Teledyne LeCroy UWBTrainer Exerciser Script Language - Manual (Page 95)

LeCroy Corporation UWBTrainer Exerciser - Generation Script Language Reference Manual
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10.11 Sizeof Operators
Several kinds of sizeof operators are currently supported:
• fld_size (field_name): Returns the length of the field in bits.
• pkt_size (template): Returns the length of the template payload in bits.
• pkt_size ($pkt_var_name): Returns the length of the structure variable payload in bits.
• pttn_size (data_pattern): Returns the length of the data pattern payload in bits.
Note: Fields that are not initialized with a variable length (declared as f : * ) have 0 length.
Examples
Main
{
# Examples of using 'sizeof' operators.
# Declare a 'structure' instance based on the template S1.
$S = S1
# Declare a 'structure' instance based on the template S2,
# changing the default value for the S16 field.
$W = S2 { S16 = 2 }
Send TX_FRAME
{
# Set the Len to the size of
# combined payload + the size of the 'Len' field .
Len = ( fld_size ( Len ) + pkt_size ( $S ) + pkt_size ( $W ) ) / 8
# Same as the previous assignment.
Len = ( fld_size ( Len ) + pkt_size ( S1 ) + pkt_size ( S2 ) ) / 8
# Data field contains combined payload of structures S and W.
Data = $S + $W
}
}