ST ST7 - Page 277

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9 - A Carrier-current System for domestIc Remote Control
case 24 :
case 25 :
/* First 3 half cycles must have a pulse (start condition) */
if ( ! CarrierDetected )
CycleNumber=1; /* Reset the whole process if
incorrect header. */
break ;
case 4 : /* 4th half cycle must have no pulse ; end of start */
case 26 :
if ( CarrierDetected )
CycleNumber=1; /* Reset the whole process if
incorrect header. */
break ;
case 5 : /* Receive one of the four bits of house code */
case 27 :
TempHouseCode=0; /*First, initialize house code
value. */
case 7 :
case 9 :
case 11 :
case 29 :
case 31 :
case 33 :
TempHouseCode >>= 1 ; /* Shift right by one bit */
if ( CarrierDetected )
TempHouseCode |= 8 ; /* Set most-significant bit to one */
break ; /* House code has four bits */
case 6 :
case 8 :
case 10 :
case 12 : /* Check that the next even bit sent is the complement
of the odd one. */
case 28 :
case 30 :
case 32 :
case 34 :
if(((TempHouseCode&8)!=0)==CarrierDetected )
CycleNumber=1; /* Reset the whole process if
incorrect check bit. */
break ;
case 13 : /* Receive one of the five bits of Key code */
case 35 :
TempKeyCode = 0 ; /* First, initialize Key code value. */
case 15 :
case 17 :
case 19 :
case 21 :
case 37 :
case 39 :
case 41 :