Migrating from 8- to 16-bit processors

During the mid 1990´s, there has been a major upswing in the growth of applications requiring 16-bit microcontrollers. Dataquest have estimated that the growth of 16-bit devices will be more than double that of the combined growth of all categories of microcontrollers, at 43.9%. The main reasons for the growth in 16-bit applications is that pricing is becoming very competitive and traditional 8-bit applications typically require more processing power examples of these applications range from disk drive controllers, to airbags, to cellular communications. The trend for MCU users in embedded control systems is to migrate from assembly language to higher level languages such as C. The enhancement of instruction sets and addressing modes does not only make life easier for the assembly language programmer. When C code is compiled, the availability of lower-level resources such as efficient register use and data manipulation capabilities greatly increase the efficiency of the compiled C code. This is true for both code size generated and execution speed. Many of the enhancements of the M68HC12 have been a direct result of the recognition that M68HCll users need more performance and the option to migrate to a high level language without the penalties in code efficiency normally associated with such a step