I have some Si5338 devices where the register values are not 0xFF. Does this mean they have been programmed?
No, all registers are not necessarily 0xFF for blank devices. The registers you read are stored in hardware registers (i.e. like RAM). The NVM gets downloaded into the registers at power up, but some registers are set to specific values by default, even in blank devices.
What would the registers read of an unprogrammed part? I have a tray of parts we purchased, and none of the registers read 0xFF. Most have 0x00, some have other values. I have three that have the same values, while a fourth have other values.
I am using the register programmer. It does not seem to have a blank check. I load my .nvm. If I do a write and verify, it says ok and I see my desired values. But when I reset the programmer or change the chip out, read another, change back, the orignal values are there.
I suspect that the tray of devices has been previously programmed, and I am only writing the RAM. I may be doing something wrong, but I don't see anything else that would write the values.