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Improved doc string of signed() function

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This commit is contained in:
Guenter Dannoritzer 2008-08-05 22:39:51 +02:00
parent 6c5094d280
commit eb009e879e
1 changed files with 7 additions and 4 deletions
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11
myhdl/_intbv.py
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@ -444,9 +444,10 @@ class intbv(object):
The intbv.signed() function will classify the value of the intbv The intbv.signed() function will classify the value of the intbv
instance either as signed or unsigned. If the value is classified instance either as signed or unsigned. If the value is classified
as signed it will be returned unchanged as integer value. If the as signed it will be returned unchanged as integer value. If the
value is considered unsigned, the value will be returned as value is considered unsigned, the bits as specified by _nrbits
integer value, with the sign being considered by the msb. The msb will be considered as 2's complement number and returned. This
is the msb as specified by _nrbits. feature will allow to create slices and have the sliced bits be
considered a 2's complement number.
The classification is based on the following possible combinations The classification is based on the following possible combinations
of the min and max value. of the min and max value.
@ -470,12 +471,14 @@ class intbv(object):
based on the _nrbits value. based on the _nrbits value.
So the test will be if min >= 0 and _nrbits > 0. Then the instance So the test will be if min >= 0 and _nrbits > 0. Then the instance
is considered unsigned and the value is change based on the msb. is considered unsigned and the value is returned as 2's complement
number.
''' '''
# value is considered unsigned # value is considered unsigned
if self.min >= 0 and self._nrbits > 0: if self.min >= 0 and self._nrbits > 0:
# get 2's complement value of bits
msb = self._nrbits-1 msb = self._nrbits-1
sign = ((self._val >> msb) & 0x1) > 0 sign = ((self._val >> msb) & 0x1) > 0