Teledyne LeCroy Merlins Wand - Users Manual - Manual (Page 295)

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CATC M ERLIN ’ S W AND 2.00 C HAPTER D
User’s Manual CATC Scripting Language
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Field width specification is a positive integer that defines the field width, in
spaces, of the converted argument. If the number of characters in the argument is
smaller than the field width, then the field is padded with spaces. If the argument
has more characters than the field width has spaces, then the field will expand to
accommodate the argument.
GetNBits()
GetNBits (<bit_source list or raw>, <bit_offset
integer>, <bit_count integer>)
Return value
None.
Comments
Reads bit_count bits from bit_source starting at bit_offset.
Will return null if bit_offset + bit_count exceeds the number of
bits in bit_source. If bit_count is 32 or less, the result will be
returned as an integer. Otherwise, the result will be returned in a list format
that is the same as the input format. GetNBits also sets up the bit data
source and global bit offset used by NextNBits. Note that bits are indexed
starting at bit 0.
Example
raw = 'F0F0'; # 1111000011110000 binary
result = GetNBits ( raw, 2, 4 );
Trace ( "result = ", result );
The output would be
result = C # The result is given in hexadecimal. The
result in binary is 1100
In the call to GetNBits: starting at bit 2, reads 4 bits (1100) and returns
the value 0xC.
Parameter Meaning Default Value Comments
bit_source list, raw, or
integer
Can be an integer value (4 bytes) or a list of inte-
gers that are interpreted as bytes.
bit_offset integer Index of bit to
start reading
from
bit_count Number of
bits to read