/* $Id: comint.h,v 1.5 2004/02/15 23:10:28 ecen2120 Exp $ */

extern void
EnableUART(int device, int baud, char parity);
/* Open interrupt-driven serial communication
 *   On entry-
 *     device=uart number
 *     baud=baud rate desired
 *     parity=parity generation and checking desired:
 *       'E' for even parity
 *       'O' for odd parity
 *       '1' for parity bit always 1
 *       '0' for parity bit always 0
 *       any other value indicates no parity generation or checking
 *     If parity generation and checking is specified, each character
 *     transmitted will contain 7 information bits; otherwise each
 *     character transmitted will contain 8 information bits.
 *   On exit-
 *     Communication is open
 ***/

extern int
SpaceAvailable(int device);
/* Check for space to send characters
 *   On entry-
 *     device=uart number
 *   If communication is not open then on exit-
 *     SpaceAvailable value is undefined
 *   Else if no space is available then on exit-
 *     SpaceAvailable=0
 *   Else on exit-
 *     SpaceAvailable is not 0
 ***/

extern void
SendCharacter(int device, char c);
/* Send a character to the UART
 *   On entry-
 *     device=uart number
 *     c=character to be sent
 *   If communication is open then on exit-
 *     c has been sent to the UART
 *   Else on exit-
 *     Nothing has been done
 ***/

extern int
CharactersAvailable(int device);
/* Check for received characters
 *   On entry-
 *     device=uart number
 *   If communication is not open then on exit-
 *     CharactersAvailable value is undefined
 *   Else if no characters are available then on exit-
 *     CharactersAvailable=0
 *   Else on exit-
 *     CharactersAvailable is not 0
 ***/

extern char
RecvCharacter(int device);
/* Obtain the first available character from the UART
 *   On entry-
 *     device=uart number
 *   If communication is not open or
 *      no characters are available then on exit-
 *     RecvCharacter value is undefined
 *   Else on exit-
 *     RecvCharacter=first available character
 *     First available character is no longer available
 ***/

extern void
DisableUART(int device);
/* Terminate interrupt-driven serial communication
 *   On exit-
 *     Communication is not open
 *     No characters are available
 ***/