Got a max32664A on a Sparkfun board thats already programmed with version 10.1.0 firmware and can easily wiggle the power, reset and mfio pins to go into app mode (and correctly read the app version) or boot mode (and read booter version 3.0.0 and page size of 8192) as per the datasheet.
Got a new max32664A chip on my own board with the default firmware 1.9.1 which power/reset/mfio puts into app mode (and correctly reads the app version) but it refuses to go into boot mode.
The chip appears to answer back to the I2C write and reads but sends back zero values- can see this on a scope. Also the max32664 drives (or pulls up) the mfio pin to 1.8V after approx 2.5 ms after reset is taken high.
As this is an old firmware version, is there some difference in the method to enter boot mode. I cannot find any older datasheets or user guides that may clarify this issue.