Unitech PT630, Руководство программиста

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PT630 Programming Reference Guide Page 15 of 59
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1.5
System Functions ( INT 21H )
1.5.1 Terminate Program
Entry Parameter: AH = 0
Return Value: None
Example:
void TS_exit_program()
{
regs.h.ah=
0;
int86(0x21,&regs,&regs);
}
1.5.2 Read Keypad (wait if no key) and Write to LCD
Entry Parameter: AH = 1
Return Value: AL = 0 – 255 ; ASCII character
Example:
unsigned char TS_stdin()
{
regs.h.ah= 1;
int86(0x21,&regs,&regs);
return(regs.h.al);
}
1.5.3 Write LCD
Entry Parameter: AH = 2
DL = 0 – 255 ; ASCII character
Return Value: None
Example:
void TS_stdout(unsigned char ch)
{
regs.h.ah= 2;
regs.h.dl= ch;
int86(0x21,&regs,&regs);
return;
}
1.5.4 Read RS232 (wait if no character)
Entry Parameter: AH = 3
Return Value: AL = 0 – 255 ; ASCII character
Note: Only for NONE communication protocol
Example:
unsigned char TS_stdaux_in()
{
regs.h.ah= 3;
int86(0x21,&regs,&regs);
return(regs.h.al);
}