A PIC C Code Wizard

// Timer2.cpp : implementation file
//

#include "stdafx.h"
#include "piccpc.h"
#include "Timer2.h"
#include "math.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CTimer2 property page

IMPLEMENT_DYNCREATE(CTimer2, CPropertyPage)

CTimer2::CTimer2() : CPropertyPage(CTimer2::IDD)
{
	//{{AFX_DATA_INIT(CTimer2)
	m_dDesiredOverflow = 0.0;
	//}}AFX_DATA_INIT
}

CTimer2::~CTimer2()
{
}

void CTimer2::DoDataExchange(CDataExchange* pDX)
{
	CPropertyPage::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CTimer2)
	DDX_Control(pDX, IDC_T2_POSTSCALER, m_cT2Postscaler);
	DDX_Control(pDX, IDC_T2_RESOLUTION, m_cT2Resolution);
	DDX_Text(pDX, IDC_T2_COUNTER, m_dDesiredOverflow);
	DDX_Control(pDX, IDC_T2_OVERFLOW, m_sInfo);
	//}}AFX_DATA_MAP
}


BEGIN_MESSAGE_MAP(CTimer2, CPropertyPage)
	//{{AFX_MSG_MAP(CTimer2)
	ON_CBN_SELCHANGE(IDC_T2_RESOLUTION, OnSelchangeT2Resolution)
	ON_CBN_SELCHANGE(IDC_T2_POSTSCALER, OnSelchangeT2Postscaler)
	ON_EN_CHANGE(IDC_T2_COUNTER, OnChangeT2Counter)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CTimer2 message handlers

BOOL CTimer2::OnSetActive() 
{
	//update timer2
	CheckDlgButton( IDC_T2_ENABLE, PICInfo.sfr.T2CON&0x04 );
	UpdateT2ResolutionList();
	UpdateT2Postscaler();
	UpdateT2Interrupt();

	return CPropertyPage::OnSetActive();
}

BOOL CTimer2::OnKillActive() 
{
	if ( !CPropertyPage::OnKillActive() )
		return FALSE;
	
	return TRUE;
}

void CTimer2::UpdateT2ResolutionList() {
	m_cT2Resolution.ResetContent();
	CString s;
	for ( int i=1;i<=16;i*=4 ) {
		s.Format( "%G", i*PICInfo.dInstructionTime*1000.0 );
		m_cT2Resolution.AddString( s );
	}
	m_cT2Resolution.SetCurSel( PICInfo.sfr.T2CON&0x03 );
}

void CTimer2::UpdateT2Postscaler() {
	m_cT2Postscaler.SetCurSel( (PICInfo.sfr.T2CON&0x78)>>3 );
}

void CTimer2::OnSelchangeT2Resolution() 
{
	PICInfo.sfr.T2CON &= 0xFC;
	PICInfo.sfr.T2CON |= m_cT2Resolution.GetCurSel();
	UpdateT2Interrupt();
}

void CTimer2::UpdateT2Interrupt() {
	if ( !UpdateData() )
		return;
	if ( m_dDesiredOverflow < PICInfo.dInstructionTime*50000.0 && m_dDesiredOverflow != 0.0 ) {
		m_dDesiredOverflow = PICInfo.dInstructionTime*50000.0;
		UpdateData( FALSE );
	}
	DWORD pr2_off = MAXBYTE - PICInfo.sfr.PR2;
	PICInfo.dwT2Offset = 0;
	PICInfo.dwT2Counter = 0;
	CString s;
	GetDlgItemText( IDC_T2_RESOLUTION, s );
	double fres = atof( s );
	DWORD tmp = (DWORD)(m_dDesiredOverflow/fres);
	m_dDesiredOverflow = tmp*fres;
	int p = ((PICInfo.sfr.T2CON&0x78)>>3) + 1; //m_cT2Postscaler.GetCurSel() + 1;
	for ( unsigned int i=MAXBYTE+1;i>0;i-- ) {
		double y = fres*i;
		double f = fmod( m_dDesiredOverflow, y );
		double x = fabs(f-y);
		if ( f == 0.0 || x<1e-13 ) {
			PICInfo.dwT2Offset = MAXBYTE - i + 1;
			PICInfo.dwT2Counter = (DWORD)(m_dDesiredOverflow/(fres*i*p));
			if ( 0 == PICInfo.dwT2Counter )
				PICInfo.dwT2Counter = 1;
			s.Format( "Interrupt every/total:\t%fms, %fms\n"
				"Timer offset:\t\t%u\n"
				"Timer counter:\t\t%u",
				i*fres*p,
				((256-pr2_off-PICInfo.dwT2Offset)*fres)*p*PICInfo.dwT2Counter,
				PICInfo.dwT2Offset,
				PICInfo.dwT2Counter );
			m_sInfo.SetWindowText( s );
			break;
		}
	}

	//fv = fv*p*(256 - (MAXBYTE-PICInfo.sfr.PR2));
	//s.Format( "Timer interrupt every: %Gms\n", fv );
}

void CTimer2::OnSelchangeT2Postscaler() 
{
	PICInfo.sfr.T2CON &= 0x07;
	PICInfo.sfr.T2CON |= (m_cT2Postscaler.GetCurSel()<<3);
	UpdateT2Interrupt();
}

void CTimer2::OnChangeT2Counter() 
{
	CheckDlgButton( IDC_T2_INTEN, 1 );
}