diff options
| -rw-r--r-- | host/lib/usrp/common/ad9361_driver/ad9361_device.cpp | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp b/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp index 9275c83f5..5574022b6 100644 --- a/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp +++ b/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp @@ -1817,6 +1817,10 @@ void ad9361_device_t::initialize() /* Set TXers & RXers on (only works in FDD mode) */ _io_iface->poke8(0x014, 0x21); + + /* We won't be using immediate-Tx-attenuation, so we de-assert "Mask Clr + * Atten Update". */ + _io_iface->poke8(0x077, 0x00); } void ad9361_device_t::set_io_iface(ad9361_io::sptr io_iface) @@ -2203,11 +2207,6 @@ double ad9361_device_t::set_gain(direction_t direction, chain_t chain, const dou return gain_index; } else { - /* Setting the below bits causes a change in the TX attenuation word - * to immediately take effect. */ - _io_iface->poke8(0x077, 0x40); - _io_iface->poke8(0x07c, 0x40); - /* Each gain step is -0.25dB. Calculate the attenuation necessary * for the requested gain, convert it into gain steps, then write * the attenuation word. Max gain (so zero attenuation) is 89.75. @@ -2215,8 +2214,8 @@ double ad9361_device_t::set_gain(direction_t direction, chain_t chain, const dou * "value" is out of bounds, so range checking must be performed * outside this function. */ - double atten = AD9361_MAX_GAIN - value; - uint32_t attenreg = uint32_t(atten * 4); + const double atten = AD9361_MAX_GAIN - value; + const uint32_t attenreg = uint32_t(atten * 4); if (chain == CHAIN_1) { _tx1_gain = value; _io_iface->poke8(0x073, attenreg & 0xFF); @@ -2226,6 +2225,13 @@ double ad9361_device_t::set_gain(direction_t direction, chain_t chain, const dou _io_iface->poke8(0x075, attenreg & 0xFF); _io_iface->poke8(0x076, (attenreg >> 8) & 0x01); } + + /* After we've set both registers for the new gain, we apply it (assert + * "Immediately Update TPC Atten"). This avoids the attenuation from + * intermediately becoming very small (i.e., high output power) during + * the set-gain cycle. + */ + _io_iface->poke8(0x07c, 0x40); return AD9361_MAX_GAIN - ((double)(attenreg) / 4); } } |