MODULE broadcast1;
(*---------------------------------------------------------
File name: broadcast1.pm
Author: AG
Date: 5/23/05 

Problem: This program broadcasts two single variables into 
a chain continuously.

Example of Execution:
	L1:  5  6  5  6  5  6  5  6  5  6  5  6  5  6  5  6

Cycles:
2 assignments
*)
(*----------------------------------------------------------
		CONFIGURATION
----------------------------------------------------------*)
CONST  MAXCELLS=1024; (* MAXCELLS cells in one line *)

CONFIGURATION chain[0..(MAXCELLS - 1)];
CONNECTION
		left: chain [i] -> chain[(i-1) MOD MAXCELLS];
		right: chain[i] -> chain[(i+1) MOD MAXCELLS];
(*----------------------------------------------------------
		VARIABLES
----------------------------------------------------------*)
VAR 
		L0, L1: chain OF INTEGER;
		N, X1, X2, RightLimit: INTEGER;
(*----------------------------------------------------------
		MAIN
----------------------------------------------------------*)
BEGIN
	(*Initialize data *)
	RightLimit:= 16;
	N:= 2;
	X1:= 5;
	X2:= 6;
	(*Prepare Selection *)
	L0:= ID(chain);
	
	IF L0 MOD N = 1 THEN (*select odd positions *)
		L1:= X1;
	ELSE (* L0 MOD N = 0 *) (* select even positions *)
		L1:= X2;
	END; (* IF *)
	(* L1= 5 6 5 6 5 6 5 6 5 6 5 6 5 6 5 6 5 6... *)
	
	(*printing*)
	IF L0 <= RightLimit THEN  
		WriteString("L1: "); WriteInt(L1, 2);WriteLn;
	END; (*IF *)
END broadcast1.