NEC 78K0 Series User Manual page 96

CHAPTER 4 MEMORY BANK SELECT FUNCTION (
• Software example
RAMD DSEG SADDR
R_BNKA: DS 2
R_BNKN: DS 1
R_BNKRN: DS 1
MOV R_BNKN,#BANKNUM TEST
MOVW R_BNKA,#TEST
CALL !BNKCAL
:
:
BNKC CSEG AT
BNKCAL:
MOV A,R_BNKN
XCH A,BANK
MOV R_BNKRN,A
CALL !BNKCALS
XCH A,R_BNKRN
MOV BANK,A
RET
BNKCALS:
MOVW AX,R_BNKA
BR AX
BN3 CSEG BANK3
TEST:
MOV ⋅⋅⋅
:
:
RET
END
Remark In the software example above, the AX register is destructed. Multiplexed processing is not supported.
96
; Secures RAM for specifying an address at the calling destination.
; Secures RAM for specifying a memory bank number at the calling destination.
; Secures RAM for saving a memory bank number at the calling source.
; Store the memory bank number at the calling destination in RAM.
; Stores the address at the calling destination in RAM.
; Branches to an inter-memory bank calling processing routine.
7000H
; Inter-memory bank calling processing routine
; Acquires the memory bank number at the calling destination.
; Changes the bank and acquires the memory bank number at the calling source.
; Saves the memory bank number at the calling source to RAM.
; Calls a subroutine to branch to the calling destination.
;
; Specifies the memory bank number at the calling source.
; Returns to the calling source.
; Specifies the address at the calling destination.
; Branches to the calling destination.
;
Preliminary User's Manual U17260EJ3V1UD
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PD78F0536, 78F0537, AND 78F0537D ONLY)