CC78K0S Datasheet, PDF (485/520 Pages) NEC – C Compiler Ver.1.30 or Later Language

CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER
This chapter introduces how to effectively use this C compiler.
13.1 Efficient Coding
When developing 78K/0S Series application products, efficient object generation may be realized with this C
compiler by utilizing the saddr area or callt area of the device.
• Use external variables
if (saddr area is usable)
sreg/_ _sreg variables are used/
compiler option (-RD) is used
• Use 1-bit data
if (saddr area is usable)
bit/boolean/ _ _boolean type variables are used
• Function definition
if (function to be called several times)
if (callt area is usable)
Use as _ _callt/callt function (effective for reducing code size)
if (not used recursively)
Use as _ _leaf/norec function
if (automatic variables are not used)
Use as noauto function
if (automatic variables are used &&saddr area is usable)
register declaration
User’s Manual U14872EJ1V0UM
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