;
; MIOS Custom LCD Driver Example for character LCDs
;
; NOTE: this is just a template for LCDs which are different to
; HD44780 (that is natively supported by MIOS -> LCD type #0)
; Note also that this driver only supports a single CLCD
; and no free definable enable (E) line
;
; ==========================================================================
;
; Copyright (C) 2003 Thorsten Klose (tk@midibox.org)
; Licensed for personal non-commercial use only.
; All other rights reserved.
;
; ==========================================================================
;; --------------------------------------------------------------------------
;; Following system variables are given by MIOS and can be directly
;; accessed by the driver. The addresses are defined in mios.h and
;; should not be changed
;;
;; MIOS_GLCD_BUFFER a 8 byte buffer for data transfers
;; MIOS_LCD_OPTION1 contains the first LCD option given by MIOS_LCD_TypeSet
;; MIOS_LCD_OPTION2 contains the second LCD option given by MIOS_LCD_TypeSet
;; MIOS_LCD_CURSOR_POS the current cursor pos of characters (GLCD: multiplied by width)
;; MIOS_GLCD_GCURSOR_X for GLCDs: the current X position of graphical cursor
;; MIOS_GLCD_GCURSOR_Y for GLCDs: the current Y position of graphical cursor
;; MIOS_GLCD_FONT_WIDTH for GLCDs: the fontwidth given by MIOS_GLCD_FontInit
;; MIOS_GLCD_FONT_HEIGHT for GLCDs: the fontheight given by MIOS_GLCD_FontInit
;; MIOS_GLCD_FONT_X0 for GLCDs: the first byte within a char entry
;; MIOS_GLCD_FONT_OFFSET for GLCDs: the byte offset between the characters
;; MIOS_GLCD_FONT_PTRL for GLCDs: pointer to the character table, low-byte
;; MIOS_GLCD_FONT_PTRH for GLCDs: pointer to the character table, high-byte
;; MIOS_LCD_TIMEOUT0 can be used for timeout loops
;; MIOS_LCD_TIMEOUT1 can be used for timeout loops
;; MIOS_GLCD_TMP1 can be used as temporary buffer
;; MIOS_GLCD_TMP2 can be used as temporary buffer
;; MIOS_GLCD_TMP3 can be used as temporary buffer
;; MIOS_GLCD_TMP4 can be used as temporary buffer
;; MIOS_LCD_Y0_OFFSET Y0 offset of LCD
;; MIOS_LCD_Y1_OFFSET Y1 offset of LCD
;; MIOS_LCD_Y2_OFFSET Y2 offset of LCD
;; MIOS_LCD_Y3_OFFSET Y3 offset of LCD
;; MIOS_LCD_CURSOR_POS_REAL unmapped cursor position which has been set with MIOS_LCD_CursorSet
;;
;; Note: the addresses are located in an upper bank and therefore have to
;; be accessed with the BANKED flag. Also the BSR has to be justified
;; before using the registers
;; Example:
;; SET_BSR MIOS_LCD_OPTION1 ; sets BSR to the bank where MIOS_LCD_*
;; ; has been located. You don't need to
;; ; change the BSR for the other LCD registers
;; movf MIOS_LCD_OPTION1, W, BANKED ; get LCD option #1
;;
;; Important: to allow a proper interaction with MIOS applications, you are
;; only allowed to modify MIOS_PARAMETER[123], the mutliplication registers
;; and FSR1. You are not allowed to change TMP[1-5] or FSR0
;; if you need some temporary registers, use the given addresses above or
;; locate them to addresses which are not used by the application
;; --------------------------------------------------------------------------
;; Pins of LC-Display
USER_LCD_LAT_D EQU LATB ; Pin B.7-0
USER_LCD_PORT_D EQU PORTB
USER_LCD_TRIS_D EQU TRISB
USER_LCD_LAT_RW EQU LATD
USER_LCD_PIN_RW EQU 6 ; Pin D.6
USER_LCD_LAT_RS EQU LATD
USER_LCD_PIN_RS EQU 5 ; Pin D.5
USER_LCD_LAT_E EQU LATD ; Pin D.7
USER_LCD_PIN_E EQU 7
;; new names for CLCD registers
USER_LCD_STATUS EQU MIOS_GLCD_TMP1
USER_LCD_SC_CTR EQU MIOS_GLCD_TMP3
#define USER_LCD_STATUS_LCD0_DISABLED 0 ; bit0: if set, first LCD disabled
#define USER_LCD_STATUS_LCD1_DISABLED 1 ; bit1: if set, second LCD disabled -- not provided by this driver!
#define USER_LCD_STATUS_CUR_DISABLED 2 ; bit2: if set, currently selected LCD disabled
#define USER_LCD_STATUS_CUR_LCD 3 ; bit3: if cleared: current LCD is first LCD, else second LCD
;; --------------------------------------------------------------------------
;; This function is called by MIOS when the custom LCD should be initialized
;; In: MIOS_LCD_OPTION1 - contains the first LCD option given by MIOS_LCD_TypeSet
;; MIOS_LCD_OPTION2 - contains the second LCD option given by MIOS_LCD_TypeSet
;; Out: -
;; --------------------------------------------------------------------------
USER_LCD_Init
;; notify that no graphical LCD is connected
bcf MIOS_BOX_CFG0, MIOS_BOX_CFG0_USE_GLCD
movlw 0xf9 ; set only TRISE[2:1] as output
andwf TRISE, F
; (Initialization of Ports: done in Init_Ports)
SET_BSR MIOS_LCD_TIMEOUT1
clrf USER_LCD_STATUS, BANKED
movlw 100 ; 100 ms delay
call MIOS_Delay
bcf USER_LCD_LAT_RW, USER_LCD_PIN_RW ; LCD_WRITE
bcf USER_LCD_LAT_RS, USER_LCD_PIN_RS ; USER_LCD_PIN_RS_0
;; initialize LCD
movlw 0x38
movwf USER_LCD_LAT_D
rcall USER_LCD_Strobe_Set
rcall USER_LCD_Strobe_Clr
movlw 50 ; 50 ms delay
call MIOS_Delay
rcall USER_LCD_Strobe_Set
rcall USER_LCD_Strobe_Clr
movlw 50 ; 50 ms delay
call MIOS_Delay
rcall USER_LCD_Strobe_Set
rcall USER_LCD_Strobe_Clr
movlw 0x08 ; Display Off
rcall USER_LCD_Cmd
movlw 0x0c ; Display On
rcall USER_LCD_Cmd
movlw 0x06 ; Entry Mode
rcall USER_LCD_Cmd
movlw 0x01 ; Clear Display
call USER_LCD_Cmd
bcf MIOS_LCD_TIMEOUT1, 7, BANKED ; everything ok, make sure that LCD_TIMEOUT, bit 7 is cleared
movlw 0x38 ; without these lines the LCD will not work
rcall USER_LCD_Cmd ; correctly after a second USER_LCD_Init
movlw 0x0c
rcall USER_LCD_Cmd
movlw 0x00 ; set cursor to zero pos
rgoto USER_LCD_CursorSet
;; --------------------------------------------------------------------------
;; FUNCTION: USER_LCD_Data
;; DESCRIPTION: sends a data value to the LCD display.<BR>
;; On CLCDs: branch directly to USER_LCD_PrintChar<BR>
;; On GLCDs: ignore this function!
;; IN: data which should be sent
;; OUT: -
;; --------------------------------------------------------------------------
USER_LCD_Data
;; store byte in data latch
movwf USER_LCD_LAT_D
;; store bits 3:2 into port E bits 2:1
rrncf WREG, 0, 0 ;; shift right
movwf LATE ;; store in port E latch
rlncf WREG, 0, 0 ;; shift left, leave WREG as it was!
;; wait until display unbusy
rcall USER_LCD_WaitUnbusy
;; exit if current LCD not available due to timeout
BIFSET USER_LCD_STATUS, USER_LCD_STATUS_CUR_DISABLED, BANKED, return
;; select data register
bsf USER_LCD_LAT_RS, USER_LCD_PIN_RS
;; activate write
bcf USER_LCD_LAT_RW, USER_LCD_PIN_RW
;; strobe and exit
rcall USER_LCD_Strobe_Set
rgoto USER_LCD_Strobe_Clr
;; --------------------------------------------------------------------------
;; FUNCTION: USER_LCD_Cmd
;; DESCRIPTION: sends a command to the LCD display.<BR>
;; On CLCDs: use this function to decode the HD44780 commands if required<BR>
;; On GLCDs: ignore this function!
;; IN: command which should be sent
;; OUT: -
;; --------------------------------------------------------------------------
USER_LCD_Cmd
;; store byte in data latch
movwf USER_LCD_LAT_D
;; store bits 3:2 into port E bits 2:1
rrncf WREG, 0, 0 ;; shift right
movwf LATE ;; store in port E latch
rlncf WREG, 0, 0 ;; shift left, leave WREG as it was!
;; wait until display unbusy
rcall USER_LCD_WaitUnbusy
;; exit if current LCD not available due to timeout
BIFSET USER_LCD_STATUS, USER_LCD_STATUS_CUR_DISABLED, BANKED, return
;; select command register
bcf USER_LCD_LAT_RS, USER_LCD_PIN_RS
;; activate write
bcf USER_LCD_LAT_RW, USER_LCD_PIN_RW
;; strobe and exit
rcall USER_LCD_Strobe_Set
rgoto USER_LCD_Strobe_Clr
;; --------------------------------------------------------------------------
;; This function is NOT called by MIOS, but only used by the custom driver
;; to wait until the LCD is unbusy
;; In: -
;; Out: -
;; --------------------------------------------------------------------------
USER_LCD_WaitUnbusy
;; exit if current LCD not available due to timeout
BIFSET USER_LCD_STATUS, USER_LCD_STATUS_CUR_DISABLED, BANKED, return
;; turn off output drivers
movlw 0xf3 ; set all except TRISB[3:2] as input
iorwf USER_LCD_TRIS_D, F
movlw 0x06 ; set only TRISE[2:1] as input
iorwf TRISE, F
;; select command register
bcf USER_LCD_LAT_RS, USER_LCD_PIN_RS
;; poll busy bit
clrf MIOS_LCD_TIMEOUT0, BANKED
clrf MIOS_LCD_TIMEOUT1, BANKED
bsf USER_LCD_LAT_RW, USER_LCD_PIN_RW ; LCD_READ
USER_LCD_WaitUnbusy_Loop
rcall USER_LCD_Strobe_Clr
incf MIOS_LCD_TIMEOUT0, F, BANKED
skpnz
incf MIOS_LCD_TIMEOUT1, F, BANKED
bz USER_LCD_WaitUnbusy_Disable ; leave loop when LCD_TIMEOUT = 0xff. Up to now bit 7 is set and the LCD
; busy routine will never be called again
rcall USER_LCD_Strobe_Set
IFSET USER_LCD_PORT_D, 7, rgoto USER_LCD_WaitUnbusy_Loop
rcall USER_LCD_Strobe_Clr
USER_LCD_WaitUnbusy_End
;; turn on output drivers again
movlw 0x0c ; set all except TRISB[3:2] as output
andwf USER_LCD_TRIS_D, F
movlw 0xf9 ; set only TRISE[2:1] as output
andwf TRISE, F
return
USER_LCD_WaitUnbusy_Disable
;; disable currently selected LCD
btfss USER_LCD_STATUS, USER_LCD_STATUS_CUR_LCD, BANKED
bsf USER_LCD_STATUS, USER_LCD_STATUS_LCD0_DISABLED, BANKED
btfsc USER_LCD_STATUS, USER_LCD_STATUS_CUR_LCD, BANKED
bsf USER_LCD_STATUS, USER_LCD_STATUS_LCD1_DISABLED, BANKED
rgoto USER_LCD_WaitUnbusy_End
;; --------------------------------------------------------------------------
;; This function is NOT called by MIOS, but only used by the custom driver
;; to set the strobe line to logic-1
;; In: -
;; Out: -
;; --------------------------------------------------------------------------
USER_LCD_Strobe_Set
;; (code for variable E output removed)
bsf USER_LCD_LAT_E, USER_LCD_PIN_E
nop
nop
nop
nop
nop
return
;; --------------------------------------------------------------------------
;; This function is NOT called by MIOS, but only used by the custom driver
;; to set the strobe line to logic-0
;; In: -
;; Out: -
;; --------------------------------------------------------------------------
USER_LCD_Strobe_Clr
;; (code for variable E output removed)
nop
nop
nop
nop
nop
bcf USER_LCD_LAT_E, USER_LCD_PIN_E
return
;; --------------------------------------------------------------------------
;; This function is called by MIOS when the custom LCD should be cleared
;; In: MIOS_LCD_OPTION1 - contains the first LCD option given by MIOS_LCD_TypeSet
;; MIOS_LCD_OPTION2 - contains the second LCD option given by MIOS_LCD_TypeSet
;; Out: -
;; --------------------------------------------------------------------------
USER_LCD_Clear
movlw 0x01
call USER_LCD_Cmd
BIFSET MIOS_LCD_Y2_OFFSET, 7, BANKED, rgoto USER_LCD_Clear2
BIFSET MIOS_LCD_Y3_OFFSET, 7, BANKED, rgoto USER_LCD_Clear2
return
USER_LCD_Clear2
bsf MIOS_LCD_CURSOR_POS, 7, BANKED
movlw 0x01
call USER_LCD_Cmd
bcf MIOS_LCD_CURSOR_POS, 7, BANKED
return
;; --------------------------------------------------------------------------
;; This function is called by MIOS when the cursor should be changed
;; In: MIOS_LCD_OPTION1 - contains the first LCD option given by MIOS_LCD_TypeSet
;; MIOS_LCD_OPTION2 - contains the second LCD option given by MIOS_LCD_TypeSet
;; MIOS_GLCD_CURSOR_X - horizontal cursor position (for GLCDs)
;; MIOS_GLCD_CURSOR_Y - vertical cursor position (for GLCDs)
;; MIOS_LCD_CURSOR_POS - character cursor position (for CLCDs)
;; Out: -
;; --------------------------------------------------------------------------
USER_LCD_CursorSet
SET_BSR MIOS_LCD_CURSOR_POS
movf MIOS_LCD_CURSOR_POS, W, BANKED
iorlw 0x80
rgoto USER_LCD_Cmd
;; --------------------------------------------------------------------------
;; This function is called by MIOS when a character should be print
;; In: WREG - character
;; all other MIOS_*LCD_* registers
;; Out: GLCDs should justify the X/Y cursor position
;; --------------------------------------------------------------------------
USER_LCD_PrintChar
rgoto USER_LCD_Data
;; --------------------------------------------------------------------------
;; FUNCTION: USER_LCD_SpecialCharInit
;; DESCRIPTION: see MIOS_CLCD_SpecialCharInit
;; IN: number of special character (0-7) in WREG
;; pointer to special char pattern in TBLPTR (consists of 8
;; entries for every character-line)
;; OUT: TBLPTR has to be set to next table entry (TBLPTR+=8)
;; --------------------------------------------------------------------------
USER_LCD_SpecialCharInit
;; transfer special character to display
swapf WREG, F
rrf WREG, W
andlw 0x38
iorlw 0x40
rcall USER_LCD_Cmd
SET_BSR USER_LCD_SC_CTR
clrf USER_LCD_SC_CTR, BANKED
USER_LCD_SpecialCharInitLoop
tblrd*+
movf TABLAT, W
rcall USER_LCD_Data
incf USER_LCD_SC_CTR, F, BANKED
BIFCLR USER_LCD_SC_CTR, 3, BANKED, rgoto USER_LCD_SpecialCharInitLoop
goto USER_LCD_CursorSet