GPC allows you to manipulate the bits of a given variable. Bit operations are quite complicated, however, there is not really much call for them in the GPC environment and most users will never need them. Therefore, this section will assume you have an understanding of bits, bit masks, how they correlate with bytes and the binary system.
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Function
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Description
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Sets one bit
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Clears one bit
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Tests a bit
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Stores a value into a bit index
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Gets a value from a bit index
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 set_bit Sets one bit of a variable based on its bit index
Syntax
set_bit ( <variable> , <bit_index> );
Parameters
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<variable> :
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any defined variable
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<bit_index> :
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index point of the bit to be set, range 0~15
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 clear_bit Clears one bit of a variable based on its bit index
Syntax
clear_bit ( <variable> , <bit_index> );
Parameters
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<variable> :
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any defined variable
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<bit_index> :
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index point of the bit to be set, range 0~15
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 test_bit Tests a bit index point in a variable to check if it is TRUE or FALSE ( 1 or 0 )
Syntax
test_bit ( <variable> , <bit_index> );
Parameters
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<variable> :
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any defined variable
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<bit_index> :
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index point of the bit to be set, range 0~15
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Returns
TRUE is the bit is set, FALSE if it is not.
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 set_bits Stores a value in to a variable based on its bit index and a bit mask.
Syntax
set_bits ( <variable>, <value>, <bit_index>, <bit_mask> );
Parameters
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<variable> :
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any defined variable
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<value> :
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anything that has a value (constants, variables, functions, expressions, etc...)
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<bit_index> :
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index point of the bit to be set, range 0~15
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<bit_mask> :
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bit mask corresponding to the size, in bits, of the value to store (without shifting)
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 get_bits Extracts a balue from a variable based on a bit index and bit mask
Syntax
get_bits ( <variable>, <bit_index>, <bit_mask> );
Parameters
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<variable> :
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any defined variable
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<bit_index> :
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position of the less significant bit in the value to extract, range 0~15
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<bit_mask> :
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bit mask corresponding to the size, in bits, of the value to store (without shifting)
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Returns
An integer value.
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