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Nitron LCD Terminal

MON08 Programming and Debugging circuits

Nitron Oszillator trimming

AB32 Board

HC08 Flash programming

HCS08 Controller

HCS12 Controller

HC12 Welcome Kit


Zwobots Display






With a Nitrom 68HC908QY4 and a Hitachi LM052L LC Display I built a little terminal.
The terminal is equipped with a RS232 connector and a debug port, that works with the Motorola User Monitor. I didnīt solderd a level shifter on the board, because I use my little pod, on the controller page or use it directly on a controller. Because the terminal only has to receive characters, I wrote a littele interrupt driven RS232 receive routine. I utilize the KBD interrupt on PTA0 and call the GetbBte ROM routine to receive the character.
The ISR looks like this.


pshh                   ;save H-reg
sei                    ;Disable Interrupts
mov  #%00000010,KBIER  ;disable KB-Int
bclr PTA0,PTA          ;initialize PTA0 for serial comms
jsr GetByte            ;call GetByte at adress $2D6b
sta data               ;store the received character in RAM
mov #%00000100,KBSCR   ;Clear Pending KBD interrupts
mov #%00000001,KBIER   ;enable Keyboard interrupts
cli                    ;enable ints
pulh                   ;get H-reg back

You can find schematics here. lcdschem.gif The software is here lcdterme.asm. It would fit into the 1.5 kB Flash of the 68HC908QY1 or 68HC908QY2 too, but I had the 4 kB Version lying around so I used them.
Another display project is Zwobots Display. This project is programmed n C and uses a hardware SCI.






   © 2005 by Eckhard Gosch •