TTL "LCDTest (Lab 5)" ****************************************************************** * 1) HEADER block - overall info about the program * Project name: LCDTest * Author(s): Alex and Travis * Date: 4 Oct 2012 * Description: Writes 'hi' to the screen ****************************************************************** ****************************************************************** CODE EQU $2000 ;where our code can begin on EVB VPUTCHAR EQU $EE86 ;send character in B to output device CR EQU $0D ;Carriage Return PORTA EQU $0000 tenths EQU $3000 ;reserve a memory byte for tenth of seconds seconds EQU $3001 ;reserve a memory byte for seconds tens EQU $3002 ****************************************************************** ****************************************************************** * 4) CODE section - actual program code * * This is all set-up. Output welcome message to the terminal, * * Print "Ultimate Watch" to the LCD, and check for the initial * * Button press * ****************************************************************** ORG CODE ;tell assembler where to begin object code ;main program body follows Main ldaa #LINIT ;set accumulator to "LINIT" value 0 jsr LCD ;initialize LCD ldx #Title ;load x with the string ldaa #LWRSTR ;load A with the address of the write string subroutine jsr LCD ;execute LWRSTR ldx #Greet ;Point X at the greeting message jsr PUTS ;Output the greeting message ldx #256+0 ;Point to second line (256) + first column (0) ldaa #LGOTO ; jsr LCD ;Point the cursor there ldab #0 ; ldaa #LWRDEC ; jsr LCD ;Output 0 jsr LCD ;Output another 0 ldab #':' ;Load B with a colon to be output ldaa #LWRCHR ;Output colon to the screen jsr LCD ;Do it ldab #0 ; ldaa #LWRDEC ; jsr LCD ;Output 1 more 0 clr tens ; clr seconds ;Clear each variable clr tenths ; Loop movb PORTA, $3100 ;Load Accumulator A with the values of Port A ldaa $3100 ANDA #%10000000 ;Mask with $80 to watch only PA7 bne Loop ;If it is still high, loop. Debounc cmpb #20 ;Wait 20ms to ensure proper debouncing beq Clock ;When debounced, start the clock dbl ldx #0 ;1ms loop dex ; cpx #10000 ; beq dbl ; incb ;Increment debounce counter bra Debounc ; **************************************************************************** * The code following this is all run after the button is pushed initially * * but before it starts the stopwatch part of the program * **************************************************************************** Clock movb PORTA, $3100 ;Load Accumulator A with the values of Port A ldaa $3100 ANDA #%10000000 ;Is it still pushed? bne Clock ;If not, check again ldx #256+0 ;Point to second line (256) + first column (0) ldaa #LGOTO ; jsr LCD ;Point to first character, second line ldab tens ;load b with tens counter ldaa #LWRDEC ;get ready to print tenths to fourth character, second row jsr LCD ;do it ldab seconds ;load b with seconds counter ldaa #LWRDEC ;get ready to print tenths to fourth character, second row jsr LCD ;do it ldab #':' ;Load B with a colon to be output ldaa #LWRCHR ;Output colon to the screen jsr LCD ;Do it ldab tenths ;load b with tenths counter ldaa #LWRDEC ;get ready to print tenths to fourth character, second row jsr LCD ;do it ldd #99 ;If so, get ready to delay 100ms jsr DelayN ;Delay 100ms ldaa tenths ;Check the tenths counter cmpa #9 ;Is it ten? beq secondi ;If so, branch to seconds incrementer tenthsi ldaa tenths ;Increment tenths counter inca ; staa tenths ; bra Clock ;Output and check button status secondi clra staa tenths ;clear tenths counter ldaa seconds cmpa #9 ;Is seconds 10? beq tensi ;If so, branch to tens incrementer ldaa seconds ; inca ;Otherwise, increment seconds staa seconds ; bra Clock ;Output and check button status tensi clra ;Clear seconds staa seconds ; ldaa tens ; inca ;Increment tens staa tens ; bra Clock ;Output and check button status quit ldx #Exit jsr PUTS swi ;return to monitor on EVB PUTS ldab 0,x ;get 1 char from string beq PSDONE ;done if terminating null jsr PUTCHAR ;output this char inx ;advance X to next char bra PUTS ;continue PSDONE rts ;done, return to caller ; single character (in B) output routine PUTCHAR pshx ;save caller's X ldx VPUTCHAR ;fetch address of monitor rtn jsr 0,X ;call monitor rtn. pulx ;restore caller's X rts DelayN bsr Delay1 ;go delay 1 millisecond dbne D,DelayN ;dec 'N' & continue till zero rts * Delay1: delay 1 millisecond via software, * assumes F=24 MHz (and no interrupts) * all registers preserved for caller Delay1 pshx ;2~ preserve registers used here ldx #5997 ;2~ iterations of Dloop for 1ms. Dloop dex ;1~ ] bne Dloop ;3~ ] 5997 * 4~ = 23988~ pulx ;3~ recover used registers rts ;5~ 23988 + 12 = 24000~ = 1ms. ; constant data definitions (FCB,FDB,FCC)... Title FCC "Ultimate Watch" FCB 0 Greet FCC "Welcome to the stopwatch program. Press and hold the button to start the clock." FCB 0 Exit FCC "Thanks, have a good day." FCB CR,CR,CR, 0 ****************************************************************** #include 'LCDdriver.asm' ; tell assembler end of assembly source code END