Digital Input Operations

SetPinsDigitalIn		Configure selected pins as digital inputs.
Read		Read from a selected port.
ReadBits		Read selected bits (pins) from a port.

Thiese operations are available either as functions or macros. The advantage of the macro format is that it avoids function call overhead.

Macros

The macros incorporate the target port into the macro name.

These are the digital input macros associated with Port A.

mPORTASetPinsDigitalIn(unsigned int bits)
mPORTARead()
mPORTAReadBits(unsigned int bits)

Similar definitions exist for the other ports. For example,

mPORTAReadBits(unsigned int bits);
mPORTBReadBits(unsigned int bits);
mPORTCReadBits(unsigned int bits);
mPORTDReadBits(unsigned int bits);
mPORTEReadBits(unsigned int bits);
mPORTFReadBits(unsigned int bits);
mPORTGReadBits(unsigned int bits);

Function Calls

void PORTSetPinsDigitalOut(IoPortId portId, unsigned int bits);
unsigned int PORTRead( );
unsigned int PORTReadBits(IoPortId portId, unsigned int bits);

where

 typedef enum {
         IOPORT_A,
         IOPORT_B,
         IOPORT_C,
         IOPORT_D,
         IOPORT_E,
         IOPORT_F,
         IOPORT_G,
         IOPORT_NUM
         }IoPortId;

Examples

1. Define pins RD2 and RD0 as Inputs:

        #define PORT IOPORT_D
        #define PINS BIT_2 | BIT_0
        PORTSetPinsDigitalIn(PORT, PINS);
   

   or

       mPORTDSetPinsDigitalIn(BIT_2 | BIT_0);
   

2. Read bits RB2 and RB4:

       n = PORTReadBits(IO_PORT_B, BIT_2 | BIT_4)
   

   or

       n = mPORTBToggleBits(BIT_2 | BIT_4);
   

Reference

Maintained by John Loomis, last updated 18 July 2008