Hi Bernie,
To select the correct start up mode, user need to configure the BMI.PINDIS and pin HWCFG[3], additional BMI.HWCFG[6:4] or HWCFG[5:4] pins.
BMI.HWCFG[6:4] is loaded from a valid BMHD. BMHD is located at the fixed address inside PFLASH. There are 4 BMHDs inside AURIX. User need to configure and program the BMHDs. (BMHD0: A000 0000H, BMHD1: A002 0000H, BMHD2: A000 FFE0H, BMHD3: A001 FFE0H).
HWCFG[5:4] pins are only evaluated if a valid BMHD found by SSW with BMI.PINDIS = 0 and pin HWCFG[3] = 0 (Boot from Pins HWCFG[5:4]).
After reset, AURIX SSW (Startup SW, internal firmware) will evaluate the BMI (Boot Mode Index) inside BMHDs (Boot Mode Header) to select the correct start up mode. If no valid BMHD found the Start-up Mode Generic Bootstrap Loader is used (independent of pin HWCFG3).
Best regards,
Mr. AURIX™
