main.asm
1 | cpu atmega8
| 2 | include /home/nutzer/eigene/prj/avr/asl/appnotes/tn13Adef.asm
| 3 | include /home/nutzer/eigene/prj/avr/inc/hilo.asm
| 4 |
| 5 | segment data
| 6 | org sram_start
| 7 | ctr_byte:
| 8 | res 1
| 9 | segment code
| 10 |
| 11 | rjmp isr_reset
| 12 | rjmp isr_ext_int0
| 13 | rjmp isr_pcint0
| 14 | rjmp isr_tim0_ovf
| 15 | rjmp isr_ee_rdy
| 16 | rjmp isr_ana_comp
| 17 | rjmp isr_tim0_compa
| 18 | rjmp isr_tim0_compb
| 19 | rjmp isr_watchdog
| 20 | rjmp isr_adc
| 21 |
| 22 | isr_ext_int0:
| 23 | isr_pcint0:
| 24 | isr_tim0_ovf:
| 25 | isr_ee_rdy:
| 26 | isr_ana_comp:
| 27 | isr_tim0_compa:
| 28 | isr_tim0_compb
| 29 | isr_watchdog:
| 30 | isr_adc:
| 31 | reti
| 32 |
| 33 |
| 34 | isr_reset:
| 35 | ldi r16,low(ramend)
| 36 | out spl,r16
| 37 |
| 38 |
| 39 | ldi r16,63 ;alles Ausgänge
| 40 | out ddrb,r16
| 41 | ; wir nutzen R16-R19 als 32 Bit SRG
| 42 | ; R20-R23 als Polynom
| 43 | ; R24 als NULL-Dummy
| 44 | ; http://www.xilinx.com/support/documentation/application_notes/xapp052.pdf
| 45 | ; n=32, Rückführungen von 32,22,2,1
| 46 | ldi r20,3 ;Rückführung 2,1
| 47 | ldi r21,0
| 48 | ldi r22,0x20 ;Rückführung 22
| 49 | ldi r23,0x80 ;Rückführung 32
| 50 |
| 51 | ldi r24,0 ;Dummy für Leerzweig
| 52 |
| 53 | ldi r16,0xaa ;Seed
| 54 |
| 55 | loop:
| 56 | ror R19
| 57 | ror R18
| 58 | ror r17
| 59 | ror r16
| 60 | brcs one
| 61 |
| 62 | ;zero
| 63 | eor r16,r24
| 64 | eor r17,r24
| 65 | eor r18,r24
| 66 | eor r19,r24
| 67 |
| 68 | ldi r25,0b00111000
| 69 | out portb,r25
| 70 | rjmp loop
| 71 |
| 72 | one:
| 73 | eor r16,r20
| 74 | eor r17,r21
| 75 | eor r18,r22
| 76 | eor r19,r23
| 77 |
| 78 | ldi r25,0b00000111
| 79 | out portb,r25
| 80 | rjmp loop
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