Callf – NEC 78K/0 Series User Manual
Page 95
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
95
User's Manual U12326EJ4V0UM
Call Flag
CALLF
Subroutine Call (11 Bit Direct Specification)
[Instruction format]
CALLF Target
[Operation]
(SP–1)
← (PC+2)
H
,
(SP–2)
← (PC+2)
L
,
SP
← SP–2,
PC
← target
[Operand]
Mnemonic
Operand(target)
CALLF
!addr11
[Flag]
Z
AC
CY
[Description]
•
This is a subroutine call which can only be branched to addresses 0800H to 0FFFH.
•
The start address (PC+2) of the next instruction is saved in the stack and is branched in the range of
addresses 0800H to 0FFFH.
•
Only the lower 11 bits of an address are specified (with the higher 5 bits fixed to 00001B).
•
The program size can be compressed by locating the subroutine at 0800H to 0FFFH and using this
instruction. If the program is in the external memory, the execution time can be decreased.
[Description example]
CALLF !0C2AH; Subroutine call to 0C2AH