TwinRX: Enable phase resync on ADF535x

1 files changed, 9 insertions, 17 deletions

diff --git a/host/lib/include/uhdlib/usrp/common/adf535x.hpp b/host/lib/include/uhdlib/usrp/common/adf535x.hpp
index 5ae92c3ef..3c05890f1 100644
--- a/host/lib/include/uhdlib/usrp/common/adf535x.hpp
+++ b/host/lib/include/uhdlib/usrp/common/adf535x.hpp
@@ -91,7 +91,7 @@ public:
           _wait_time_us(0),
           _ref_freq(0.0),
           _pfd_freq(0.0),
-          _fb_after_divider(false)
+          _fb_after_divider(true)
   {
 
     _regs.vco_band_div = 3;
@@ -103,14 +103,10 @@ public:
     _regs.adc_conversion = adf535x_regs_t::ADC_CONVERSION_ENABLED;
     _regs.adc_enable = adf535x_regs_t::ADC_ENABLE_ENABLED;
 
-    // TODO Needs to be enabled for phase resync
+    // Start with phase resync disabled and enable when reference clock is set
     _regs.phase_resync = adf535x_regs_t::PHASE_RESYNC_DISABLED;
 
-    // TODO Default should be divided, but there seems to be a bug preventing that. Needs rechecking
-    _regs.feedback_select = adf535x_regs_t::FEEDBACK_SELECT_FUNDAMENTAL;
-
-    // TODO 0 is an invalid value for this field. Setting to 1 seemed to break phase sync, needs retesting.
-    _regs.phase_resync_clk_div = 0;
+    set_feedback_select(FB_SEL_DIVIDED);
   }
 
   ~adf535x_impl() override
@@ -163,7 +159,7 @@ public:
     }
 
     //Reference divide-by-2 for 50% duty cycle
-    // if R even, move one divide by 2 to to regs.reference_divide_by_2
+    // if R even, move one divide by 2 to regs.reference_divide_by_2
     const bool div2_en = (ref_div_factor % 2 == 0);
     if (div2_en) {
       ref_div_factor /= 2;
@@ -205,8 +201,7 @@ public:
 
     //-----------------------------------------------------------
     //Phase resync
-    // TODO Renable here, in initialization, or through separate set_phase_resync(bool enable) function
-    _regs.phase_resync = adf535x_regs_t::PHASE_RESYNC_DISABLED;
+    _regs.phase_resync = adf535x_regs_t::PHASE_RESYNC_ENABLED;
 
     _regs.phase_adjust = adf535x_regs_t::PHASE_ADJUST_DISABLED;
     _regs.sd_load_reset = adf535x_regs_t::SD_LOAD_RESET_ON_REG0_UPDATE;
@@ -427,13 +422,10 @@ inline double adf535x_impl<adf5356_regs_t>::_set_frequency(double target_freq, d
   const auto MOD2 = static_cast<uint16_t>(std::min(floor(_pfd_freq / gcd), static_cast<double>(ADF535X_MAX_MOD2)));
   const auto FRAC2 = static_cast<uint16_t>(std::min(round(residue * MOD2), static_cast<double>(ADF535X_MAX_FRAC2)));
 
-  const double coerced_vco_freq = _pfd_freq * (
-    double(INT) + (
-      (double(FRAC1) +
-      (double(FRAC2) / double(MOD2)))
-      / double(ADF535X_MOD1)
-    )
-  );
+  const double coerced_vco_freq = _pfd_freq *
+    (_fb_after_divider ? rf_divider : 1) *
+    (double(INT) + ((double(FRAC1) + (double(FRAC2) / double(MOD2)))
+    / double(ADF535X_MOD1)));
 
   const double coerced_out_freq = coerced_vco_freq / rf_divider;