CC78K4 Datasheet, PDF (478/523 Pages) NEC – CC78K4 Ver.2.30 or Later, C Compiler Language

CHAPTER 12 REFERENCING THE ASSEMBLER
<6> Restoring the saved registers
The saved contents of the base pointer and work registers are restored.
<7> Returning control to main
Figure 12-2. Stack Area After Return
Low address
Stack pointer
High address
Return address to main
l (Lower word)
l (Upper word)
Stack area
Return value
BC register
Word
or
RP2 register
BC register
Higher word
Lower word
The procedure for calling an assembly language from C and the processing of the assembly language routine
are illustrated in Figure 12-3.
[Function main]
Figure 12-3. Calling Assembly Language Routine from C
Low address
Stack pointer
Return address to main
l (Lower word)
l (Higher word)
Arguments to be passed to FUNC
AX register
i
High address
Stack area
[FUNC function]
Saving register
(U)UP, RP3, (V)VP*
Low address
Stack pointer
High address
Return address to main
l (Lower word)
l (Higher word)
Stack area
Processing
Storing return value
in BC or RP2, bc
Restoring registers
Return value
BC register
Word
or
RP2 register
Higher word
BC register
Lower word
478
User’s Manual U15556EJ1V0UM