Re: What is a vector file?

[Michael Schwingen <rincewind at discworld dot dascon dot de>]

On Sun, Oct 22, 2000 at 09:29:43AM -0700, Home Email wrote:
> It looks as though as soon as the microcontroller
> begins it is initalizing itself.  Is this what the
> vector file is for?

It contains various exception vectors, which are located at the beginning of
the ROM for the SH.

Look up the chapter on exception handling in the SH manual - you will then
get an impression why these vectors are needed. After that, this method of
creating them will become more clear.

> Do all embedded microcontrollers use a file like this
> at the beginning of their their boot prom and how much

No. It depends on the CPU where exception vectors are placed - the 68k
family has only the reset vector/stack fixed at address 0 and 4, the rest
may be relocated. Other CPUs use fixed locations at the end of memory.

Only the reset vector is needed at a fixed location - the rest depends on
the memory map of your hardware - for a system where the exception vectors
are placed in RAM, you will have to initialize them by some other way in
your startup code.

cu
Michael

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