Thread: Embedded programming

hi guys....

I am writing a program. In this program, i have a function which is universal. I am using the GPIO to do serial data sending to several devices connected to my MCU using several pins on a port. The problem now is if this function is universal, how do i pass the pins that i want to the function? i du not want to do the same function for different pins,it will be a waste of space.

Assuming that the function will look like this

Code:

    void DataSend(unsigned char data)
     {
       int a;     
       for (a = 0;a<8 a++)
       {
             PORTA.Pin0 = 0;  // this will generate the low clock pulse
             PORTA.Pin1 = data & 0x01; //this will push the data out 
                                                       //bit by bit
             data >>=1;
             PORTA.Pin0 = 1  //this will generate high clock pulse
      }    
    }

If i want to make PORTA.Pinx as universal and i want to use other pin with this function...is it possible?

can i do the following?

Code:

    void DataSend(unsigned char data, (dunno what type to use) CLKpin ,(dunno what type to use) DATApin )
     {
       int a;     
       for (a = 0;a<8 a++)
       {
             CLKpin = 0;  // this will generate the low clock pulse
             DATApin = data & 0x01; //this will push the data out 
                                                       //bit by bit
             data >>=1;
             CLKpin = 1  //this will generate high clock pulse
      }    
    }

if in the main i call the function as following

Code:

    DATASend('S', PORTA.PIN2,PORTA.pin3)

will this work as if the following?

Code:

    PORTA.Pin2 = 0;

and

Code:

    PORTA.Pin3 = data & 0x01;

As if i am latching the PORTA pin 2 and 3?

Please advise also the type i shuld declare for the pins in the function

thanks

Code:

typedef unsigned char byte;


#define PTA                             _PTA.Byte
#define PTA_PTA0                        _PTA.Bits.PTA0
#define PTA_PTA1                        _PTA.Bits.PTA1
#define PTA_PTA2                        _PTA.Bits.PTA2
#define PTA_PTA3                        _PTA.Bits.PTA3
#define PTA_PTA4                        _PTA.Bits.PTA4
#define PTA_PTA5                        _PTA.Bits.PTA5
#define PTA_PTA6                        _PTA.Bits.PTA6
#define PTA_PTA7                        _PTA.Bits.PTA7

PORTA.Pin0 is the same with PTA_PTA0.

I dun understand how this can be done? can you show me? Thanks

Thanks Dave.

By the way, can you tell me when to use & and when to use &&. I'm a bit confuse. Let say if i want to check for whether a pin is high do i

Code:

if (PORT && PINMASK)

or

Code:

if (PORT & PINMASK)

Is the following

Code:

DATAport &= ~DATApin; // push a zero out

similar with

Code:

DATAport = DATAport  &&  ~DATApin; // push a zero out

or with the following

Code:

DATAport = DATAport  &  ~DATApin; // push a zero out

Did i confuse u? Please don't tell me to read the FAQ as i have already read it but I am still confused.