I have several questions about configuring the LMX2820 via SPI:
- During the initial power on programming sequence, do all registers need to be programmed or only those whose programmed value differs from the default? (i.e., reset value).
- For reprogramming, the datasheet makes it sound like apart from register 0 (which is used to trigger calibration), only the registers whose value has changed need to be programmed and they can be programmed in any order. e.g., i could program R38 then r41 then r0. is this correct?
- During the initial power up sequence do I actually need to program the registers in descending order, or is it simply that register 0 needs to be programmed last?
- What triggers the LDO power up sequence? Do the LDOs automatically start powering up after CE is brought high? Or, does the power up sequence result from programming a register (e.g., programming register 0 with POWERDOWN=0)? Something else?