-- new file anme: pb1so2.vhd
-- file name: pb1scrdout.vhd
-- protection block1
-- input : forward input 
-- input : reverse input
-- input : A+FAC  A+(F.A.C)(input for this block coming from the 
--		   output of firing angle calculation block).
-- input : A-FAC  A-(F.A.C)(input for this block coming from the
--         output of firing angle calculation block).
-- output: two outputs are comingb from this block are 
--		   FOR1 AND REV1  and going to the scr firing forward 
--		   and reverse  buffers (all outputs of these buffers are 
--		   active low .
--		   FOR1 and REV1 are active low
------------------------------------------------------------- 		  
--    			inputs						outputs 
-------------------------------------------------------------
--		FORC	REVC	A+FAC A-FAC 	FOR1	REV1
-------------------------------------------------------------	
--		1		1		 0		0		1		1
--		1		0		 1		0		0		1
--		1		0		 0		1		0		1
--		1		0		 1		1		1		1
--		0		1		 0		0		1		0
--		0		1		 1		0		1		0
--		0		1		 0		1		1		0
--		0		1		 1		1		1		1
--		1		1		 0		1		1		1
--		1		1		 1		0		1		1
--		1		1		 1		1		1		1
-------------------------------------------------------------	
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;


entity pb1so2  is

port(
		FORC,REVC,APFAC,ANFAC : in std_logic ;
		FOR1,REV1 : out std_logic );

end pb1so2 ;

architecture BEHAV of pb1so2 is

begin 
PBLOCK1: process(FORC,REVC,APFAC,ANFAC)
begin
		
		IF FORC = '0' THEN 
			IF REVC = '0' THEN  
				FOR1 <= '1' ;
				REV1 <= '1';
	
		 	ELSIF  REVC = '1'  THEN
				IF APFAC = '1' THEN
					IF  ANFAC ='0' THEN
						FOR1 <= '1'  ;   -- ENABLE  FORWARD BUFFER CTRL 
						REV1 <= '0'	 ;	 -- DISABLE REVERSE BUFFER CTRL 	 
					ELSIF ANFAC ='1' then
						FOR1 <= '1' ;	  -- DISABLE FORWARD BUFFER CONTROL 
						REV1 <= '1';     -- DISABLE REVERSE BUFFER CTRL
					END IF;
				ELSIF APFAC = '0' THEN
					IF ANFAC ='1' THEN
						FOR1 <= '1';	 -- ENABLE FORWARD BUFFER CTRL
						REV1 <= '0';	 -- DISABLE REVERSE BUFFER CTRL 
					ELSIF ANFAC ='0' THEN 
						FOR1 <= '1';       -- DISBALE FORWARD BUFFER CTRL
						REV1 <= '0';	   -- DISABLE REVERSE BUFFER CTRL	
					END IF;
				END IF ;

			
			END IF ;
			 
		ELSIF  FORC = '1' THEN  
			 IF REVC = '1' THEN
				FOR1 <= '1' ;
				REV1 <= '1' ;
			  ELSIF REVC = '0' THEN 							
				IF APFAC = '1' THEN
					IF  ANFAC ='0' THEN
						FOR1 <= '0'  ;   -- ENABLE  FORWARD BUFFER CTRL 
						REV1 <= '1'	 ;	 -- DISABLE REVERSE BUFFER CTRL 	 
					ELSIF ANFAC ='1' then
						FOR1 <= '1' ;	  -- DISABLE FORWARD BUFFER CONTROL 
						REV1 <= '1';     -- DISABLE REVERSE BUFFER CTRL
					END IF;
				ELSIF APFAC = '0' THEN
					IF ANFAC ='1' THEN
						FOR1 <= '0';	 -- ENABLE FORWARD BUFFER CTRL
						REV1 <= '1';	 -- DISABLE REVERSE BUFFER CTRL 
					ELSIF ANFAC ='0' THEN 
						FOR1 <= '0';       -- DISBALE FORWARD BUFFER CTRL
						REV1 <= '1';	   -- DISABLE REVERSE BUFFER CTRL	
					END IF;
				END IF ;

			
			   END IF ;
			END IF ;
				
END PROCESS PBLOCK1 ;

END BEHAV ;