Informs the compiler about the used libraries.
$LIB "libname1" [, "libname2"]
Libname1 is the name of the library that holds ASM routines that are used by your program. More filenames can be specified by separating the names by a comma.
The specified libraries will be searched when you specify the routines to use with the $EXTERNAL directive.
The search order is the same as the order you specify the library names.
The MCS.LBX will be searched last and is always included so you don't need to specify it with the $LIB directive.
Because the MCS.LBX is searched last you can include duplicate routines in your own library. These routines will be used instead of the ones from the default MCS.LBX library. This is a good way when you want to enhance the MCS.LBX routines. Just copy the MCS.LIB to a new file and make the changes in this new file. When we make changes to the library your changes will be preserved.
Creating your own LIB file
A library file is a simple ASCII file. It can be created with the BASCOM editor, notepad or any other ASCII editor.
When you use BASCOM, make sure that the LIB extension is added to the Options, Environment, Editor, "No reformat extension".
This will prevent the editor to reformat the LIB file when you open it.
The file must include the following header information. It is not used yet but will be later.
copyright = Your name
www = optional location where people can find the latest source
email = your email address
comment = AVR compiler library
libversion = the version of the library in the format : 1.00
date = date of last modification
statement = A statement with copyright and usage information
The routine must start with the name in brackets and must end with the [END].
The following ASM routine example is from the MYLIB.LIB library.
ldd r26,y+2 ; load address of X
ld r24,x ; get value into r24
Inc r24 ; value + 1
St x,r24 ; put back
ldd r26,y+0 ; address of Y
st x,r24 ; store
ret ; ready
After you have saved your library in the LIB subdirectory you must compile it with the LIB Manager. Or you can include it with the LIB extension in which case you don’t have to compile it.
About the assembler.
When you reference constants that are declared in your basic program you need to put a star(*) before the line.
' Basic Program
CONST myconst = 7
' asm lib
* sbi portb, myconst
By adding the *, the line will be compiled when the basic program is compiled. It will not be changed into object code in the LBX file.
When you use constants you need to use valid BASIC constants:
Ldi r24, 1+1
Ldi r24, &B001 ; binary basic
Ldi r24,0b001 ; binary
Ldi r24,&HFF ; hex basic
Ldi r24,$FF ; hex
Ldi r24,0xFF ; hex
Other syntax is NOT supported.
$regfile = "m48def.dat"
$crystal = 4000000
$baud = 19200
Config Com1 = Dummy , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0
'In order to let this work you must put the mylib.lib file in the LIB dir
'And compile it to a LBX
'define the used library
'you can also use the original ASM :
'also define the used routines
'this is needed so the parameters will be placed correct on the stack
Declare Sub Test(byval X Asbyte , Y Asbyte)
'reserve some space
Dim Z As Byte
'call our own sub routine
Call Test(1 , Z)
'z will be 2 in the used example