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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 886 | killagreg | 1 | #ifndef _FIFO_H_ |
| 2 | #define _FIFO_H_ |
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| 3 | |||
| 4 | #include <avr/io.h> |
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| 5 | #include <avr/interrupt.h> |
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| 6 | |||
| 7 | // the fifo object |
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| 8 | typedef struct |
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| 9 | { |
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| 10 | uint8_t volatile count; // # number of characters in FIFO |
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| 11 | uint8_t size; // buffer size |
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| 12 | uint8_t *pread; // read pointer |
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| 13 | uint8_t *pwrite; // write pointer |
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| 14 | uint8_t read2end, write2end; // number of characters for buffer overflow for read/write pointers |
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| 15 | } fifo_t; |
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| 16 | |||
| 17 | /* |
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| 18 | The initialization of the FIFO sets the read/write pointers etc.. |
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| 19 | The FIFO uses the buffer 'buf' which byte length must 'size'. |
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| 20 | */ |
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| 21 | extern void fifo_init (fifo_t*, uint8_t* buf, const uint8_t size); |
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| 22 | |||
| 23 | /* |
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| 24 | Puts a byte into the FIFO. Returns 1 on success ans 0 in case of FIFO overflow. |
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| 25 | */ |
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| 26 | extern uint8_t fifo_put (fifo_t*, const uint8_t data); |
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| 27 | |||
| 28 | /* |
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| 29 | Get the next byte out of the FIFO. If the FIFO is empty the function blocks |
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| 30 | until the next byte is put into the FIFO. |
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| 31 | */ |
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| 32 | extern uint8_t fifo_get_wait (fifo_t*); |
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| 33 | |||
| 34 | /* |
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| 35 | Get the next byte from the FIFO as int. Returns -1 if the FIFO is empty. |
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| 36 | */ |
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| 37 | extern int16_t fifo_get_nowait (fifo_t*); |
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| 38 | |||
| 39 | |||
| 40 | /* |
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| 41 | The same like fifo_put |
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| 42 | */ |
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| 43 | static inline uint8_t _inline_fifo_put (fifo_t *f, const uint8_t data) |
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| 44 | { |
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| 45 | if (f->count >= f->size) |
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| 46 | return 0; |
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| 47 | |||
| 48 | uint8_t * pwrite = f->pwrite; |
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| 49 | |||
| 50 | *(pwrite++) = data; |
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| 51 | |||
| 52 | uint8_t write2end = f->write2end; |
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| 53 | |||
| 54 | if (--write2end == 0) |
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| 55 | { |
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| 56 | write2end = f->size; |
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| 57 | pwrite -= write2end; |
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| 58 | } |
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| 59 | |||
| 60 | f->write2end = write2end; |
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| 61 | f->pwrite = pwrite; |
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| 62 | |||
| 63 | uint8_t sreg = SREG; |
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| 64 | cli(); |
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| 65 | f->count++; |
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| 66 | SREG = sreg; |
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| 67 | |||
| 68 | return 1; |
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| 69 | } |
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| 70 | |||
| 71 | /* |
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| 72 | Get the next byte from FIFO. Before this functionis called |
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| 73 | it must be checked that there is a byte in the FIFO to get. |
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| 74 | */ |
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| 75 | static inline uint8_t _inline_fifo_get (fifo_t *f) |
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| 76 | { |
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| 77 | uint8_t *pread = f->pread; |
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| 78 | uint8_t data = *(pread++); |
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| 79 | uint8_t read2end = f->read2end; |
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| 80 | |||
| 81 | if (--read2end == 0) |
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| 82 | { |
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| 83 | read2end = f->size; |
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| 84 | pread -= read2end; |
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| 85 | } |
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| 86 | |||
| 87 | f->pread = pread; |
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| 88 | f->read2end = read2end; |
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| 89 | |||
| 90 | uint8_t sreg = SREG; |
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| 91 | cli(); |
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| 92 | f->count--; |
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| 93 | SREG = sreg; |
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| 94 | |||
| 95 | return data; |
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| 96 | } |
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| 97 | |||
| 98 | #endif /* _FIFO_H_ */ |