Pflag program status register shows below:

From the table, you can see, NT0, NPD (show double mode), can be read and write, C, DC, Z (shows the bit state) can be both read and write; but LVD36，LVD24(low voltage detection bit) can only read and can not write.
In Sonix chip datasheet, all Read/Write line shows R/W's are all read and write bit, user can make read and write operation of it. if there is only R or W, the bit of that register only can only read or write.