© MCS Electronics, 1995-2007
A LOCAL variable is a temporary variable that is stored on the frame.
When the SUB or FUNCTION is terminated, the memory will be released back to the frame. BIT variables are not possible because they are GLOBAL to the system.
The AT , ERAM, SRAM, XRAM directives can not be used with a local DIM statement. Also local arrays are not possible.
See also
DIM
ASM
NONE
Example
'----------------------------------------------------------------------------- |
|
------------ |
: declare.bas |
'name |
'copyright |
: (c) 1995-2005, MCS Electronics |
'purpose |
: demonstrate using declare |
'micro |
: Mega48 |
'suited for demo |
: yes |
'commercial addon needed |
: no |
' Note that the usage of SUBS works different in BASCOM-8051 |
'----------------------------------------------------------------------------- |
|
------------ |
|
$regfile = "m48def.dat" |
' specify the used |
micro |
' used crystal |
$crystal = 4000000 |
frequency |
' use baud rate |
$baud = 19200 |
$hwstack = 32 |
' default use 32 |
for the hardware stack |
' default use 10 |
$swstack = 10 |
for the SW stack |
' default use 40 |
$framesize = 40 |
for the frame space |
|
' First the SUB programs must be declared
'Try a SUB without parameters
Declare Sub Test2
'SUB with variable that can not be changed(A) and
'a variable that can be changed(B1), by the sub program
'When BYVAL is specified, the value is passed to the subprogram
'When BYREF is specified or nothing is specified, the address is passed to 'the subprogram
Declare Sub Test(byval A As Byte , B1 As Byte) Declare Sub Testarray(byval A As Byte , B1 As Byte) 'All variable types that can be passed
'Notice that BIT variables can not be passed. 'BIT variables are GLOBAL to the application
Declare Sub Testvar(b As Byte , I As Integer , W As Word , L As Long , S As String)
page -559-
© MCS Electronics, 1995-2007
'passing string arrays needs a different syntax because the length of the strings must be passed by the compiler
'the empty () indicated that an array will be passed
Declare Sub Teststr(b As Byte , Dl() As String)
Dim Bb As Byte , I As Integer , W As Word , L As Long , S As String * 10
'dim used variables |
|
Dim Ar(10) As Byte |
'strng array |
Dim Sar(10) As String * 8 |
For Bb = 1 To 10 |
'fill the array |
Sar(bb) = Str(bb) |
Next |
|
Bb = 1
'now call the sub and notice that we always must pass the first address with index 1
Call Teststr(bb , Sar(1))
Call Test2 |
'call sub |
Test2 |
'or use without |
CALL
'Note that when calling a sub without the statement CALL, the enclosing
parentheses must be left out |
|
Bb = 1 |
'call sub with |
Call Test(1 , Bb) |
parameters |
'print value that |
Print Bb |
is changed |
|
'now test all the variable types |
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Call Testvar(bb , I , W , L , S ) |
|
Print Bb ; I ; W ; L ; S |
|
'now pass an array |
|
'note that it must be passed by reference |
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Testarray 2 , Ar(1) |
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Print "ar(1) = " ; Ar(1) |
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Print "ar(3) = " ; Ar(3) |
|
$notypecheck |
' turn off type |
checking |
|
Testvar Bb , I , I , I , S |
|
'you can turn off type checking when you want to pass a block of memory |
$typecheck |
'turn it back on |
End |
|
'End your code with the subprograms
'Note that the same variables and names must be used as the declared ones
Sub Test(byval A As Byte , B1 As Byte) |
'start sub |
Print A ; " " ; B1 |
'print passed |
variables |
'change value |
B1 = 3 |
'You can change A, but since a copy is passed to the SUB, |
'the change will not reflect to the calling variable |
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End Sub |
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Sub Test2 |
'sub without |
parameters |
|
Print "No parameters" |
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End Sub |
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© MCS Electronics, 1995-2007
Sub Testvar(b As Byte , I As Integer , W As Word , L As Long , S As String) Local X As Byte
X |
= |
5 |
'assign local |
B |
= |
X |
|
I |
= |
-1 |
|
W |
= |
40000 |
|
L |
= |
20000 |
|
S = "test" |
|
End Sub |
|
|
Sub Testarray(byval A As Byte , B1 As Byte) |
'start sub |
Print A ; " " ; B1 |
'print passed |
variables |
'change value of |
B1 = 3 |
element with index 1 |
'specify the index |
B1(1) = 3 |
which does the same as the line above |
'modify other |
B1(3) = 3 |
element of array |
|
'You can change A, but since a copy is passed to the SUB, 'the change will not reflect to the calling variable
End Sub
'notice the empty() to indicate that a string array is passed
Sub Teststr(b As Byte , Dl() As String) Dl(b) = Dl(b) + "add"
End Sub
LOCATE
Action
Moves the LCD cursor to the specified position.
Syntax
LOCATE y , x
Remarks
XConstant or variable with the position. (1-64*)
YConstant or variable with the line (1 - 4*)
*Depending on the used display
See also
CONFIG LCD , LCD , HOME , CLS
Partial Example
LCD "Hello"
Locate 1,10
LCD "*"
© MCS Electronics, 1995-2007
LOG
Action
Returns the natural logarithm of a single variable.
Syntax
Target = LOG(source)
Remarks
Target |
The single that is assigned with the LOG() of single target. |
Source |
The source single to get the LOG of. |
|
|
See also
EXP , LOG10
Example
Show sample
LOG10
Action
Returns the base 10 logarithm of a single variable.
Syntax
Target = LOG10(source)
Remarks
Target |
The single that is assigned with the base 10 logarithm of single target. |
Source |
The source single to get the base 10 LOG of. |
|
|
See also
EXP , LOG
Example
Show sample
LOOKDOWN
© MCS Electronics, 1995-2007
Action
Returns the index of a series of data.
Syntax
var = LOOKDOWN( value, label, entries)
Remarks
Var |
The returned index value |
Value |
The value to search for |
Label |
The label where the data starts |
entries |
The number of entries that must be searched |
|
|
When you want to look in BYTE series the VALUE variable must be dimensioned as a BYTE. When you want to look in INTEGER or WORD series the VALUE variable must be dimensioned as an INTEGER.
The LookDown function is the counterpart of the LookUp function.
Lookdown will search the data for a value and will return the index when the value is found. It will return –1 when the data is not found.
See also
LOOKUPSTR , LOOKUP
Example
'----------------------------------------------------------------------------- |
|
------------ |
: lookdown.bas |
'name |
'copyright |
: (c) 1995-2005, MCS Electronics |
'purpose |
: demo : LOOKDOWN |
'micro |
: Mega48 |
'suited for demo |
: yes |
'commercial addon needed |
: no |
'-----------------------------------------------------------------------------
------------
$regfile = "m48def.dat" |
' specify the used |
micro |
' used crystal |
$crystal = 4000000 |
frequency |
' use baud rate |
$baud = 19200 |
$hwstack = 32 |
' default use 32 |
for the hardware stack |
' default use 10 |
$swstack = 10 |
for the SW stack |
' default use 40 |
$framesize = 40 |
for the frame space |
|
Dim Idx As Integer , Search As Byte , Entries As Byte |
|
'we want to search for the value 3 |
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Search = 3 |
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'there are 5 entries in the table |
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Entries = 5 |
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