;Sending "YES" to Hyperterminal (or Tera Terminal) via Serial COM0 (SCI0) on HCS12 MCU Module
;HCS12 MPU Modules come with USB-BDM and ready to be used with CodeWarrior IDE

;In HCS12 MCU modules, RAM address is from $1000-3FFF 
;We use RAM addresses starting at $1000 for scratch pad (variables) and $3FFF for Stack

;Modfied from Example 10-3 in HCS12 textbook by Mazidi & Causey

;On the Project Board, we have a serial COM port with DB-9 connector.
;The Serial COM port on Project Board is connected to the TX0 and RX0 (SCI0) of HCS12 permanently via a MAX232-compatible chip
;Serial COM PORT on Project Board is accessible by the HCS12 MCU Module via jumper called COM_SEL. 
;The COM_SEL jumper is located in front of the DB-9 connector and allows the MON08 or COM selection..
;MAKE SURE the jumper is set for the COM instead of MON08 in the COM_SEL jumper of Project Board before running this program.
;MAKE SURE 4 jumpers for COM_EN on the Project Board are also set. The COM_EN jumpers are located next to DB-9 connector.   

;In CodeWarrior, make sure you are in TBDML Mode before downloading     
;Press F7 (to Make), then F5(Debug) to downLOAD,and F5 once more to start the program execution
   

        ABSENTRY Entry        ; for absolute assembly: mark this as application entry point
    
;Include derivative-specific definitions 
		INCLUDE 'mc9s12dt256.inc'     ;CPU used by HCS12 MCU Module 
 

;code section
      ORG   $4000     ;Flash ROM address 
Entry:
	    LDS   #$4000    ;Stack
      
             
    	LDAA	#$0		
     	STAA  SCI0BDH    	
	    LDAA	#13		
     	STAA  SCI0BDL    ;4MHz/2=2MHz, 2MHz/16=125,000 and 125,000/9600=13 	
     	LDAA  #0	   	
     	STAA	SCI0CR1	
     	LDAA  #$0C	   	
     	STAA	SCI0CR2	
     	
OVER	LDAA  #'Y'		
	    JSR	TRANS
	    LDAA  #'E'		
	    JSR	TRANS
	    LDAA  #'S'		
	    JSR TRANS
	    LDAA  #' '		
	    JSR TRANS
	    
	    BRA	OVER
;----------		
TRANS 
HERE: BRCLR	SCI0SR1, $80, HERE	
  	  STAA	SCI0DRL	
	    RTS		                  
 
;-------------------

            
;**************************************************************
;*                 Interrupt Vectors                          *
;**************************************************************
      ORG   $FFFE
      DC.W  Entry     ;Reset Vector. CPU wakes here and it is sent to start of the code at $4000