Problem with sci (reception) MC908JL8CPE

Oddie12 — Fri, 03 Jun 2011 04:07:20 GMT

Hi, i need help with the sci, i can send and receive, but i can´t move the data received to the port B.
I try turn off the sci and then move to the port B and it works, but if not the port B show 09h (hexadecimal) (PTB1 = 1 ; PTB3 = 1).
Too i send a character when receipt and i receive 2 characters.
The connection is between the PC and uC, and use the Termite 2.6 for read the characters that sends the uC

I´m using the MC908JL8CPE , sorry for my english, and thanks for everything

Here attached my code:

init:
      mov          #$01,config1         ;Disable WatchDog         
      mov      #$00,config2       
          mov          #$FF,DDRB                        
      mov      #$40,DDRD           
          clr            PORTB               
      clr              PORTD
      mov      #$03,VAR
      clra                            
     
init_SCI:
;***** SCBR: SCP1=0,SCP0=0,SCR2=0,SCR1=1,SCR0=0 *******
      mov      #$02,SCBR            ;Baud Rate register = 9600
     
;***** SCC1: LOOPS=0,ENSCI=1,TXINV=0,M=0,WAKE=0,ILTY=0,PEN=0,PTY=0 *******
      mov      #$40,SCC1             ;Control register 1
     
;***** SCC2: SCTIE=0,TCIE=0,SCRIE=0,ILIE=0,TE=1,RE=1,RWU=0,SBK=0 *******     
      mov      #$0C,SCC2              ;Control register 2 (TE,RE enable)
                                   
;***** SCC3: R8=0,T8=0,ORIE=0,NEIE=0,FEIE=0,PEIE=0 *******           
      mov      #$00,SCC3     ;Control register 3



recepcion:                  
      lda            SCS1     
      brclr      SCRF,SCS1,*
      mov      SCDR,VAR         
      mov      VAR,PORTB
      lda              SCS1
      mov      'R',SCDR
      brclr      SCTE,SCS1,*
      jmp      recepcion

Re: Problem with sci (reception) MC908JL8CPE

JimB — Wed, 08 Jun 2011 16:20:35 GMT

Hi, how are you getting on with this problem? I tried your code in Codewarrior, making minimal changes to get it to assemble (eg to the names of registers) and then tried it in the simulator program. The only thing that really seems wrong is that the 'R' should be #'R'. Apart from that it seems to work fine, so maybe the problem is with the terminal program sending something unexpected as you seem to suspect.

I'm a big fan of the simulator, it is great for seeing exactly what is going on and can even give clues about some aspects that may not be clear in the datasheet for a mcu. Another thing that might be useful to look at with Codewarrior is the processor initialisation feature, which is very helpful. One of the things it would do differently is that it would not enable things (eg SCI) until after it had finished configuring them, although this doesn't seem to matter in your case.

Good luck with the terminal side of things!

topic Re: Problem with sci (reception) MC908JL8CPE in 8-bit Microcontrollers

Problem with sci (reception) MC908JL8CPE

Re: Problem with sci (reception) MC908JL8CPE