I have a couple of questions regarding programming the PF0100 with the KITPFPGMEVME Programmer.
1. I'd like to incorporate PF0100 programming capability into my evaluation board. As per Document Number: KTPFPGHWUG, Page 6 (Rev B Programmer guide):
"When connecting the KITPFPGMEVME programmer to an application board with an i.MX processor and a PF
device sharing the I2C bus, it is required to disconnect the processor I2C lines from the communication bus.
Since programming the OTP fuse on the PF Device is a one-time event during production, the most simple and
cost-effective solution for isolating the processor I2C lines is to add two 0 Ω resistors (R5 and R6), which should
not be placed during OTP programming, but are soldered down for normal operation."
Is it required to disconnect the on-board processor I2C bus for programming? I am using a Zynq Z7020 rather than an I.MX. This would add an extra step in production (loading the 2 0R resistors), rather than the nice clean approach of programming the PMIC in the PCB-A test jig stage, right before the rest of the board is tested. What is the risk here? I plan to program the PMIC with the rest of the board powered down, using the programmer 3V3 rail to only power up the PMIC, so the on-board processor will be off. The I2C data will be addressed specifically to the PMIC, so I'm not sure what the issue would be here?
2. On the same page of the document, the schematic diagram has the external V3.3 routed to System VIN. Is there a requirement for this? It looks to me that as long as V3.3 is going to Vin of the PMIC, this is not required for PMIC programming. Is this correct?
3. One finally Q - at what point during the programming process do the regulators actually start regulating at their correct new output voltage? Is there any precautions that should be taken here to protect other circuit subsystems?