2 field definitions, 1 defining a field at a specific offset, Field definitions – Teledyne LeCroy Voyager Exerciser Generation Script Language Manual User Manual
Page 41: Defining a field at a specific offset, Fields_d
Teledyne LeCroy
Voyager USB 3.0 Exerciser Generation Script Language Reference Manual
32
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 and when sending a packet. See
Changing Structure Parser Variables
Send Packet Instruction
for more information.
8.2.1 Defining a Field at a Specific Offset
If the offset parameter is in a field definition, the field is bound to a specific offset.
Examples
const
F3_OFFSET =
16
const
F3_LEN =
8
# Declare the packet template 'SomeTemplate'.
Packet
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.
}