Hi Folks
I am trying to use 2 x 40 character LCD with HC908GP32 running with a 32.768kHz crystal.
The code below (in assembler) work fine in monitor mode, but, not when programmed into the micro.
I would like to use the busy flag from the LCD so that the code is faster and looks neater.
If anyone has any ideas I would like to hear them.
Note that I am only using Port C with an LED to try to work out where the program actually gets to.
When programmed, it looks like that LCD powers up correctly, then nothing.
Have fun
$BASE 10T ; sets number base to 10 unless otherwise specified.
; Setting labels for the ports
PORTA EQU $0000 ; address of PORTA
PORTB EQU $0001 ; address of PORTB
PORTC EQU $0002 ; address of PORTC
PORTD EQU $0003 ; address of PORTD
PORTE EQU $0008 ; address of PORTE
DDRA EQU $0004 ; data direction control for PORTA
DDRB EQU $0005 ; data direction control for PORTB
DDRC EQU $0006 ; data direction control for PORTC
DDRD EQU $0007 ; data direction control for PORTD
DDRE EQU $000C ; data direction control for PORTE
PTAPUE EQU $000D ; Pullup enable register for PORTA
;PTBPUE Pullup enable register for PORTB does not exist
PTCPUE EQU $000E ; Pullup enable register for PORTC
PTDPUE EQU $000F ; Pullup enable register for PORTD
;PTEPUE Pullup enable register for PORTE does not exist
CONFIG1 EQU $1F ; Configuration register address for COP etc
; Setting the labels for the clock speed of the chip
PCTL EQU $36 ; PLL control register
PBWC EQU $37 ; PLL bandwidth control register
PMSH EQU $38 ; PLL multiplier select register high
PMSL EQU $39 ; PLL multiplier select register low
PMRS EQU $3A ; PLL VCO range select register
PMDS EQU $3B ; PLL reference divider select register
; ******
; Setting other register labels
TBCR EQU $001C ; Timebase Control Register
ADSCR EQU $3C ; A/D Converter Status Control Register
ADR EQU $3D ; A/D data Register
; Uses PORT A data lines for the LCD and PORT E for control lines.
; R/W is on PORT D (0-write to, 1-read from LCD)
; PORT E
; Bit 0 will be the Enable line
; Bit 1 will be the RS (register select) line
; ie data (1) or function (0) mode
LCD EQU $0000 ; For sending info to LCD, actually PORT A
LCD_CONTROL EQU $0008 ; PORT E, controls LCD, the following values are sent here to
; operate LCD.
LCD_D_ON EQU %00000011 ; Sets PORT A value as character for LCD.
LCD_D_OFF EQU %00000010 ; Sends PORT A value as character to LCD.
LCD_F_ON EQU %00000001 ; Sets PORT A value as function command for LCD.
LCD_F_OFF EQU %00000000 ; Sends PORT A value as function command to LCD.
org $FFFE ; Sets the reset vector for programmed chip
FDB INIT
org $9000 ; program loads into memory from location specified
INIT LDA #$00 ; Simply initialisation values
LDX #$00
MOV #$31,CONFIG1 ; MCU runs w/o LVI and COP support
LCD_SETUP
MOV #$FF,DDRA ; Set PORTA as output
MOV #$FF,DDRC ; Set PORTC as output
MOV #$FF,DDRD ; Set PORTD as output
MOV #$03,DDRE ; Set PORT E as output (3 because there are only 2 bits).
MOV #$00,PORTC
MOV #$00,PORTD
LDA #$00
LOOP1 LDX #$00
DBNZX *
COM PORTC
DBNZA LOOP1
; IMPORTANT to set LCD as 4 bit, must send ONLY control code '0010' on the 4 data lines,
; THEN start sending the full 8 bit data/control codes in 2x4 bit nibbles, high nibble first!!!
MOV #$20,LCD ; Sets LCD to 4 bit data
MOV #LCD_F_ON,LCD_CONTROL ; Do NOT use the sub routine LCD_FUNCTION here,
NOP ; as it will send 2x4 bit nibbles.
MOV #LCD_F_OFF,LCD_CONTROL
LDA #$00
LOOP2 LDX #$00
DBNZX *
COM PORTC
DBNZA LOOP2
MOV #$28,LCD ; Sets display as 4 bit data, 2 line, 5x7 matrix
;JSR LCD_FUNCTION
LDA #$00
LOOP3 LDX #$00
DBNZX *
COM PORTC
DBNZA LOOP3
MOV #$01,LCD ; Clears display and sends cursor home
JSR LCD_FUNCTION
MOV #$02,LCD ; Sends cursor and display home
JSR LCD_FUNCTION
MOV #$0F,LCD ; Turns display ON, cursor ON, Blink ON.
JSR LCD_FUNCTION
LDHX #LCD_OK ; Load HX regs with location of message
LDA #'^' ; Load A with ascii value of '^'
TEXT_1 MOV X+,LCD ; Copy the contents of location HX to LCD (PORT A). Note, also increments X.
CMP LCD ; Compare LCD with A
BEQ END_LCD_SETUP ; Exits text routine if reach end-of-text marker '^'
JSR LCD_DATA ; Puts text onto LCD screen
JMP TEXT_1
END_LCD_SETUP
JMP *
;*******
LCD_FUNCTION
LDA LCD
STA LCD ; Moves accumulator to location LCD, loads high 4 bits into the LCD screen
MOV #LCD_F_ON,LCD_CONTROL
NOP
MOV #LCD_F_OFF,LCD_CONTROL
JSR LCD_DELAY
NSA ; nibble swaps the accumulator
STA LCD ; Moves accumulator to location LCD, loads high 4 bits into the LCD screen
MOV #LCD_F_ON,LCD_CONTROL
NOP
MOV #LCD_F_OFF,LCD_CONTROL
JSR LCD_DELAY
RTS
;*******
LCD_DATA
PSHA
LDA LCD ; Moves accumulator to location LCD, loads high 4 bits into the LCD screen
MOV #LCD_D_ON,LCD_CONTROL
NOP
MOV #LCD_D_OFF,LCD_CONTROL
JSR LCD_DELAY
NSA ; nibble swaps the accumulator
STA LCD ; Moves accumulator to location LCD, loads high 4 bits into the LCD screen
MOV #LCD_D_ON,LCD_CONTROL
NOP
MOV #LCD_D_OFF,LCD_CONTROL
JSR LCD_DELAY
PULA
RTS
;*******
LCD_DELAY
MOV #$00,DDRA ; Set PORT A as input
MOV #$FF,PORTD ; Sets LCD to read mode
BRSET 7,PORTA,*
MOV #$00,PORTD ; Sets LCD to write mode
MOV #$FF,DDRA ; Set PORTA to output
RTS
;*******
Org $8000
LCD_OK EQU $8000
DB '<LCD OK>^'
Posted: Sun Dec 12, 2004 10:30 pm
Not to sure but don't you need to reset the stack pointer.
Posted: Mon Dec 13, 2004 8:18 am
am reasonably sure that the stack pointer does not need initilizing and as I only do one set of push/pulls, reseting the stack pointer should not be an issue.
Regardless, the program works with a timed LCD_DELAY and the same push/pulls.
Posted: Mon Dec 13, 2004 7:13 pm
Hi,
What's your configuration (ports level + XTAL) in Monitor mode ?
Cheers
Posted: Fri Dec 17, 2004 11:16 am
Helllo,
in your delay routine you have to togggle the ECLK Pin everytime you read the dataport to get actual data. So you have to use a loop ta wait until D7 is cleared.
LCD_DELAY
MOV #$00,DDRA ; Set PORT A as input
MOV #$FF,PORTD ; Sets LCD to read mode
---> toggle ECLK here
BRSET 7,PORTA,* and go back to LCD_DELAY to read again
MOV #$00,PORTD ; Sets LCD to write mode
MOV #$FF,DDRA ; Set PORTA to output
RTS
Posted: Thu Apr 07, 2005 6:58 am
Thanks for the help folks, it works wonderfully now.
I finally found the time to sit down and work through it all. There were a pile of things that just weren't quite right, mostly with the way I was thinking about it.
Have fun
Message Edited by RChapman on 01-19-2006 04:47 PM
