Inp32

[esepich]

Early in my code I have this:

#define Inp32 inb 

Then I have this:

/*trap the clock line*/
do {
	e=Inp32(PORT);
} while( (e & 32) !=0);
/*store the value*/

My questions are these. Is Inp32 being replaced by inb here:

e=Inp32(PORT);

Also here:

while( (e & 32) !=0

What is the purpose of the "e & 32"? What would could it possibly be calculating?

Thanks!



P.S. The entire function I am working with looks like this:

/*** readInterface() ***/
char * readInterface() {

char *cardRaw; /* keep this abstract*/
int e, i;

if( (cardRaw = (char *) malloc(240)) == NULL) {
printf("Error: goParse(): Cannot malloc space for cardRaw\n");
exit(1);
}

for(i=0;i<240;i++)
cardRaw[i]=0;

printf("Waiting for Card\n");

for(i=0;i<240;i++) {

/*trap the clock line*/
do {
	e=Inp32(PORT);
} while( (e & 32) !=0);

/*store the value*/
cardRaw[i]=e;

do {
	e=Inp32(PORT);
} while( (e & 32) != 32);
/*done trapping the clock line*/

}

/* stripe it to a bitstream*/
for(i = 0;i<240;i++) {
	cardRaw[i] = (cardRaw[i] & 16);
	if(cardRaw[i]==0) {
		cardRaw[i]=1;
	} else {
		cardRaw[i]=0;
	}
}

/* return the bitstream */
return cardRaw;
}//readinterface 

[johny10151981]

the binary value of decimal 32 is b'100000'. Now whatever value e contains will be And with b'100000'. If the and operation value return 32 then process will stop right away, continue otherwise