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C/C++ Interactive Reference Guide
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C-C++ Interactive Reference Guide.iso
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csource5
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342_01
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i8255f05.c
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C/C++ Source or Header
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1991-02-26
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/*-
* ----------------------------------------------------------------------
* File : I8255F05.C
* Creator : Blake Miller
* Version : 01.00.00 February 1991
* Language : Microsoft C Version 5.1
* Purpose : Intel 8255 Compatible Digital IO Functions
* : 8255 Byte Put Function
* ----------------------------------------------------------------------
*/
#define I8255F05_C_DEFINED 1
#include "I8255FN.H"
#undef I8255F05_C_DEFINED
void I8255_put_byte (I8255DAT *data, int p_num, unsigned char p_dat);
/*- I8255 : Byte Put -------------------------**
* Write one of the bytes in the 8255.
* The port number should be 1 - 3 as follows:
* 1 = Port A, 2 = Port B, 3 = Port C
* Passed:
* pointer : I8255DAT
* integer : port number
* unsigned char : port data
* Returns:
* nothing
* Loads stat with any error ID.
*/
void I8255_put_byte (I8255DAT *data, int p_num, unsigned char p_dat)
{
int padd; /* port address */
/* Make sure the port requested is valid.
* Three ports.
*/
if ( (p_num < 1) || (p_num > 3) ){
data->stat = I8255_ST_BP;
return;
}
/* Decrement the port so we have zero offset.
* port number = ( 0 - 2 )
*/
p_num--;
/* Prepare to output data:
* Obtain port address.
* Save the port data.
*/
switch ( p_num ){
case 0: /* port A */
padd = I8255_PORTA(data->base);
data->adat = p_dat;
break;
case 1: /* port B */
padd = I8255_PORTB(data->base);
data->bdat = p_dat;
break;
case 2: /* port C */
padd = I8255_PORTC(data->base);
data->cdat = p_dat;
break;
default: /* bad port number */
return;
break;
}
chp_portwt ( padd, p_dat );
data->stat = I8255_ST_OK;
}
/*-
* ----------------------------------------------------------------------
* END I8255F05.C Source File
* ----------------------------------------------------------------------
*/