u08key.c

MC68HC08JB8 的USB驱动源程序,开发环境是Code wayyior HC08

//============================================================================
// File: U08KEY.C
// Func: Key Input Functions for USB08
// Ver.: 1.01
// Auth: (C)2000,2001 by Oliver Thamm, MCT Elektronikladen GbR
//       http://hc08web.de/usb08
// Rem.: View/Edit this File with TAB-Size=4
// Jan 02 : Adapted for CodeWarrior by Isabelle GIRAUD, Metrowerks Europe 
//============================================================================

#include "hc08jb8.h"
#include "u08key.h"

//-- Definitions -------------------------------------------------------------

// Specification of *active* Key Inputs:
// PTA[4,5,6] = %01110000 = 0x70
// First Key connected to Port Bit 4

#define KEY_MASK 0x70
#define KEY_FIRST 4

//-- Variables ---------------------------------------------------------------

// Var used to track the Key Status

#pragma DATA_SEG SHORT MY_ZEROPAGE
unsigned char KeyState;
#pragma DATA_SEG DEFAULT

//----------------------------------------------------------------------------

void initKey() {

	POCR |= 0x01;		// enable PTA Pullups
	PTA  |= KEY_MASK;	// write 1 to Output Latches
	DDRA |= KEY_MASK;	// output H-Level Pulse
	DDRA &= ~KEY_MASK;	// back to Input
	KBIER = KEY_MASK;	// enable Interrupts
	KBSCR = 0x04;		// reset ACKK (just in case)
	KeyState = 0;		// reset internal Status Var
	}

//----------------------------------------------------------------------------

char getKey(unsigned char x) {

	x += KEY_FIRST-1;	// calculate Bit Position
	x = 1 << x;			// create Bit Mask
	if(KeyState & x)	// test the relevant Status Bit
		return 1;
	return 0;
	}

//----------------------------------------------------------------------------

interrupt void isrKey() {

	KeyState ^= ~(PTA | ~KEY_MASK);
	KBSCR = 0x04;		// reset ACKK (for noise safety only)
	}

//============================================================================