Setups for Fallback ABM, Alternative Boot Mode

[User10969]

Hello,

due to the UM of XMC4500 following steps/setups must be done if the Fallback ABM is used:

1. Boot mode pin encoding for PORST (Table 26-1): BMI
2. Content of UCB2, User Configuration Block 2 evaluated by SSW after PORST/any reset: SWCON = Fallback ABM, Speed-up = 1, valid XOR checksum, all others optional
3. ABM[0] at end of 1st 64kB sector on flash: valid magic key, valid start address of code, app.-length = 0xffff ffff (if not used), app.-crc32 = 0xffff ffff (if not used), valid crc32 of ABM header
4. ABM[1] at end of 2nd 64kB sector on flash: valid magic key, valid start address of code, app.-length = 0xffff ffff (if not used), app.-crc32 = 0xffff ffff (if not used), valid crc32 of ABM header

If ABM[0] corrupted, SSW will choose the ABM[1].

Are the above described steps/setups correct ? Thanks in advance for any comment.

[Travis]

Hi,

You can reference to these code..

[Travis]

1. Boot mode pin encoding for PORST (Table 26-1): BMI

Yes, Startup Software (SSW) will check on this pin to determine BOOT MODE

2. Content of UCB2, User Configuration Block 2 evaluated by SSW after PORST/any reset: SWCON = Fallback ABM, Speed-up = 1, valid XOR checksum, all others optional
3. ABM[0] at end of 1st 64kB sector on flash: valid magic key, valid start address of code, app.-length = 0xffff ffff (if not used), app.-crc32 = 0xffff ffff (if not used), valid crc32 of ABM header
4. ABM[1] at end of 2nd 64kB sector on flash: valid magic key, valid start address of code, app.-length = 0xffff ffff (if not used), app.-crc32 = 0xffff ffff (if not used), valid crc32 of ABM header

Basically, if the checksum listed in the ABM is correct for both the ABM and defined software the MCU will executed the code from the specified boot address.