[O] emphasis inside source block?

[David Rogoff]

Sorry if this has been discussed but I wasn’t able to find info on it.
I have lots of source blocks in my org files (tcl, verilog, shell-script, etc). 
 I want to be able to highlight (e.g. *bold*) text in the code but this doesn’t 
work since it’s using the specified language mode instead of org mode.  Is 
there some way to use a minor mode within source blocks that would allow this?  
It’s become a big problem in generating documentation.

Thanks,

 David