Sample Code

• MAX+PlusII Code (Altera FPGA)
  --Synchronous State Machine
  --Makes use of the STD system clock of 4Mhz
  --Variables used
  --int - interrupt from switch
  --iack -interrrupt acknowledge from processor
  
  SUBDESIGN intsm18a
  (
  inpulse, /reset, int,PCI,/INTAK :INPUT;
  /irq :OUTPUT;
  
  )
  
  VARIABLE
  --define INPUT variables with active low signals
  reset,INTAK :NODE;
  
  --define state machine
  sm: MACHINE WITH STATES (s0,s1,s2,s3);
  
  BEGIN
  --equations for INPUT variables with active low signals
  reset = !/reset;
  INTAK=!/INTAK;
  --equations for state machine clock
  sm.clk = inpulse;
  sm.reset = reset;
  --description of state machine
  CASE sm IS
  
  WHEN s0=>
  /irq = VCC;
  IF int THEN sm = s1;
  ELSE sm = s0;
  END IF;
  
  WHEN s1=>
  /irq = GND;
  IF (PCI & INTAK) THEN sm = s2;
  ELSE sm = s1;
  END IF;
  
  WHEN s2=>
  /irq = GND;
  IF INTAK THEN sm=s2;
  ELSE sm=s3;
  END IF;
  
  WHEN s3 =>
  /irq = VCC;
  IF int THEN sm=s3;
  ELSE sm=s0;
  END IF;
  END CASE;
  
  END;

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• C++ Linked List Example
  
  //Implementor for linklist.hpp
  #include "luclist.hpp"
  #include
  #include
  #include
  
  listClass::listClass():Head(NULL)
  {
  }
  
  int listClass::ListSize(ptrType& Head)
  {
  
  int counter = 0;
  ptrType Tail = Head; //Tail points to beggining of list
  if (Tail->Next != NULL)
  do
  {
  Tail = Tail->Next;
  counter++;
  }
  while (Tail->Next != NULL);
  return(counter);
  
  }
  
  void listClass::Addtofront (int counter,ptrType& Head)
  {
  ptrType NewPointer;
  NewPointer = new node;
  NewPointer->Next = Head; //NewPointer now points to Pointer
  
  Head = NewPointer; //Head now points to NewPointer
  NewPointer->Item = counter;
  }
  
  void listClass::Addtoend(int counter, ptrType& Head)
  {
  ptrType Current = new node;
  ptrType Tail = Head; //Tail points to beggining of list
  
  while (Tail->Next != NULL)
  {
  Tail = Tail->Next;
  //This get's Tail to last element
  }
  
  
  Tail->Next = Current;
  Current->Item = counter;
  Current->Next = NULL;
  }
  
  
  void listClass::Deletefront(ptrType& Head)
  {
  ptrType Current;
  Current = Head;
  Head = Current->Next;
  delete Current;
  Current = NULL;
  }
  
  
  void listClass::PrintList(ptrType Head)
  {
  ptrType Current;
  Current = Head; //copies head into current
  if(Current != NULL) //from p185
  {
  cout << "Current->Item = " << Current->Item < PrintList(Current->Next);
  return;
  }
  getchar();
  }
  

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• Microchip 16F84 DAQ With RS-232 Interface
  
  include
  
  ;********************************************************************************
  ;*Programmer-Lucius Perreault *
  ;*06/05/00 *
  ;*Description: *
  ;*This program will read data in from an a/d converter serially and then convert *
  ;*the information into a 4-bit BCD code. The code will then be transmitted *
  ;*serially at a 4600 baud rate to an output. *
  ;********************************************************************************
  
  
  
  
  ;-------------------------------------------------------------------------------
  ;Registers
  Data_Reg equ H'20'
  counter1 equ H'21'
  TRANSMIT equ H'22' ;DATA to be transmitted serially
  TRANSCOUNT equ H'23' ;# of bits to be transmitted
  BAUDCOUNT equ H'24' ;used for my baud rate delay
  H_Byte equ H'25' ;Hi byte of my input data
  L_Byte equ H'26' ;Lo byte of my input data
  temp equ H'27'
  R2 equ H'28' ;LSB of my BCD code
  R1 equ H'29' ;CSB of my BCD code
  R0 equ H'30' ;MSB of my BCD code
  count equ H'31'
  
  ;-------------------------------------------------------------------------------
  ;Constants
  
  constant RA0=D'0' ;Data in from A/D
  constant RA1=D'1' ;400kHz clock out
  constant RA2=D'2' ;Power Swich
  constant RA3=D'3' ;Gain Control
  constant RA4=D'4'
  constant RB0=D'0'
  constant RB1=D'1' ;!Chip Select of A/D
  constant RB2=D'2'
  constant RB3=D'3'
  constant RB4=D'4'
  constant RB5=D'5'
  constant RB6=D'6' ;transmit data to RS-232 @4800 baud rate
  constant RB7=D'7'
  
  ;-------------------------------------------------------------------------------
  Start
  call Initalize_Ports
  Temporary
  bsf PORTB,RB1 ;Unselect the A/D chip
  call Get_Data_ADC ;get my data
  movf Data_Reg,W ;W must contain data to transmit before I call Start_Data
  movwf L_Byte
  call B2_BCD
  movf R1,W
  call Start_Data
  movf R0,W
  call Start_Data
  movlw H'0D'
  call Start_Data
  
  goto Temporary
  ;-------------------------------------------------------------------------------
  Initalize_Ports
  
  clrf PORTA ;clear contents of PORTA
  bsf STATUS,RP0 ;select bank 1
  movlw 0x01 ;Set up porta
  ;RA0 = data receive(input)
  ;RA1 = clock out (output)
  ;RA2 = Power Switch (output)
  ;RA3 = Gain Control (output)
  movwf TRISA
  bcf TRISB,RB1 ;!Chipselect of A/D
  bcf TRISB,RB6 ;data out for RS-232 transmission
  bcf STATUS,RP0 ;bank 0
  return
  ;-------------------------------------------------------------------------------
  ;Note: CHIPSELECT->(CLOCKPULSE->READBIT)*8
  Get_Data_ADC
  ;btfsc PORTA,0 ;wait until you get a start bit
  ;goto Get_Data_ADC
  movlw 8 ;there are 8 bits to be read in
  movwf counter1
  bcf PORTB,RB1 ;assert !ChipSelect pin
  Get_Next_Bit
  Clock_Pulse
  
  
  bsf PORTA,RA1 ;pgt
  nop ;duty cycle
  bcf PORTA,RA1 ;ngt
  
  btfss PORTA,RA0
  bcf Data_Reg,7
  btfsc PORTA,RA0
  bsf Data_Reg,7
  rlf Data_Reg
  decfsz counter1
  goto Get_Next_Bit
  bsf PORTB,RB1 ;don't need Chip Selected anymore
  return
  
  ;-------------------------------------------------------------------------------
  Clock_Pulse_version1
  ;This Subroutine will Pulse RA0 which is connected to my clock input on the AD
  ;It will include my settling time for data on the NGT
  bsf PORTA,RA1
  nop
  bcf PORTA,RA1
  return
  
  ;-------------------------------------------------------------------------------
  Delay_5us
  ;1uS instruction = 1Mhz operating time = 4Mhz/4
  ;I will clock at 400kHZ\
  ;3nops(1us)+1return(2us) = 5us
  ;1/5uS = 200kHz *2(hi/lo) = 400khz clock
  nop
  nop
  nop
  return
  
  
  
  
  ;-------------------------------------------------------------------------------
  ;Send out data to PORTC bit 6 MSB First (NEW)
  Baud_Delay
  ;1/4800 = 208.3 uS
  ;I used 4800 baud rate because that is what were gonna need for
  ;Johns serial transmission as well(thinking ahead!!!).
  
  
  movlw D'40' ;52,37
  movwf BAUDCOUNT ;
  Baud_Decrement
  nop
  nop
  decfsz BAUDCOUNT
  goto Baud_Decrement
  return
  
  Start_Data
  movwf TRANSMIT ;W contains the data to be transmitted already
  movlw H'09'
  movwf TRANSCOUNT
  bcf PORTB,6 ;low for start bit
  
  Transmit_Data
  call Baud_Delay
  rrf TRANSMIT ;Transmit contains character to go out serial
  btfsc STATUS,C
  bsf PORTB,6
  btfss STATUS,C
  bcf PORTB,6
  decfsz TRANSCOUNT
  goto Transmit_Data
  
  Stop_Data
  call Baud_Delay ;used because I Delay at the beginning of Transmit_Data
  bsf PORTB,6 ;changed from porta,6 to portb,6
  call Baud_Delay ;Hold DX hi for a 1/baud
  End_Transmit
  return
  
  ;-------------------------------------------------------------------------------
  B2_BCD
  bcf STATUS,C ;Clear the carry bit
  movlw .16
  movwf count
  clrf R0
  clrf R1
  clrf R2
  
  Loop16
  rlf L_Byte,F
  rlf H_Byte,F
  rlf R2,F
  rlf R1,F
  rlf R0,F
  
  decfsz count,F
  goto adjDEC
  RETLW 0
  
  adjDEC
  movlw R2
  movwf FSR
  call adjBCD
  
  movlw R1
  movwf FSR
  call adjBCD
  
  movlw R0
  movwf FSR
  call adjBCD
  
  goto Loop16
  
  adjBCD
  movlw 3
  addwf 0,W
  movwf temp
  btfsc temp,3 ;test if result >7
  movwf 0
  movlw H'30'
  addwf 0,W
  movwf temp
  btfsc temp,7
  movwf 0
  RETLW 0
  
  end
  

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