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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 74 | arune | 1 | /* |
| 2 | Precise Delay Functions |
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| 3 | V 0.5, Martin Thomas, 9/2004 |
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| 4 | |||
| 5 | In the original Code from Peter Dannegger a timer-interrupt |
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| 6 | driven "timebase" has been used for precise One-Wire-Delays. |
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| 7 | My loop-approach is less elegant but may be more usable |
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| 8 | as library-function. Since it's not "timer-dependent" |
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| 9 | See also delay.h. |
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| 10 | |||
| 11 | Inspired by the avr-libc's loop-code |
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| 12 | */ |
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| 13 | |||
| 14 | #include <avr/io.h> |
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| 15 | #include <avr/io.h> |
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| 16 | #include <inttypes.h> |
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| 17 | |||
| 18 | #include "delay.h" |
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| 19 | |||
| 20 | void delayloop32(uint32_t loops) |
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| 21 | { |
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| 22 | __asm__ volatile ( "cp %A0,__zero_reg__ \n\t" \ |
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| 23 | "cpc %B0,__zero_reg__ \n\t" \ |
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| 24 | "cpc %C0,__zero_reg__ \n\t" \ |
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| 25 | "cpc %D0,__zero_reg__ \n\t" \ |
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| 26 | "breq L_Exit_%= \n\t" \ |
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| 27 | "L_LOOP_%=: \n\t" \ |
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| 28 | "subi %A0,1 \n\t" \ |
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| 29 | "sbci %B0,0 \n\t" \ |
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| 30 | "sbci %C0,0 \n\t" \ |
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| 31 | "sbci %D0,0 \n\t" \ |
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| 32 | "brne L_LOOP_%= \n\t" \ |
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| 33 | "L_Exit_%=: \n\t" \ |
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| 34 | : "=w" (loops) \ |
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| 35 | : "0" (loops) \ |
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| 36 | ); \ |
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| 37 | |||
| 38 | return; |
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| 39 | } |