SPRZ408D June 2014 – June 2021 AM4372 , AM4376 , AM4377 , AM4378 , AM4379
ROM: Non-muxed Fast NOR boot does not configure A26 and A27
1.1, 1.2
Boot mode affected: NOR Low Latency (FAST_NOR)
In the non-muxed NOR Low Latency Boot Mode, the ROM uses pinmux option 0 to configure the pin mux configuration, however A26 and A27 are not configured to pinmux mode 4, and thus are not driven during boot.
Use non-muxed NOR boot, which correctly configures A26 and A27. Or, if FAST_NOR boot must be used, external pull-down resistors must be included on GPMC_A26 and GPMC_A27 signals if these signals are connected to the NOR flash. Appropriate resistor values must be determined to ensure these signals are held in a valid low state during boot.