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29 lines
409 B
NASM
29 lines
409 B
NASM
.INCLUDE "tn13def.inc"
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; data direction = output
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sbi DDRB, 1 ; PB1
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loop:
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; clear bit
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cbi PORTB, 1
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; wait
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; takes roughly ((2+2)*(256*256))/(9.6*1000*1000/8) ~ .218 seconds.
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; 2 cycles SBIW + 2 cycles BRNE for 256*256 subtractions
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; 9.6 MHz (CKSEL[1..0] = 10) with CKDIV=8
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loop1:
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sbiw ZL, 1
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brne loop1
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; set bit
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sbi PORTB, 1
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; wait
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loop2:
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sbiw ZL, 1
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brne loop2
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; again! again! again!
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rjmp loop
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