3::set_lo_freq(dboard_iface::unit_t unit, double tar regs.frac_12_bit = FRAC; regs.int_16_bit = N; regs.mod_12_bit = MOD; - regs.clock_divider_12_bit = boost::math::iround(1/pfd_freq * MOD / 2e-3 * 4); + regs.clock_divider_12_bit = std::max(1, int(std::ceil(400e-6*pfd_freq/MOD))); regs.feedback_select = adf4350_regs_t::FEEDBACK_SELECT_DIVIDED; regs.clock_div_mode = adf4350_regs_t::CLOCK_DIV_MODE_RESYNC_ENABLE; regs.prescaler = prescaler; |