CC78K4 Datasheet, PDF (29/523 Pages) NEC – CC78K4 Ver.2.30 or Later, C Compiler Language

CHAPTER 1 GENERAL
<3> Using the saddr area
Variables declared with the keyword sreg can be allocated to the saddr area. Instructions to these sreg
variables are shorter in code length than those to memory. This helps shorten object code and also
improves program execution speed. Variables can be allocated to the saddr area also by option (only to the
saddr2 area).
<4> sfr area
By declaring use of sfr names, manipulations on the sfr area can be described at the C source file.
<5> noauto functions
Functions declared as noauto do not output code for preprocessing and postprocessing (stack frame
formation). By calling a noauto function, arguments are passed via registers. This helps shorten object
code and improve program execution speed as well. This function has restrictions on arguments/automatic
variables. For the details, refer to 11.5 (5) noauto function.
<6> norec/_ _leaf functions
Functions declared as norec/_ _leaf do not output code for preprocessing and postprocessing (stack frame
formation). By calling a norec/_ _leaf function, arguments are passed via registers as much as possible.
Automatic variables to be used inside a norec/_ _leaf function are allocated to register or the saddr area.
This helps shorten object code and also improve program execution speed. This function has restrictions on
arguments/automatic variables and is not allowed to call a function. For the details, refer to 11.5 (6) norec
function.
<7> bit type variables and boolean/_ _boolean type variables
Variables with a 1-bit storage area are generated. By using the bit type variable or boolean/_ _ boolean
type variable, the saddr2 area can be accessed in bit units.
The boolean/_ _boolean type variable is the same as the bit type variable in terms of both function and
usage.
<8> boolean1 type variables
Variables with a 1-bit storage area are generated. By using the _ _ boolean1 type variable, the saddr1 area
can be accessed in bit units.
The _ _boolean1 type variable is the same as the bit type variable in terms of both function and usage.
<9> ASM statements
The assembler source program described by the user can be embedded in an assembler source file to be
output by this C compiler.
<10> Interrupt functions
A vector table and an object code corresponding to the interrupt are output. This allows programming of
interrupt functions at the C source level.
<11> Interrupt function qualifier
This qualifier allows the setting of a vector table and interrupt function definitions to be described in a
separate file.
User’s Manual U15556EJ1V0UM
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