/***********************************************************************
 * pport.cpp
 *
 * Parallel port access routines for the Windows environment.  These
 * functions must be linked against dlportio.lib.
 *
 * Bits of the various registers are complemented according to the
 * inversions present on the parallel port itself and the XS40 board.
 ***********************************************************************/

#include <stdafx.h>
#include <dlportio.h>
#include "pport.h"


/***********************************************************************
 * void writeDataReg(unsigned char d)
 *
 * d's value is written to the data register of the given parallel port.
 * Note that bit 7 must be kept high to avoid re-programming the FPGA.
 *
 ***********************************************************************/

void writeDataReg(unsigned char d)
{
   DlPortWritePortUchar(PORT_BASE, 0x80 | (d ^ DATA_MASK));
}


/***********************************************************************
 * unsigned char readStatusReg(void)
 *
 * Returns the value of the given parallel port's status register.
 * The return value is first shifted right by three to eliminate the
 * three "ghost" bits.
 ***********************************************************************/

unsigned char readStatusReg(void)
{
   return (DlPortReadPortUchar(PORT_BASE + STATUS_OFFSET) ^ STATUS_MASK)
           >> 3;
}


/***********************************************************************
 * void writeControlReg(unsigned char c)
 *
 * c's value is written to the control register of the given parallel
 * port.
 ***********************************************************************/

void writeControlReg(unsigned char c)
{
   DlPortWritePortUchar(PORT_BASE + CONTROL_OFFSET, c ^ CONTROL_MASK);
}