Teledyne LeCroy UWBTrainer Exerciser Script Language - Manual (Page 22)

LeCroy Corporation UWBTrainer Exerciser - Generation Script Language Reference Manual
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8.2 Field Definitions
You can define template fields using the following syntax:
Field_Name : [ offset, ] length [ (Byte Order attribute) ] [ = Field_Value ] [ [ list of possible values ] ]
or
Field_Name [ : length ] { Subfield definitions } [ (Byte Order attribute) [ = Field_Value ] [ [ list of
possible values ] ]
Note
1
: Specify all field offsets and lengths in bits. Numeric expressions with declared constants
are allowed in field offset and length definitions. All field and subfield names must be unique
inside a template.
Note
2
: You can define local fields for packet variable instances, register condition instructions,
and when sending a frame. See sections “Changing Structure Parser Variables” and
“Send Frame Instruction” for more information.
8.2.1 Defining a Field at a Specific Offset
If the offset parameter is in a field definition, then the field is bound to a specific offset.
Examples
const F3_OFFSET = 16
const F3_LEN = 8
# Declare the frame template 'SomeTemplate.
Frame SomeTemplate
{
F1 : 0 , 16 # Declare the 16-bit field 'F1' at offset 0.
F2 : 64 , 32 # Declare the 32-bit field 'F2' at offset 64.
F3 : F3_OFFSET, F3_LEN # Declare the 8-bit field 'F2' at offset 16.
F4 : F3_OFFSET + F3_LEN, 16 # Declare the 16-bit field 'F4' at
# offset 16+8.
}