MCB2100 and assembly program

No, assembly is not required to understand the "internal concepts" of a processor.

Assembly language may be required to write the glue logic before you enter a C function, since the C compiler may not have special keywords to generate the correct prologue/epilogue for the exception handlers.

You could even write most of the initialization code directly in C, if you could live with the incompatibilities that such a init function would enter without zero-initialized and initialized variables and with large parts of the RTL forbidden to call. However, such a concept would kill the compiler vendor with support calls - people who would assume that anything was allowed before the initialization was done and the environment fully C-compliant...

No, assembly is not required to understand the "internal concepts" of a processor.

Assembly language may be required to write the glue logic before you enter a C function, since the C compiler may not have special keywords to generate the correct prologue/epilogue for the exception handlers.

You could even write most of the initialization code directly in C, if you could live with the incompatibilities that such a init function would enter without zero-initialized and initialized variables and with large parts of the RTL forbidden to call. However, such a concept would kill the compiler vendor with support calls - people who would assume that anything was allowed before the initialization was done and the environment fully C-compliant...