diff options
Diffstat (limited to 'host/lib')
| -rw-r--r-- | host/lib/types/serial.cpp | 3 | ||||
| -rw-r--r-- | host/lib/usrp/cores/spi_core_3000.cpp | 26 |
2 files changed, 22 insertions, 7 deletions
diff --git a/host/lib/types/serial.cpp b/host/lib/types/serial.cpp index 9b8336dd8..52961691c 100644 --- a/host/lib/types/serial.cpp +++ b/host/lib/types/serial.cpp @@ -40,7 +40,8 @@ spi_config_t::spi_config_t(edge_t edge): mosi_edge(edge), miso_edge(edge) { - /* NOP */ + // By default don't use a custom clock speed for the transaction + use_custom_divider = false; } void i2c_iface::write_eeprom( diff --git a/host/lib/usrp/cores/spi_core_3000.cpp b/host/lib/usrp/cores/spi_core_3000.cpp index 0656d910a..d33624b0d 100644 --- a/host/lib/usrp/cores/spi_core_3000.cpp +++ b/host/lib/usrp/cores/spi_core_3000.cpp @@ -34,7 +34,7 @@ class spi_core_3000_impl : public spi_core_3000 { public: spi_core_3000_impl(wb_iface::sptr iface, const size_t base, const size_t readback): - _iface(iface), _base(base), _readback(readback), _ctrl_word_cache(0) + _iface(iface), _base(base), _readback(readback), _ctrl_word_cache(0), _divider_cache(0) { this->set_divider(30); } @@ -46,7 +46,21 @@ public: size_t num_bits, bool readback ){ - boost::mutex::scoped_lock lock(_mutex); + boost::lock_guard<boost::mutex> lock(_mutex); + + //load SPI divider + size_t spi_divider = _div; + if (config.use_custom_divider) { + //The resulting SPI frequency will be f_system/(2*(divider+1)) + //This math ensures the frequency will be equal to or less than the target + spi_divider = (config.divider-1)/2; + } + + //conditionally send SPI divider + if (spi_divider != _divider_cache) { + _iface->poke32(SPI_DIV, spi_divider); + _divider_cache = spi_divider; + } //load control word boost::uint32_t ctrl_word = 0; @@ -55,17 +69,16 @@ public: if (config.mosi_edge == spi_config_t::EDGE_FALL) ctrl_word |= (1 << 31); if (config.miso_edge == spi_config_t::EDGE_RISE) ctrl_word |= (1 << 30); - //load data word (must be in upper bits) - const boost::uint32_t data_out = data << (32 - num_bits); - //conditionally send control word if (_ctrl_word_cache != ctrl_word) { - _iface->poke32(SPI_DIV, _div); _iface->poke32(SPI_CTRL, ctrl_word); _ctrl_word_cache = ctrl_word; } + //load data word (must be in upper bits) + const boost::uint32_t data_out = data << (32 - num_bits); + //send data word _iface->poke32(SPI_DATA, data_out); @@ -91,6 +104,7 @@ private: boost::uint32_t _ctrl_word_cache; boost::mutex _mutex; size_t _div; + size_t _divider_cache; }; spi_core_3000::sptr spi_core_3000::make(wb_iface::sptr iface, const size_t base, const size_t readback) |