Hello
 
Just to close the loop here, the HC08 or HC12 assembler manual include a section around mixing C and assembly in an application.
 
  - Depending on the CPU you are using open the file {Install}\Help\PDF\Assembler_HC08.pdf or
    {Install}\Help\PDF\Assembler_HC12.pdf.
  - For HC08 go to chapter "Using the HC(S)08 Assembler", section
     "Mixed C and Assembler application"
  - For HC12 go to chapter "Using the HC(S)12 Assembler", section
     "Mixed C and Assembler application".
 
 
CrasyCat