www.pudn.com > 8255_code_lib.rar > DIOFNC11.C
/*-
* ----------------------------------------------------------------------
* File : DIOFNC11.C
* Creator : Blake Miller
* Version : 01.01.00 February 1991
* Language : Microsoft C Version 5.1
* Purpose : Intel 8255 Compatible Digital IO Functions
* : Port Array Functions
* ----------------------------------------------------------------------
* WARNING : I do not have a multi-port board on which to test
* these functions. The single-port functions work correctly, and I
* wrote these multi-port functions as an extension to those
* single-port functions for those of you with multi-port boards.
* These functions here 'seem' correct, but are not truly debugged.
* ----------------------------------------------------------------------
* Revision History:
* 022891 BVM : Creation
* ----------------------------------------------------------------------
*/
#define DIOFNC11_C_DEFINED 1
#include "malloc.h" /* malloc() free() */
#include "stdio.h" /* NULL definition */
#include "DIOLIB.H"
#undef DIOFNC11_C_DEFINED
static DIODAT *dadat = (DIODAT *)NULL; /* array : base pointer */
static short dasiz = 0; /* array : element count */
static short mxbit = 0; /* array : maximum bit */
short dio_pa_aloc (short);
void dio_pa_free (void);
short dio_pa_setadr (short, short);
short dio_pa_bitput (short, short);
short dio_pa_bitget (short, short *);
short dio_pa_getptr (short, DIODAT **);
short dio_pa_config (short, short, short, short, short);
/*- DIO : Allocate Data Array Space ----------**
* Allocate memory for the DIODAT data array.
* Passed:
* short : number of DIODAT elements to be in array
* Returns:
* short : DIO_ST_OK = OK
* : DIO_ST_NM = No memory available
* : DIO_ST_MA = Existing memory not yet free
*/
short dio_pa_aloc (short danum)
{
/* Memory already in use.
*/
if ( dadat != (DIODAT *)NULL )
return (DIO_ST_MA);
/* Allocate memory.
* Check for failure.
*/
dadat = malloc ( danum * sizeof(DIODAT) );
if ( dadat == (DIODAT *)NULL )
return (DIO_ST_NM);
/* Save count of array elements.
* Default data even though don't know addresses yet.
* Calculate maximum bit for this array size.
*/
dasiz = danum;
for ( danum = 0; danum < dasiz; danum++ ){
dio_init ( &dadat[danum], 0);
}
mxbit = danum * 24;
return (DIO_ST_OK);
}
/*- DIO : Free Data Array Space --------------**
* Allocate memory for the DIODAT data array.
* It does no harm to call this function if the
* memory has not already been allocated.
* Passed:
* short : number of DIODAT elements to be in array
* Returns:
* Nothing
*/
void dio_pa_free (void)
{
if ( dadat != (DIODAT *)NULL ){
dasiz = 0; /* set count to zero */
free ( dadat ); /* free array memory */
}
}
/*- DIO : Set Element Address ----------------**
* Set the 8255 address of one of the array elements.
* Passed:
* short : DIODAT element affected (Base 0)
* short : 8255 base address
* Returns:
* short : DIO_ST_OK = OK
* : DIO_ST_NM = Memory not allocated
* : DIO_ST_BE = Bad element
*/
short dio_pa_setadr (short danum, short basadr)
{
/* Check for errors.
* No memory.
* Bad element number.
* Otherwise assign address.
*/
if ( dasiz == 0 )
return (DIO_ST_NM);
if ( (danum < 0) || (danum >= dasiz) )
return (DIO_ST_BE);
dadat[danum].base = basadr;
dadat[danum].stat = DIO_ST_OK;
return (DIO_ST_OK);
}
/*- DIO : Array Bit Put ----------------------**
* Set/Clear one of the bits in the 8255 port array.
* A state of !0 sets the bit and a state of 0 clears the bit.
* The bit number should be from 0 -> mxbit-1 (Base 0).
* Passed:
* short : bit number
* short : state : TRUE (!0) = SET, FALSE (0) = CLEAR
* Returns:
* short : DIO_ST_OK = OK
* : DIO_ST_NM = Memory not allocated
* : DIO_ST_BB = Bad bit number
*/
short dio_pa_bitput (short bit, short state)
{
short danum;
if ( dasiz == 0 )
return (DIO_ST_NM);
if ( (bit < 0) || (bit >= mxbit) )
return (DIO_ST_BB);
danum = ( bit / 24); /* 8255 array element number */
bit = bit % 24; /* 8255 compensated bit number */
dio_bitput (&dadat[danum], bit, state);
dadat[danum].stat = DIO_ST_OK;
return (DIO_ST_OK);
}
/*- DIO : Array Bit Get ----------------------**
* Read one of the bits in the 8255 port array.
* A state of 1 indicates a set bit and a state of 0
* indicates a clear bit.
* The bit number should be from 0 -> mxbit-1 (Base 0).
* Passed:
* short : bit number
* pointer : short : state : 1 = SET, 0 = CLEAR
* Returns:
* short : DIO_ST_OK = OK
* : DIO_ST_NM = Memory not allocated
* : DIO_ST_BB = Bad bit number
* Loads state with 0 or 1.
*/
short dio_pa_bitget (short bit, short *state)
{
short danum;
if ( dasiz == 0 )
return (DIO_ST_NM);
if ( (bit < 0) || (bit >= mxbit) )
return (DIO_ST_BB);
danum = ( bit / 24); /* 8255 array element number */
bit = bit % 24; /* 8255 compensated bit number */
dio_bitget (&dadat[danum], bit, state);
dadat[danum].stat = DIO_ST_OK;
return (DIO_ST_OK);
}
/*- DIO : Get Array Address ------------------**
* Return address of the DIODAT array.
* Note that NULL is returned if memory not allocated.
* Passed:
* short : element number
* pointer : DIODAT *
* Returns:
* short : DIO_ST_OK = OK
* : DIO_ST_NM = Memory not allocated
* : DIO_ST_BE = Bad element number
*/
short dio_pa_getptr (short danum, DIODAT **diopp)
{
if ( dasiz == 0 )
return (DIO_ST_NM);
if ( (danum < 0) || (danum >= dasiz) )
return (DIO_ST_BE);
*diopp = &dadat[danum];
return (DIO_ST_OK);
}
/*- DIO : Array Element Configure ------------**
* Configure port direction for one of the 8255s in the array.
* Passed:
* short : element number
* short : direction Port A
* short : direction Port B
* short : direction Port C Low
* short : direction Port C High
* Returns:
* short : DIO_ST_OK = OK
* : DIO_ST_NM = Memory not allocated
* : DIO_ST_BE = Bad element number
*/
short dio_pa_config (short danum, short pa_dir, short pb_dir,
short cl_dir, short ch_dir)
{
if ( dasiz == 0 )
return (DIO_ST_NM);
if ( (danum < 0) || (danum >= dasiz) )
return (DIO_ST_BE);
/* Initially set mode to DIO_SET since we are
* going to configure the 8255.
* Then OR in the IO direction bits as appropriate.
*/
dadat[danum].mode = DIO_SET;
if ( pa_dir ) dadat[danum].mode |= DIO_PA_IN;
if ( pb_dir ) dadat[danum].mode |= DIO_PB_IN;
if ( cl_dir ) dadat[danum].mode |= DIO_CL_IN;
if ( ch_dir ) dadat[danum].mode |= DIO_CH_IN;
dio_bput ( dadat[danum].base + DIO_CNTRL, dadat[danum].mode );
dadat[danum].stat = DIO_ST_OK;
return (DIO_ST_OK);
}
/*-
* ----------------------------------------------------------------------
* END DIOFNC11.C Source File
* ----------------------------------------------------------------------
*/