Calling assembli function from TCONF files

Hi,

I need to set the fxn parameter of a HWI instance as a function written in assembly (in a s64P file)

I have already set a the fxn of a HWI instance to a C function whthout any issues:

prog.module("HWI").instance("HWI_INT5").fxn = prog.extern("ISR_fxn");

But when I try to assign the fxn as an assembly function  I get a compilation error:

 prog.module("HWI").instance("HWI_INT4").fxn = prog.extern("asm_isr", "asm");

The error I get is something like:

undefined

 symbol

---------

asm_isr

Do you know if I am missing something?

Regards,

Armando