Datasheet

AD9734/AD9735/AD9736
Rev. A | Page 31 of 72
FULL SCALE CURRENT (FSC) REGISTERS (REG. 2, REG. 3)
ADDR Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x02 FSC_1 SLEEP – – – – – FSC<9> FSC<8>
0x03 FSC_2 FSC<7> FSC<6> FSC<5> FSC<4> FSC<3> FSC<2> FSC<1> FSC<0>
Table 12. Full Scale Current Output Register Bit Descriptions
Bit Name Read/Write Description
SLEEP WRITE
0, enable DAC output.
1, set DAC output current to 0 mA.
FSC<9:0> WRITE 0x000, 10 mA full-scale output current.
0x200, 20 mA full-scale output current.
0x3FF, 30 mA full-scale output current.
LVDS CONTROLLER (LVDS_CNT) REGISTERS (REG. 4, REG. 5, REG. 6)
ADDR Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x04 LVDS_CNT1 MSD<3> MSD<2> MSD<1> MSD<0> MHD<3> MHD<2> MHD<1> MHD<0>
0x05 LVDS_CNT2 SD<3> SD<2> SD<1> SD<0> LCHANGE ERR_HI ERR_LO CHECK
0x06 LVDS_CNT3 LSURV LAUTO LFLT<3> LFLT<2> LFLT<1> LFLT<0> LTRH<1> LTRH<0>
Table 13. LVDS Controller Register Bit Descriptions
Bit Name Read/Write Description
MSD<3:0> WRITE
0x0, set setup delay for the measurement system.
READ
If ( LAUTO = 1), the latest measured value for the setup delay.
If ( LAUTO = 0), readback of the last SPI write to this bit.
MHD<3:0> WRITE
0x0, set hold delay for the measurement system.
READ
If ( LAUTO = 1), the latest measured value for the hold delay.
If ( LAUTO = 0), readback of the last SPI write to this bit.
SD<3:0> WRITE
0x0, set sample delay.
READ
If ( LAUTO = 1), the result of a measurement cycle is stored in this register.
If ( LAUTO = 0), readback of the last SPI write to this bit.
LCHANGE READ
0, no change from previous measurement.
1, change in value from the previous measurement.
NOTE: The average filter and the threshold detection are not applied to this bit.
ERR_HI READ One of the 15 LVDS inputs is above the input voltage limits of the IEEE reduced link specification.
ERR_LO READ One of the 15 LVDS inputs is below the input voltage limits of the IEEE reduced link specification.
CHECK READ
0, phase measurement—sampling in the previous or following DATA cycle.
1, phase measurement—sampling in the correct DATA cycle.
LSURV WRITE
0, the controller stops after completion of the current measurement cycle.
1, continuous measurements are taken and an interrupt is issued if the clock alignment drifts beyond the
threshold value.
LAUTO WRITE
0, sample delay is not automatically updated.
1, continuously starts measurement cycles and updates the sample delay according to the measurement.
NOTE: LSURV (Reg. 6, Bit 7) must be set to 1 and the LVDS IRQ (Reg. 1, Bit 3) must be set to 0 for AUTO mode.
LFLT<3:0> WRITE
0x0, average filter length, Delay = Delay + Delta Delay/2^ LFLT <3:0>, values greater than 12 (0x0C) are
clipped to 12.
LTRH<2:0> WRITE
000, set auto update threshold values.