For the LS1046A, when PORESET_B is asserted, are all QSPI signals in high impedance state?
I am wondering if I can program QSPI RCW/PBI/boot flash using an external master if I apply power and keep PORESET_B asserted. Any problems doing it this way?
Yes, external master can program SPI Flash connected to QSPI when PORESET_B is asserted.