Page 156 -
P. 156
MOVC A,@A+DPTR
CJNE A,#FFH,$1
SETB C
RET
$1:
MOV TONE1,A
INC DPTR
CLR A
MOVC A,@A+DPTR
MOV TONE2,A
INC DPTR
CLR C
RET
ON_OFF_SPEAK:
PUSH A
PUSH DPL
PUSH DPH
MOV DPTR,#PC_8255
MOVX A,@DPTR
XRL A,#10H
MOVX @DPTR,A
MOV TH1,TONE1
MOV TL1,TONE2
POP DPH
POP DPL
POP A
RETI
DELAY_0.5S:
MOV R7,#05
$3:
MOV R6,#200
$2:
MOV R5,#248
NOP
$1:
DJNZ R5,$1
DJNZ R6,$2
DJNZ R7,$3
RET