Sundance SMT381 2004 - Manual (Page 48)

For a detailed description of the configurable bits in the Clock Synthesizer register
please refer to the “Clock Synthesizer” section under “Firmware Building Blocks” at
the end of this document.
5.4.7 PLL Setup Registers (Write Add 0x802 – 0x809)
These registers set up the frequency of the PLL circuit on the SMT381. There are
two sets of registers – one set for setting up the IF side of the PLL, and the other set
for setting up the RF side of the PLL. The IF side is unconnected, while the RF side
is connected to a 600 – 1200 MHz VCO circuit which is divided by two before
entering the DAC at a frequency of 300 – 600MHz. All registers must be initialized,
and only when writing to the final register will both the IF and RF side be configured
to their new values.
31 .. 28 27 .. 24 23 .. 20 19 .. 16 15 .. 12 11 .. 8 7 .. 4 3 .. 0
Command Address Data MSB Data LSB
0x1
0x1
0x1
0x1
0x1
0x1
0x1
0x1
0x802
0x803
0x804
0x805
0x806
0x807
0x808
0x809
Not Used
Not Used
Not Used
Not Used
Smt381Pll_RfR_Reg1
Smt381Pll_RfR_Reg2
Smt381Pll_RfN_Reg1
Smt381Pll_RfN_Reg2
Not Used
Not Used
Not Used
Not Used
Smt381Pll_RfR_Reg1
Smt381Pll_RfR_Reg2
Smt381Pll_RfN_Reg1
Smt381Pll_RfN_Reg2
Figure 33. PLL Setup Registers (Write Only).
For a detailed description of the configurable bits in the PLL registers please refer to
the “PLL Configuration” section under “Firmware Building Blocks” at the end of this
document.
5.4.8 DAC Setup Registers (Write Add 0x900 – 0x905)
These registers configure the internal functionality of the DAC on the SMT381. There
are six registers – 4 data registers an address register and setup register. The
address and setup registers must be set up before the data registers. Once the data
registers are written to the data, address and setup information contained in all the
registers will be transferred to the DAC over a serial interface.
31 .. 28 27 .. 24 23 .. 20 19 .. 16 15 .. 12 11 .. 8 7 .. 4 3 .. 0
Command Address Data MSB Data LSB
0x1 0x900 Smt381SetupData Smt381SetupData
0x1 0x901 Smt381DacAddress Smt381DacAddress
0x1 0x902 Smt381DacData(LSB) Smt381DacData(LSB)
0x1 0x903 Smt381DacData Smt381DacData
0x1 0x904 Smt381DacData Smt381DacData
0x1 0x905 Smt381DacData(MSB) Smt381DacData(MSB)
Figure 34. DAC Setup Registers (Write Only).