Datasheet

AD5570
Rev. C | Page 18 of 24
Readback
The AD5570 allows the data contained in the DAC register to
be read back, if required. As with daisy chaining, an external
pull-up resistor of ~5 kΩ on SDO is required. The data in the
DAC register is available on SDO on the falling edges of SCLK
when
SYNC
is low. On the 16
th
SCLK edge, SDO is updated to
repeat SDIN with a delay of 16 clock cycles.
To read back the contents of the DAC register without writing
to the part, take
SYNC
low while
LDAC
is held high.
Daisy-chaining readback is also possible through the SDO pin
of the last device in the DAC chain because the DAC data passes
through the DAC chain with the appropriate latency.
68HC11*
MISO
SYNC
SDIN
SCLK
MOSI
SCK
PC7
PC6
LDAC
SDO
SYNC
SCLK
LDAC
SDO
SYNC
SCLK
LDAC
SDO
SDIN
SDIN
*ADDITIONAL PINS OMITTED FOR CLARITY.
AD5570*
AD5570*
AD5570*
V
LOGIC
R
R
R
03760-013
Figure 38. Daisy-Chaining Using the AD5570