AXIOMTEK AX10445 Series, Руководство пользователя

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AX10445 Module Series User
’
s Manual
Application
24
4.3 Demo Program for Turbo Pascal
{ This is a demo program for turbo pascal }
program demo485;
uses crt, dos;
const
pa = $3f8; (* com port data define *)
mask = $ef;
intno = $c;
bufsize = 255; (* buffer size *)
var
rxbuf : array[1..bufsize] of byte; (* receiver buffer *)
ii,i : word; (* index count *)
is_485 : boolean; (* mode flag *)
int_id : word; (* interrupt identification
*)
intbuf : pointer;
(* bios int 14 call *)
procedure int14_0(port,para:word);
inline(
$58/ (* pop ax *)
$5A/ (*pop dx *)
$B4/$00/ (* mov ah,0 *)
$CD/$14); (*int 14 *)
(* interrupt service routine *)
Procedure ch_isr(flags,cs, ip,ax,bx,cx,dx,si,di,ds,es,bp:word);
interrupt;
begin
inline($FB); (* sti *)
int_id :=port[pa+2]; (* get interrupt id. *)
if (int_id >= 4) then (* check received data *)
begin
rxbuf[ii] := port[pa]; (* store into buffer *)
ii :=ii + 1; (* inc index *)
port[$20] :=$20; (* send EOI *)
end;
end;
(* communication port initialization *)
procedure com_init;