I am facing a problem regarding writing a value to a certain register in AD7293 evaluation board.
In the configuration page (0x02), for the address 0x23 which is the register regarding background monitoring of some certain values, as much as try I cannnot enable background conversions for RSx+mon values which are bits D8-D11.
I write 1 to the corresponding bits (1111) but when I re-read this very register only the bit associated to RS3+mon is enables and the rest get disable again! (1111 turn to 1000).
and I tried by different combination of values intending to enable some RSx+ pin and each time also the reserved value (bit D12-D15) changes from 0 to different values, and again bits related to RSx+ turn to 0.
I also tried to figure out if it is a protection mechanism and some other registers need to be configured before enabling the RSx+, but throughout datasheet I couldn't find anything.
I would appreciate if someone can help me.
Thanks in advance.
Unfortunately the readback from this register is slightly different than other registers.
While writing to this register the data format is as follows.
D15 – D12
D11 – D8
D7 – D4
D3 – D0
RS3+MON – RS0+MON
BI-VOUT3mon – BI-VOUT0mon
VDD3 – VDD0
However when reading from this register, the data format is:
D14 – D11
D10 – D8
The data (i.e. the RSx+MON background enable status) in the upper byte is shifted.
and just to be sure, is there any other register in this device bahaving the same way?
No, this is the only register that has this behaviour.
I appreciate the help.