35 lines
752 B
ArmAsm
35 lines
752 B
ArmAsm
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.equ ADDR_BASE, 0xBF88
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.equ TRISD, 0x60C0
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.equ PORTD, 0x60D0
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.equ TRISE, 0x6100
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.equ LATE, 0x6120
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.data
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.text
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.globl main
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main:
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lui $t7, ADDR_BASE
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lw $t0, TRISD($t7)
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ori $t0, $t0, 0x0100 # 0000 0001 0000 0000 (isola bit 8)
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sw $t0, TRISD($t7) # Configurar RD8 como input
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lw $t0, TRISE($t7)
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andi $t0, $t0, 0xFFFE # 1111 1111 1111 1110 (isola bit 0)
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sw $t0, TRISE($t7) # Configurar RE0 como output
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loop:
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lw $t0, PORTD($t7)
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andi $t0, $t0, 0x0100 # 0000 0001 0000 0000 (isola bit 8)
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srl $t0, $t0, 8 # Necessário colocar o bit lido na posição do bit 0
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xori $t0, $t0, 0xFFFF # Negar RD8
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lw $t1, LATE($t7)
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andi $t1, $t1, 0xFFFE # 1111 1111 1111 1110 (isola bit 0)
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or $t1, $t1, $t0
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sw $t1, LATE($t7)
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j loop
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jr $ra
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