LCD.ASM was
adapted from Microchip application note AN587 by Norm
Cramer. It provides interface routines to an industry
standard 2
line by 20
character display module. The code is
for a PIC16C84
but should
work on any PIC16CXX running at 4MHz.
If you find
bugs, problems or want to tell the author how great
a job he
has done, you can contact Norm via e-mail:
cramer@iamerica.net
cramer@dseg.ti.com
Files:
LCD.ASM The routines themselves
LCD.H Some definitions required by
LCD.ASM
LCD.HEX Hex file produced by MPASM 1.31
P16C84.INC Microchip supplied header file for the
16C84
README.TXT You're reading it
History:
;*****************************************************************************************************
;
; Program:
lcd.asm
;
; This
program interfaces to an industry standard 2 line by 20 character display
; module.
The program assembles for 4-bit data interface. LCD_DATA is the port which
; supplies
the data tothe LCD, while LCD_CNTL is the port that has the control lines
; ( E, RS,
R_W ). The data is transfer on the high
nibble of the port ( PORT<7:4> ).
;
; Target:
PIC16C84 - But should work on any PIC16CXX running at 4Mhz
;
; Note: To
change the clock speed, the delays at the end of the source file need to be
changed.
;
;
References:
; Addapted from the Microchip AN587 code.
; OPTREX data sheet.
; Also referenced the following web pages:
;
http://www.iaehv.nl/users/pouweha/lcd.htm
;
http://www.paranoia.com/~filipg/HTML/LINK/F_LCD_tech.html
;
http://hobbes.king.ac.uk/matt/pic
; Andrew Warren's QBasic program for
calculating delays.
;
;
; History
;
Author Date Comments
;
Microchip
;
; Norm
Cramer
; contents
of the lower portion of the output register and the
; output
register TRIS. Changed the examples to
include a table
;
definition using the "dt" compiler directive. Added delay
;
subroutines for testing. Changed
Check_Busy to Wait_Busy and
; added a
Check_Busy that returns 0 if not busy, ff if busy.
; Modified
to meet my programming standards for easy maint.
;
;
ERRORLEVEL -302
Processor 16C84
Radix HEX
EXPAND
include <p16c84.inc>
include <lcd.h>
;
;
LCD_DATA EQU
PORTB
LCD_DATA_TRIS EQU
TRISB
;
;
LCD_CNTL EQU
PORTA
LCD_CNTL_TRIS EQU
TRISA
;
;
;
; LCD
Display Commands and Control Signal names.
;
E EQU
3 ; LCD Enable control line
R_W EQU
1 ; LCD Read/Write control
line
RS EQU
2 ; LCD Register Select
control line
;
;
cblock 0x00c
Temp1, Temp, Char, r1,
r2, r3, r4
endc
;
org _ResetVector ; RESET vector location
RESET:
goto Start
;
; This is
the Periperal Interrupt routine. Should NOT get here
;
page
;
org _IntVector ; Interrupt vector location
ERROR1:
bcf STATUS, RP0 ; Bank 0
goto ERROR1
;
;
;
Start: ; POWER_ON Reset
(Beginning of program)
clrf STATUS ; Do initialization (Bank 0)
clrf INTCON
bsf STATUS, RP0 ; Bank 1
clrf TRISA ; RA5 - 0 outputs
movlw 0xF0 ;
movwf TRISB ; RB7 - 4 inputs, RB3 - 0 outputs
bsf OPTION_REG, NOT_RBPU ; Disable PORTB pull-ups
bcf STATUS, RP0 ; Bank 0
clrf PORTA ; ALL PORT output should output Low.
clrf PORTB
;
page
;
call LCD_Init ; Set up the LCD Module
;Send a
message the hard way
movlw 'M'
call Send_Char
movlw 'i'
call Send_Char
movlw 'c'
call Send_Char
movlw 'r'
call Send_Char
movlw 'o'
call Send_Char
movlw 'c'
call Send_Char
movlw 'h'
call Send_Char
movlw 'i'
call Send_Char
movlw 'p'
call Send_Char
movlw LINE2 ; Address DDRam first character,
second line
call Send_Cmd
;Demonstration
of the use of a table to output a message
movlw 0 ; Table address of start of
message
dispmsg:
movwf Temp1 ; Temp1 holds start of message
address
call Table
andlw 0FFh
btfsc STATUS,Z ; Check if at end of message (zero
returned at end)
goto out
call Send_Char ; Display character
movf Temp1,w ; Point to next character
addlw 1
goto dispmsg
out:
loop:
goto loop ; Stay here forever
;
page
;
Table:
addwf PCL,f ; Jump to character
dt "This is a test line!" ; 20
Character string terminated with a 0
Table_End:
retlw 0
;
; Check to
ensure table doesn't cross a page boundary.
if ( (Table & 0x0FF) >=
(Table_End & 0x0FF) )
MESSG
"Warning - User Definded: Table crosses page boundry in computed
jump"
endif
;
;*******************************************************************
;* The LCD
Module Subroutines *
;*******************************************************************
;
;*******************************************************************
;*SendChar
- Sends character to LCD *
;*This
routine splits the character into the upper and lower *
;*nibbles
and sends them to the LCD, upper nibble first. *
;*******************************************************************
;
Send_Char
movwf Char ; Character to be sent is in W
call Wait_Busy ; Wait for LCD to be ready
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movf Char,w
andlw 0xF0 ; Get upper nibble
iorwf LCD_DATA,F ; Send data to LCD
bcf LCD_CNTL, R_W ; Set LCD to write
bsf LCD_CNTL, RS ; Set LCD to data mode
bsf LCD_CNTL, E ; toggle E for LCD
bcf LCD_CNTL, E
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
swapf Char,W
andlw 0xF0 ; Get lower nibble
iorwf LCD_DATA,F ; Send data to LCD
bsf LCD_CNTL, E ; toggle E for LCD
bcf LCD_CNTL, E
return
;
page
;
;*******************************************************************
;* Send_Cmd
- Sends command to LCD *
;* This routine
splits the command into the upper and lower *
;* nibbles
and sends them to the LCD, upper nibble first. *
;*******************************************************************
Send_Cmd
movwf Char ; Character to be sent is in W
call Wait_Busy ; Wait for LCD to be ready
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movf Char,w
andlw 0xF0 ; Get upper nibble
iorwf LCD_DATA,F ; Send data to LCD
bcf LCD_CNTL,R_W ; Set LCD to write
bcf LCD_CNTL,RS ; Set LCD to command mode
bsf LCD_CNTL,E ; toggle E for LCD
bcf LCD_CNTL,E
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
swapf Char,W
andlw 0xF0
; Get lower nibble
iorwf LCD_DATA,F ; Send data to LCD
bsf LCD_CNTL,E ; toggle E for LCD
bcf LCD_CNTL,E
return
;
page
;
;*******************************************************************
;* This
routine checks the busy flag, returns when not busy *
;* Affects:
*
;* Temp - Returned with busy/address *
;*******************************************************************
;
Wait_Busy
bsf STATUS, RP0 ; Select Register page 1
movlw 0xf0 ; Set port to input
iorwf LCD_DATA_TRIS,W ; Only set upper half of
port
movwf LCD_DATA_TRIS
bcf STATUS, RP0 ; Select Register page 0
bcf LCD_CNTL, RS ; Set LCD for Command mode
bsf LCD_CNTL, R_W ; Setup to read busy flag
bsf LCD_CNTL, E ; Set E high
bcf LCD_CNTL, E ; Set E low
movf LCD_DATA, W ; Read upper nibble busy flag, DDRam
address
andlw 0xF0 ; Mask out lower nibble
movwf Temp
bsf LCD_CNTL, E ; Toggle E to get lower nibble
bcf LCD_CNTL, E
swapf LCD_DATA, w ; Read lower nibble busy flag, DDRam
address
andlw 0x0F ; Mask out upper nibble
iorwf Temp,W ; Combine nibbles
btfsc Temp, 7 ; Check busy flag, high = busy
goto Wait_Busy ; If busy, check again
bcf LCD_CNTL, R_W
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
bcf STATUS, RP0 ; Select Register page 0
return
;
page
;
;*******************************************************************
;* This
routine checks the busy flag, returns ff if busy 00 if not *
;*
busy. Temp will contain the current
address. *
;*
*
;* Affects:
*
;* Temp - Returned with busy/address *
;*******************************************************************
;
Check_Busy
bsf STATUS, RP0 ; Select Register page 1
movlw 0xf0 ; Set port to input
iorwf LCD_DATA_TRIS,W ; Only set upper half of
port
movwf LCD_DATA_TRIS
bcf STATUS, RP0 ; Select Register page 0
bcf LCD_CNTL, RS ; Set LCD for Command mode
bsf LCD_CNTL, R_W ; Setup to read busy flag
bsf LCD_CNTL, E ; Set E high
bcf LCD_CNTL, E ; Set E low
movf LCD_DATA, W ; Read upper nibble busy flag, DDRam
address
andlw 0xF0 ; Mask out lower nibble
movwf Temp
bsf LCD_CNTL, E ; Toggle E to get lower nibble
bcf LCD_CNTL, E
swapf LCD_DATA, w ; Read lower nibble busy flag, DDRam
address
andlw 0x0F ; Mask out upper nibble
iorwf Temp,W ; Combine nibbles
btfsc Temp, 7 ; Check busy flag, high = busy
goto Busy_Exit ; If busy exit with busy flag set
bcf LCD_CNTL, R_W
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
bcf STATUS, RP0 ; Select Register page 0
retlw 0x00
Busy_Exit:
bcf LCD_CNTL, R_W
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
bcf STATUS, RP0 ; Select Register page 0
retlw 0xff
;
page
;
; Initilize
the LCD Display Module
;
LCD_Init:
bcf LCD_CNTL, E ; Clear all controll lines
bcf LCD_CNTL, RS
bcf LCD_CNTL, R_W
call Delay15000 ; Wait for 15ms for LCD to get powered up
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movlw 0x030 ; Command for 4-bit interface high
nibble
iorwf LCD_DATA,F ; Send data to LCD
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
BCF STATUS, RP0 ; Select Register page 0
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
call Delay4100 ; Delay for at least 4.1ms before
continuing
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
call Delay100 ; delay for at least 100usec before
continuing
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
call Wait_Busy ; From here on, the Busy Bit will be
valid.
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movlw 0x020 ; Command for 4-bit interface high
nibble (Really an 8bit command but
; lower 4 bits are don't care at this point)
iorwf LCD_DATA,F ; Send data to LCD
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
movlw FUNCTION_SET ; Send the function set command 4-bit I/F,
Font, Number of lines
call Send_Cmd ; Can now use the Send_Cmd routine
since Busy Bit Valid and in 4bit mode.
movlw DISP_OFF
call Send_Cmd
movlw DISP_ON
call Send_Cmd
movlw ENTRY_INC
call Send_Cmd
; LCD
Module is now initalized
return
;
; Delay
routines. These routines need to be
modified to work with the particular PIC configuration
;
used. For test purposes, they are
instruction count delays based on 4Mhz PIC.
The delays are a
; little
longer than advertised but close enough for testing.
;
Delay4100:
movlw d'252'
movwf r1
movlw 4
movwf r2
movlw 1
movwf r3
movlw 1
movwf r4
delay_loop:
nop
decfsz r1,f
goto delay_loop
decfsz r2,f
goto delay_loop
decfsz r3,f
goto delay_loop
decfsz r4,f
goto delay_loop
return
Delay100:
movlw d'22'
movwf r1
movlw 1
movwf r2
movlw 1
movwf r3
movlw 1
movwf r4
goto delay_loop
Delay15000:
movlw d'156'
movwf r1
movlw 15
movwf r2
movlw 1
movwf r3
movlw 1
movwf r4
goto delay_loop
end
;*****************************************************************************************************
;
; Program:
lcd.asm
;
; This
program interfaces to an industry standard 2 line by 20 character display
; module.
The program assembles for 4-bit data interface. LCD_DATA is the port which
; supplies
the data tothe LCD, while LCD_CNTL is the port that has the control lines
; ( E, RS,
R_W ). The data is transfer on the high
nibble of the port ( PORT<7:4> ).
;
; Target:
PIC16C84 - But should work on any PIC16CXX running at 4Mhz
;
; Note: To
change the clock speed, the delays at the end of the source file need to be
changed.
;
;
References:
; Addapted from the Microchip AN587 code.
; OPTREX data sheet.
; Also referenced the following web pages:
;
http://www.iaehv.nl/users/pouweha/lcd.htm
;
http://www.paranoia.com/~filipg/HTML/LINK/F_LCD_tech.html
;
http://hobbes.king.ac.uk/matt/pic
; Andrew Warren's QBasic program for
calculating delays.
;
;
; History
;
Author Date Comments
;
Microchip 05-10-94 Original Code (File name was
LM032L.ASM)
;
; Norm
Cramer 04-22-96 Modified to only use 4 bit interface
and to not destroy the
; contents of the lower
portion of the output register and the
; output
register TRIS. Changed the examples to
include a table
;
definition using the "dt" compiler directive. Added delay
;
subroutines for testing. Changed
Check_Busy to Wait_Busy and
; added a
Check_Busy that returns 0 if not busy, ff if busy.
; Modified to meet my
programming standards for easy maint.
;
;
ERRORLEVEL -302
Processor 16C84
Radix HEX
EXPAND
include <p16c84.inc>
include <lcd.h>
;
;
LCD_DATA EQU
PORTB
LCD_DATA_TRIS EQU
TRISB
;
;
LCD_CNTL EQU
PORTA
LCD_CNTL_TRIS EQU
TRISA
;
;
;
; LCD
Display Commands and Control Signal names.
;
E EQU
3 ; LCD Enable control line
R_W EQU
1 ; LCD Read/Write control
line
RS EQU
2 ; LCD Register Select
control line
;
;
cblock 0x00c
Temp1, Temp, Char, r1,
r2, r3, r4
endc
;
org _ResetVector ; RESET vector location
RESET:
goto Start
;
; This is
the Periperal Interrupt routine. Should NOT get here
;
page
;
org _IntVector ; Interrupt vector location
ERROR1:
bcf STATUS, RP0 ; Bank 0
goto ERROR1
;
;
;
Start: ; POWER_ON Reset
(Beginning of program)
clrf STATUS ; Do initialization (Bank 0)
clrf INTCON
bsf STATUS, RP0 ; Bank 1
clrf TRISA ; RA5 - 0 outputs
movlw 0xF0 ;
movwf TRISB ; RB7 - 4 inputs, RB3 - 0 outputs
bsf OPTION_REG, NOT_RBPU ; Disable PORTB pull-ups
bcf STATUS, RP0 ; Bank 0
clrf PORTA ; ALL PORT output should output Low.
clrf PORTB
;
page
;
call LCD_Init ; Set up the LCD Module
;Send a
message the hard way
movlw 'M'
call Send_Char
movlw 'i'
call Send_Char
movlw 'c'
call Send_Char
movlw 'r'
call Send_Char
movlw 'o'
call Send_Char
movlw 'c'
call Send_Char
movlw 'h'
call Send_Char
movlw 'i'
call Send_Char
movlw 'p'
call Send_Char
movlw LINE2 ; Address DDRam first character,
second line
call Send_Cmd
;Demonstration
of the use of a table to output a message
movlw 0 ; Table address of start of
message
dispmsg:
movwf Temp1
; Temp1 holds start of
message address
call Table
andlw 0FFh
btfsc STATUS,Z ; Check if at end of message (zero
returned at end)
goto out
call Send_Char ; Display character
movf Temp1,w
; Point to next character
addlw 1
goto dispmsg
out:
loop:
goto loop ; Stay here forever
;
page
;
Table:
addwf PCL,f ; Jump to character
dt "This is a test line!" ; 20
Character string terminated with a 0
Table_End:
retlw 0
;
; Check to
ensure table doesn't cross a page boundary.
if ( (Table & 0x0FF) >=
(Table_End & 0x0FF) )
MESSG
"Warning - User Definded: Table crosses page boundry in computed
jump"
endif
;
;*******************************************************************
;* The LCD
Module Subroutines *
;*******************************************************************
;
;*******************************************************************
;*SendChar
- Sends character to LCD *
;*This
routine splits the character into the upper and lower *
;*nibbles
and sends them to the LCD, upper nibble first. *
;*******************************************************************
;
Send_Char
movwf Char ; Character to be sent is in W
call Wait_Busy ; Wait for LCD to be ready
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movf Char,w
andlw 0xF0 ; Get upper nibble
iorwf LCD_DATA,F ; Send data to LCD
bcf LCD_CNTL, R_W ; Set LCD to write
bsf LCD_CNTL, RS ; Set LCD to data mode
bsf LCD_CNTL, E ; toggle E for LCD
bcf LCD_CNTL, E
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
swapf Char,W
andlw 0xF0 ; Get lower nibble
iorwf LCD_DATA,F ; Send data to LCD
bsf LCD_CNTL, E ; toggle E for LCD
bcf LCD_CNTL, E
return
;
page
;
;*******************************************************************
;* Send_Cmd
- Sends command to LCD *
;* This
routine splits the command into the upper and lower *
;* nibbles
and sends them to the LCD, upper nibble first. *
;*******************************************************************
Send_Cmd
movwf Char ; Character to be sent is in W
call Wait_Busy ; Wait for LCD to be ready
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movf Char,w
andlw 0xF0 ; Get upper nibble
iorwf LCD_DATA,F ; Send data to LCD
bcf LCD_CNTL,R_W ; Set LCD to write
bcf LCD_CNTL,RS ; Set LCD to command mode
bsf LCD_CNTL,E ; toggle E for LCD
bcf LCD_CNTL,E
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
swapf Char,W
andlw 0xF0 ; Get lower nibble
iorwf LCD_DATA,F ; Send data to LCD
bsf LCD_CNTL,E
; toggle E for LCD
bcf LCD_CNTL,E
return
;
page
;
;*******************************************************************
;* This
routine checks the busy flag, returns when not busy *
;* Affects: *
;* Temp - Returned with busy/address *
;*******************************************************************
;
Wait_Busy
bsf STATUS, RP0 ; Select Register page 1
movlw 0xf0 ; Set port to input
iorwf LCD_DATA_TRIS,W ; Only set upper half of
port
movwf LCD_DATA_TRIS
bcf STATUS, RP0 ; Select Register page 0
bcf LCD_CNTL, RS ; Set LCD for Command mode
bsf LCD_CNTL, R_W ; Setup to read busy flag
bsf LCD_CNTL, E ; Set E high
bcf LCD_CNTL, E ; Set E low
movf LCD_DATA, W ; Read upper nibble busy flag, DDRam
address
andlw 0xF0 ; Mask out lower nibble
movwf Temp
bsf LCD_CNTL, E ; Toggle E to get lower nibble
bcf LCD_CNTL, E
swapf LCD_DATA, w ; Read lower nibble busy flag, DDRam
address
andlw 0x0F ; Mask out upper nibble
iorwf Temp,W ; Combine nibbles
btfsc Temp, 7 ; Check busy flag, high = busy
goto Wait_Busy ; If busy, check again
bcf LCD_CNTL, R_W
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
bcf STATUS, RP0 ; Select Register page 0
return
;
page
;
;*******************************************************************
;* This
routine checks the busy flag, returns ff if busy 00 if not *
;*
busy. Temp will contain the current
address. *
;*
*
;* Affects:
*
;* Temp - Returned with busy/address *
;*******************************************************************
;
Check_Busy
bsf STATUS, RP0 ; Select Register page 1
movlw 0xf0 ; Set port to input
iorwf LCD_DATA_TRIS,W ; Only set upper half of
port
movwf LCD_DATA_TRIS
bcf STATUS, RP0 ; Select Register page 0
bcf LCD_CNTL, RS ; Set LCD for Command mode
bsf LCD_CNTL, R_W ; Setup to read busy flag
bsf LCD_CNTL, E ; Set E high
bcf LCD_CNTL, E ; Set E low
movf LCD_DATA, W ; Read upper nibble busy flag, DDRam
address
andlw 0xF0
; Mask out lower nibble
movwf Temp
bsf LCD_CNTL, E ; Toggle E to get lower nibble
bcf LCD_CNTL, E
swapf LCD_DATA, w ; Read lower nibble busy flag, DDRam
address
andlw 0x0F ; Mask out upper nibble
iorwf Temp,W ; Combine nibbles
btfsc Temp, 7 ; Check busy flag, high = busy
goto Busy_Exit ; If busy exit with busy flag set
bcf LCD_CNTL, R_W
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
bcf STATUS, RP0 ; Select Register page 0
retlw 0x00
Busy_Exit:
bcf LCD_CNTL, R_W
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
bcf STATUS, RP0 ; Select Register page 0
retlw 0xff
;
page
;
; Initilize
the LCD Display Module
;
LCD_Init:
bcf LCD_CNTL, E ; Clear all controll lines
bcf LCD_CNTL, RS
bcf LCD_CNTL, R_W
call Delay15000 ; Wait for 15ms for LCD to get powered up
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movlw 0x030 ; Command for 4-bit interface high
nibble
iorwf LCD_DATA,F ; Send data to LCD
bsf STATUS, RP0 ; Select Register page 1
movlw 0x0F
andwf LCD_DATA_TRIS,W
movwf LCD_DATA_TRIS ; Set Port for output
BCF STATUS, RP0 ; Select Register page 0
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
call Delay4100 ; Delay for at least 4.1ms before
continuing
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
call Delay100 ; delay for at least 100usec before
continuing
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
call Wait_Busy ; From here on, the Busy Bit will be
valid.
movlw 0x0f
andwf LCD_DATA,F ; Clear the upper nibble
movlw 0x020 ; Command for 4-bit interface high
nibble (Really an 8bit command but
; lower 4 bits are don't care at this point)
iorwf LCD_DATA,F ; Send data to LCD
bsf LCD_CNTL, E ; Clock the initalize command to LCD
module
bcf LCD_CNTL, E
movlw FUNCTION_SET ; Send the function set command 4-bit I/F,
Font, Number of lines
call Send_Cmd ; Can now use the Send_Cmd routine
since Busy Bit Valid and in 4bit mode.
movlw DISP_OFF
call Send_Cmd
movlw DISP_ON
call Send_Cmd
movlw ENTRY_INC
call Send_Cmd
; LCD
Module is now initalized
return
;
; Delay
routines. These routines need to be
modified to work with the particular PIC configuration
;
used. For test purposes, they are
instruction count delays based on 4Mhz PIC.
The delays are a
; little
longer than advertised but close enough for testing.
;
Delay4100:
movlw d'252'
movwf r1
movlw 4
movwf r2
movlw 1
movwf r3
movlw 1
movwf r4
delay_loop:
nop
decfsz r1,f
goto delay_loop
decfsz r2,f
goto delay_loop
decfsz r3,f
goto delay_loop
decfsz r4,f
goto delay_loop
return
Delay100:
movlw d'22'
movwf r1
movlw 1
movwf r2
movlw 1
movwf r3
movlw 1
movwf r4
goto delay_loop
Delay15000:
movlw d'156'
movwf r1
movlw 15
movwf r2
movlw 1
movwf r3
movlw 1
movwf r4
goto delay_loop
end
|
:
//
CBuild/
JavaScript 1.2-5.6/
Delphi6/
I2C /
AVR /
/
AHDL/
VHDL/
LPT EPP/ LPT ECP/ PCI/ COM port/ I2C/ RS-232/
Используются технологии uCoz
|
