def _to_pack(self):
'''Produces a tuple ready to be packed with pack_val() according to its
internal value
'''
if not self.get_trans():
# expand uint28 value to uint32 format
dec = decompose_uint(1<<7, self.get_val())
if len(dec) < 4:
dec.extend( [0]*(4-len(dec)) )
exp = reduce(lambda x,y: (x<<8)+y, reversed(dec))
return [(TYPE_UINT, exp, self.get_bl())]
else:
return []
def _from_char(self, char):
'''Consume the charpy intance and set its internal value according to
it
'''
if not self.get_trans():
try:
exp = char.get_uint(32)
except CharpyErr as err:
raise(CharpyErr('{0} [_from_char]: {1}'.format(self._name, err)))
else:
# get uint32 value, zero all 8'th bit of each byte
# and pack it to an uint28 value
dec = decompose_uint(1<<8, exp)
if len(dec) < 4:
dec.extend( [0]*(4-len(dec)) )
val = reduce(lambda x,y: ((x&0x7f)<<7)+(y&0x7f), reversed(dec))
try:
self.set_val(val)
except Exception as err:
raise(EltErr('{0} [_from_char]: {1}'\
.format(self._name, err)))
