Why is the Boot Select setting in the Config0/1 not valid in Keil ICE Debug mode?

[a_ziliu]

In the ICE Debug mode, the code will be programmed in the area selected by the Flash Select field (APROM or LDROM) and boot from this area instead of booting from the area set by Boot Select in the Config0/1.
Therefore, regardless of the Boot Select setting in the Config0/1, in Debug mode, the code will be programmed in the area selected by Flash Select and the chip will boot from this area.