Doughman shows how an assembly language programmer can use the stack for storing local or temporary variables and for subroutine parameter passing. Using the stack for these purposes reduces the amount of RAM needed and makes a routine both reentrant and recursive. The claimed benefit is that the resulting programs will be easier to maintain and debug.

Although this application note is specific to the M68HC11 microprocessor, the first part of the note describes general principles that should benefit any assembly language programmer. The second part is specific to the syntax and macros of the M68HC11. Both parts are clearly written at an introductory level. The figures and examples help to clarify the material.