1 | //
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2 | // Cforall Version 1.0.0 Copyright (C) 2017 University of Waterloo
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3 | //
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4 | // The contents of this file are covered under the licence agreement in the
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5 | // file "LICENCE" distributed with Cforall.
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6 | //
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7 | // devicedriver.cfa --
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8 | //
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9 | // Author : Peter A. Buhr
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10 | // Created On : Sat Mar 16 15:30:34 2019
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11 | // Last Modified By : Peter A. Buhr
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12 | // Last Modified On : Sat Jun 17 09:11:56 2023
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13 | // Update Count : 94
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14 | //
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15 |
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16 | #include <fstream.hfa>
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17 | #include <coroutine.hfa>
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18 |
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19 | enum Status { CONT, MSG, ESTX, ELNTH, ECRC };
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20 |
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21 | coroutine Driver {
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22 | Status status;
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23 | char * msg, byte;
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24 | }; // Driver
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25 |
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26 | void ?{}( Driver & d, char * m ) { d.msg = m; } // constructor
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27 |
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28 | Status next( Driver & d, char b ) with( d ) { // called by interrupt handler
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29 | byte = b; resume( d ); return status; // resume coroutine at last suspend
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30 | } // next
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31 |
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32 | void checkCRC( Driver & d, unsigned int sum ) with( d ) {
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33 | suspend;
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34 | unsigned short int crc = byte << 8; // sign extension over written
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35 | suspend;
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36 | // prevent sign extension for signed char
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37 | status = (crc | (unsigned char)byte) == sum ? MSG : ECRC;
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38 | } // checkCRC
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39 |
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40 | void main( Driver & d ) with( d ) {
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41 | enum { STX = '\002', ESC = '\033', ETX = '\003', MaxMsg = 64 };
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42 | msg: for () { // parse message
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43 | status = CONT;
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44 | unsigned int lnth = 0, sum = 0;
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45 | while ( byte != STX ) suspend;
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46 | emsg: for () {
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47 | suspend;
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48 | choose ( byte ) { // process byte
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49 | case STX:
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50 | status = ESTX; suspend; continue msg;
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51 | case ETX:
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52 | break emsg;
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53 | case ESC:
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54 | suspend;
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55 | } // choose
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56 | if ( lnth >= MaxMsg ) { // buffer full ?
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57 | status = ELNTH; suspend; continue msg;
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58 | } // if
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59 | msg[lnth++] = byte;
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60 | sum += byte;
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61 | } // for
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62 | msg[lnth] = '\0'; // terminate string
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63 | checkCRC( d, sum ); // refactor CRC check
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64 | suspend;
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65 | } // for
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66 | } // main
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67 |
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68 | int main() {
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69 | char msg[65], byte;
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70 | Driver driver = { msg };
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71 |
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72 | sin | nlOn; // read newline (all) characters
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73 | eof: for () { // read until end of file
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74 | sin | byte; // read one character
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75 | if ( eof( sin ) ) break eof; // eof ?
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76 | choose( next( driver, byte ) ) { // analyse character
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77 | case CONT: ;
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78 | case MSG: sout | "msg:" | msg;
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79 | case ESTX: sout | "STX in message";
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80 | case ELNTH: sout | "message too long";
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81 | case ECRC: sout | "CRC failure";
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82 | } // choose
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83 | } // for
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84 | } // main
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85 |
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86 | // Local Variables: //
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87 | // compile-command: "cfa -g -Wall -Wextra devicedriver.cfa" //
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88 | // End: //
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