code question about AN3748

carloAT — Thu, 22 Apr 2010 20:40:32 GMT

Hi!

In the main file there is this definition of a function pointer:

void (* const _UserEntry[])() @0x000011E4= // modificato @0x000011C0=
{
0x4E714EF9, //asm NOP(0x4E71), asm JMP(0x4EF9)
_startup,
};

What does the code inside do?

If i look at the memory with the debugger, I see that at address 0x000011C0 there is

4E 71 4E F9 00 00 12 EC

I have never seen this syntax before but I assume that 0x4E714EF9 copy this value in the memory. What's the point of saving this value in memory? There is a comment with a jump. Does it jump to this value?

Where 00 00 12 EC come from? Is it the address of _startup?

I would be happy if anyone could explain me what this code does.

Thanks!

Re: code question about AN3748

carloAT — Tue, 04 May 2010 20:09:22 GMT

up :smileyhappy:

topic code question about AN3748 in ColdFire/68K Microcontrollers and Processors

code question about AN3748

Re: code question about AN3748