Teledyne LeCroy LeCroy Analyzers File Based Decoding Manual User Manual
Page 47
File-based Decoding User Manual
Chapter 11: Primitives
LeCroy Corporation
41
GetNBits()
GetNBits (
Support
Supported by all LeCroy analyzers.
Return value
None.
Comments
Reads bit_count bits from bit_source starting at bit_offset. Returns null if
bit_offset
+ bit_count exceeds the number of bits in bit_source. If bit_count
is 32 or less, the result is returned as an integer. Otherwise, the result is 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 and PeekNBits. 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
integers that are interpreted as bytes.
bit_offset integer
Index of bit to start
reading from
bit_count integer
Number of bits to
read