47 lines
463 B
NASM
47 lines
463 B
NASM
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; This simple example reads data from external device through P2
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; and outputs it inverted through P1.
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include 'hex.inc'
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include '8051.inc'
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ORG 0
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JMP setup
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ORG 3
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JMP ext0_interrupt
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ORG 0Bh
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JMP timer0_interrupt
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ORG 30h
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setup:
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SETB EX0
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SETB IT0
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CLR P0.7
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MOV TH0,#-40
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MOV TL0,#-40
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MOV TMOD,#2
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SETB TR0
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SETB ET0
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SETB EA
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JMP $
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timer0_interrupt:
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CLR P3.6
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SETB P3.6
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RETI
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ext0_interrupt:
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CLR P3.7
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MOV A,P2
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CPL A
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MOV P1,A
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SETB P3.7
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RETI
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