Menu
Recent Articles
PicŪ Basic
The example below will Dim a large String and then place new data into it. A temp string is loaded with the Text and a converted variable tagged onto the end. This temp string is then inserted into the main string; the whole process is then repeated 10 times.
Lastly these 10 sections are read back and displayed on the terminal
This file will run in ISIS on the PIC18_ALCD_VHB board
As usual include the file "String_Array_InOut.inc" at the start of your code, then use as required.
'
' Two macros that simulate a String array load and retrieve
' The macros use NO variable RAM other that SFR registers, and use no Call Stack space.
'
' For 18F devices only. Using Proton+ Version 3.03 Onwards.
'
' This program can be tested using the PIC18_ALCD_VHB file in the ISIS simulator.
'
Include "Proton18_4.inc" ' Use the Proton Dev board for the demonstration
Dim Index1 As Byte ' Temporary byte used for demo loop
Dim TempString As String * 10 ' Temporary string used by demo loop
'
' Create a string large enough for all the characters
'
' The values shown below will create an array of 10 strings each holding 10 characters
Symbol Dimension_1 = 10 ' Ten Strings in the array
Symbol Dimension_2 = 10 ' Each holding 10 characters
Reminders = OFF
Warnings = OFF
Dim String1 As String * (Dimension_1 * Dimension_2) ' Create a string large enough to hold all the characters
Warnings = On
Symbol String1_Length = 10 ' Holds the length of each string within the array
'--------------------------------------------------------------------------------------
' Simulate a String array String1[Index1] = CHARS_IN
' The algorithm for accessing the elements is: -
' FSR0 = String_Name
' PROD = Index1 * String_Length
' FSR0 = FSR0 + PROD
' Syntax: -
' Str_Array_Out String_Name , String_Length , [Index1] , CharactersIn
' Where: -
' String_Name is the name of the string array in question
' String_Length is the individual string lengths within the array
' Index1 is the index value of the string array
' CharactersIn is the characters to place into the array
Str_Array_Out Macro- String_Name, String_Length, Index_1, CharactersIn
#if(PRM_COUNT != 4) ; Ensure the correct amount of parameters
#error "Incorrect amount of parameters for Str_Array_Out macro. 4 Parameters required"
ExitM
#endif
#if(PRM_1 != String) ; Ensure the first parameter is a string
#error "Parameter 1 must be a String for Str_Array_Out macro"
ExitM
#endif
Asm-
#if((PRM_3 == NUM8) || (PRM_3 == NUM16) || (PRM_3 == NUM32))
movlw Index_1
#endif
#if((PRM_3 == Byte) || (PRM_3 == Word) || (PRM_3 == DWord))
#if(Index_1 <= BANKA_END)
movf Index_1,w
#else
movff Index_1,WREG
#endif
#endif
EndAsm-
#if((PRM_2 != NUM8) && (PRM_2 != NUM16) && (PRM_2 != NUM32))
#error "String LENGTH must be an unsigned constant value for Str_Array_Out macro"
#endif
Asm-
lfsr 0,String_Name ; Point FSR0L/H to the address of the string array
mullw String_Length ; \
movf PRODL,W ; |
addwf FSR0L,F ; Calculate position of string array within main String
movf PRODH,W ; |
addwfc FSR0H,F ; /
;
; FSR0 is now pointing to the correct string within the array based on Index_1 and String_Length
;
#if((PRM_4 == CHAR) || (PRM_4 == LABEL)) ; Is the parameter a quoted string of characters or a label?
movlw Low CharactersIn ; \
movwf TBLPTRL ; Point TBLPTRL/H to the code memory holding the string of characters
movlw High CharactersIn ; |
movwf TBLPTRH ; /
clrf EECON1 ; \
bsf EECON1,EEPGD ; / Setup for read from code memory
movlw String_Length ; Create loop for all characters in string array part
tblrd*+ ; Read then increment code memory pointer
movf TABLAT,F ; \
bz $ + 10 ; / Exit if a NULL found
movff TABLAT,POSTINC0 ; Place the character from code memory to RAM
decfsz WREG,F ; Next character
bra $ - 12 ; Until all characters transfered
#endif
#if(PRM_4 == String) ; Is the parameter another string ?
lfsr 1,CharactersIn ; Point FSR1L/H to the address of the source string
movlw String_Length ; Create loop for all characters in string array part
movf INDF1,F ; \
bz $ + 10 ; / Exit if a NULL found
movff POSTINC1,POSTINC0 ; Place the character from source string to dest string
decfsz WREG,F ; Next character
bra $ - 10 ; Until all characters transfered
#endif
#if((PRM_4 == Word) || (PRM_4 == DWord))
movff CharactersIn,FSR0L ; \
movff CharactersIn + 1,FSR0H ; / Point FSR1L/H to the address of the source string
movlw String_Length ; Create a loop for all the characters in the string array part
movf INDF1,F ; \
bz $ + 10 ; / Exit if a NULL found
movff POSTINC1,POSTINC0 ; Place the character from source string to dest string
decfsz WREG,F ; Next character
bra $ - 10 ; Until all characters transfered
#endif
#if((PRM_4 == NUM8) || (PRM_4 == NUM16) || (PRM_4 == NUM32))
#if(CharactersIn == 0)
clrf INDF0
#else
#if(CharactersIn == 255)
setf INDF0
#else
movlw CharactersIn
movwf INDF0
#endif
#endif
#endif
#if(PRM_4 == Byte)
movff CharactersIn,INDF0
#endif
EndAsm-
EndM
'--------------------------------------------------------------------------------------
' Simulate a String array Dest_String = Source_String [Index1]
' The algorithm for accessing the elements is: -
' FSR0 = String_Name
' PROD = Index1 * String_Length
' FSR0 = FSR0 + PROD
' Syntax:
' Dest_String = Str_Array_In String_Name , String_Length , [Index1]
' Where: -
' Dest_String is the destination string to hold the string extracted from the array
' ARRAY_NAME is the name of the array in question
' String_Length is the individual string lengths within the array
' Index1 is the index value of the string array
Str_Array_In Macro- String_Name, String_Length, Index_1
#if(PRM_COUNT != 3)
#error "Incorrect amount of parameters for Str_Array_In macro. 3 Parameters required"
ExitM
#endif
#if(PRM_1 != String)
#error "Parameter 1 must be a String for Str_Array_In macro"
ExitM
#endif
Asm-
#if((PRM_3 == NUM8) || (PRM_3 == NUM16) || (PRM_3 == NUM32))
movlw Index_1
#endif
#if((PRM_3 == Byte) || (PRM_3 == Word) || (PRM_3 == DWord))
#if(Index_1 <= BANKA_END)
movf Index_1,w
#else
movff Index_1,WREG
#endif
#endif
EndAsm-
#if((PRM_2 != NUM8) && (PRM_2 != NUM16) && (PRM_2 != NUM32))
#error "String LENGTH must be an unsigned constant value for Str_Array_In macro"
#endif
Asm-
lfsr 1,String_Name ; Point FSR1L/H to the address of the string array
mullw String_Length ; \
movf PRODL,W ; |
addwf FSR1L,F ; Calculate position of string array within main String
movf PRODH,W ; |
addwfc FSR1H,F ; /
; FSR1 is now pointing to the correct string within the array based on Index_1 and String_Length
EndAsm-
EndM
'
'-------------------------------------------------------------------
' The Main Program Loop Starts Here
' Test the macros by loading then retrieving values
DelayMS 100 ' Wait for things to stabilise
Clear ' Clear all RAM before we start
HSerOut ["LOADING STRING ARRAY",13,13]
For Index1 = 0 To Dimension_1 - 1 ' Create a loop for all the strings within the array
TempString = "String " + Str$(DEC2 Index1)' Load a string with characters
Str_Array_Out String1,String1_Length,[Index1], TempString ' Place the string into the string array
HSerOut [TempString,13] ' Display the string loaded into the array
Next
DelayMS 600 ' Pause for drama
HSerOut ["--------------------",13,13]
HSerOut ["READING STRING ARRAY",13,13]
For Index1 = 0 To Dimension_1 - 1 ' Create a loop for all the strings within the array
TempString = Str_Array_In String1,String1_Length,[Index1] ' Retreive a string from the string array
HSerOut [TempString,13] ' Display the results serially
Next
Stop
' Two macros that simulate a String array load and retrieve
' The macros use NO variable RAM other that SFR registers, and use no Call Stack space.
'
' For 18F devices only. Using Proton+ Version 3.03 Onwards.
'
' This program can be tested using the PIC18_ALCD_VHB file in the ISIS simulator.
'
Include "Proton18_4.inc" ' Use the Proton Dev board for the demonstration
Dim Index1 As Byte ' Temporary byte used for demo loop
Dim TempString As String * 10 ' Temporary string used by demo loop
'
' Create a string large enough for all the characters
'
' The values shown below will create an array of 10 strings each holding 10 characters
Symbol Dimension_1 = 10 ' Ten Strings in the array
Symbol Dimension_2 = 10 ' Each holding 10 characters
Reminders = OFF
Warnings = OFF
Dim String1 As String * (Dimension_1 * Dimension_2) ' Create a string large enough to hold all the characters
Warnings = On
Symbol String1_Length = 10 ' Holds the length of each string within the array
'--------------------------------------------------------------------------------------
' Simulate a String array String1[Index1] = CHARS_IN
' The algorithm for accessing the elements is: -
' FSR0 = String_Name
' PROD = Index1 * String_Length
' FSR0 = FSR0 + PROD
' Syntax: -
' Str_Array_Out String_Name , String_Length , [Index1] , CharactersIn
' Where: -
' String_Name is the name of the string array in question
' String_Length is the individual string lengths within the array
' Index1 is the index value of the string array
' CharactersIn is the characters to place into the array
Str_Array_Out Macro- String_Name, String_Length, Index_1, CharactersIn
#if(PRM_COUNT != 4) ; Ensure the correct amount of parameters
#error "Incorrect amount of parameters for Str_Array_Out macro. 4 Parameters required"
ExitM
#endif
#if(PRM_1 != String) ; Ensure the first parameter is a string
#error "Parameter 1 must be a String for Str_Array_Out macro"
ExitM
#endif
Asm-
#if((PRM_3 == NUM8) || (PRM_3 == NUM16) || (PRM_3 == NUM32))
movlw Index_1
#endif
#if((PRM_3 == Byte) || (PRM_3 == Word) || (PRM_3 == DWord))
#if(Index_1 <= BANKA_END)
movf Index_1,w
#else
movff Index_1,WREG
#endif
#endif
EndAsm-
#if((PRM_2 != NUM8) && (PRM_2 != NUM16) && (PRM_2 != NUM32))
#error "String LENGTH must be an unsigned constant value for Str_Array_Out macro"
#endif
Asm-
lfsr 0,String_Name ; Point FSR0L/H to the address of the string array
mullw String_Length ; \
movf PRODL,W ; |
addwf FSR0L,F ; Calculate position of string array within main String
movf PRODH,W ; |
addwfc FSR0H,F ; /
;
; FSR0 is now pointing to the correct string within the array based on Index_1 and String_Length
;
#if((PRM_4 == CHAR) || (PRM_4 == LABEL)) ; Is the parameter a quoted string of characters or a label?
movlw Low CharactersIn ; \
movwf TBLPTRL ; Point TBLPTRL/H to the code memory holding the string of characters
movlw High CharactersIn ; |
movwf TBLPTRH ; /
clrf EECON1 ; \
bsf EECON1,EEPGD ; / Setup for read from code memory
movlw String_Length ; Create loop for all characters in string array part
tblrd*+ ; Read then increment code memory pointer
movf TABLAT,F ; \
bz $ + 10 ; / Exit if a NULL found
movff TABLAT,POSTINC0 ; Place the character from code memory to RAM
decfsz WREG,F ; Next character
bra $ - 12 ; Until all characters transfered
#endif
#if(PRM_4 == String) ; Is the parameter another string ?
lfsr 1,CharactersIn ; Point FSR1L/H to the address of the source string
movlw String_Length ; Create loop for all characters in string array part
movf INDF1,F ; \
bz $ + 10 ; / Exit if a NULL found
movff POSTINC1,POSTINC0 ; Place the character from source string to dest string
decfsz WREG,F ; Next character
bra $ - 10 ; Until all characters transfered
#endif
#if((PRM_4 == Word) || (PRM_4 == DWord))
movff CharactersIn,FSR0L ; \
movff CharactersIn + 1,FSR0H ; / Point FSR1L/H to the address of the source string
movlw String_Length ; Create a loop for all the characters in the string array part
movf INDF1,F ; \
bz $ + 10 ; / Exit if a NULL found
movff POSTINC1,POSTINC0 ; Place the character from source string to dest string
decfsz WREG,F ; Next character
bra $ - 10 ; Until all characters transfered
#endif
#if((PRM_4 == NUM8) || (PRM_4 == NUM16) || (PRM_4 == NUM32))
#if(CharactersIn == 0)
clrf INDF0
#else
#if(CharactersIn == 255)
setf INDF0
#else
movlw CharactersIn
movwf INDF0
#endif
#endif
#endif
#if(PRM_4 == Byte)
movff CharactersIn,INDF0
#endif
EndAsm-
EndM
'--------------------------------------------------------------------------------------
' Simulate a String array Dest_String = Source_String [Index1]
' The algorithm for accessing the elements is: -
' FSR0 = String_Name
' PROD = Index1 * String_Length
' FSR0 = FSR0 + PROD
' Syntax:
' Dest_String = Str_Array_In String_Name , String_Length , [Index1]
' Where: -
' Dest_String is the destination string to hold the string extracted from the array
' ARRAY_NAME is the name of the array in question
' String_Length is the individual string lengths within the array
' Index1 is the index value of the string array
Str_Array_In Macro- String_Name, String_Length, Index_1
#if(PRM_COUNT != 3)
#error "Incorrect amount of parameters for Str_Array_In macro. 3 Parameters required"
ExitM
#endif
#if(PRM_1 != String)
#error "Parameter 1 must be a String for Str_Array_In macro"
ExitM
#endif
Asm-
#if((PRM_3 == NUM8) || (PRM_3 == NUM16) || (PRM_3 == NUM32))
movlw Index_1
#endif
#if((PRM_3 == Byte) || (PRM_3 == Word) || (PRM_3 == DWord))
#if(Index_1 <= BANKA_END)
movf Index_1,w
#else
movff Index_1,WREG
#endif
#endif
EndAsm-
#if((PRM_2 != NUM8) && (PRM_2 != NUM16) && (PRM_2 != NUM32))
#error "String LENGTH must be an unsigned constant value for Str_Array_In macro"
#endif
Asm-
lfsr 1,String_Name ; Point FSR1L/H to the address of the string array
mullw String_Length ; \
movf PRODL,W ; |
addwf FSR1L,F ; Calculate position of string array within main String
movf PRODH,W ; |
addwfc FSR1H,F ; /
; FSR1 is now pointing to the correct string within the array based on Index_1 and String_Length
EndAsm-
EndM
'
'-------------------------------------------------------------------
' The Main Program Loop Starts Here
' Test the macros by loading then retrieving values
DelayMS 100 ' Wait for things to stabilise
Clear ' Clear all RAM before we start
HSerOut ["LOADING STRING ARRAY",13,13]
For Index1 = 0 To Dimension_1 - 1 ' Create a loop for all the strings within the array
TempString = "String " + Str$(DEC2 Index1)' Load a string with characters
Str_Array_Out String1,String1_Length,[Index1], TempString ' Place the string into the string array
HSerOut [TempString,13] ' Display the string loaded into the array
Next
DelayMS 600 ' Pause for drama
HSerOut ["--------------------",13,13]
HSerOut ["READING STRING ARRAY",13,13]
For Index1 = 0 To Dimension_1 - 1 ' Create a loop for all the strings within the array
TempString = Str_Array_In String1,String1_Length,[Index1] ' Retreive a string from the string array
HSerOut [TempString,13] ' Display the results serially
Next
Stop
Using PDS with SPI GLCD based on ST7565R Controller
Graphic LCDs based on the ST7565 are cheaper then GLCDs with other controllers. SPI requires only four pins. If the circuit