Arithmetic Accelerator

The Cx51 Compiler uses the 32-bit and 16-bit arithmetic operations of the DS80C390, DS80C400 and DS5240 to improve performance of a number of math-intensive operations. C language programs execute considerably faster when using either of these MCUs.

Use the following suggestions to help guarantee that only one thread of execution uses the arithmetic processor:

• Use the MODDA directive to compile functions which are guaranteed to execute only in the main program or functions used by one interrupt service routine, but not both.
• Compile all remaining functions with the NOMODDA directive.