Question
I am interfacing two AD9739 DAC's with VIRTEX-5. In the datasheet of AD9739 at
PAGE NO. 49 under the section of INTERRUPT REQUESTS, it is given that --"If the
pin is used to determine that an interrupt has occurred, it is also necessary
to check Register 0x04 to determine which bit caused the interrupt because the
pin can only indicate that an interrupt has occurred. To clear an IRQ, it is
necessary to write a 1 to the bit in Register 0x04 that caused the interrupt."
but 0x04 is a READ ONLY register ! !
What should we we do after we read 0x04 to clear the IRQ. Lets say we read in
0x04 that MU CONTROLLER has been UN-LOCKED, then what should we do ? like
should we continue sending digital data ?? OR
Send GARBAGE data meanwhile MU detector LOCKS itself ?? OR
RESET the DAC ??
OR RESET 0x03 ??
Answer
Please see the below diagram which is Figure 110 in datasheet:(Attached file)
To clear an IRQ, it’s necessary to write a 1 to the bit in Register 0x04 that
caused the interrupt. Yes, they are read-only register, but in terms of
figure110, writing 1 will reset the INT.