class Blaster:
def __init__(self, debug=False):
self.blaster = Ftdi()
self.virtual = True
self.blaster.LATENCY_MIN = 1
self.blaster.open(0x09FB, 0x6001)
self.blaster.write_data_set_chunksize(1)
self._last = None # Last deferred TDO bit
self.debug = debug
def readwritebit(self, tms, tdi):
val = ENA + tms * TMS + tdi * TDI
self.blaster._write(bytes([val]))
val = ENA + tms * TMS + tdi * TDI + TCK + TDO
self.blaster._write(bytes([val]))
rd = self.blaster.read_data_bytes(1, attempt=3)
tdo = ord(rd) & 1
return tdo
def writebit(self, tms, tdi):
val = ENA + tms * TMS + tdi * TDI
self.blaster._write(bytes([val]))
val = ENA + tms * TMS + tdi * TDI + TCK
self.blaster._write(bytes([val]))
def shiftinoutval(self, length, val):
outval = 0
if (self.debug):
print(">>Out{2:d}:0x{0:x}={0:0{1}b}".format(val, length, length))
nbytes = length >> 3
if nbytes > 63:
raise Exception("length > 63 bytes")
self.blaster._write(bytes([ENA]))
valcmd = bytearray([BYTESHIFT | DORDWR | (nbytes & 0x3F)])
txlen = (nbytes & 0x3F) << 3
valbytes = (val & ((1 << txlen) - 1)).to_bytes(nbytes & 0x3F, 'little')
valcmd.extend(valbytes)
self.blaster._write(valcmd)
rd = self.blaster.read_data_bytes(nbytes & 0x3F, attempt=3)
rxlen = len(rd)
outval += int.from_bytes(rd, 'little')
val >>= txlen
if (self.debug):
print(">>Inbytes{2:d}:0x{0:x}={0:0{1}b}".format(
outval, rxlen * 8, rxlen))
length -= txlen
for i in range(length):
bit = val & 1
tdo = self.readwritebit(0, bit)
val >>= 1
outval += (tdo << (i + rxlen * 8))
if (self.debug):
print(">>In{2:d}:0x{0:x}={0:0{1}b}".format(outval,
(length + nbytes * 8),
length))
return outval
def shiftinval(self, length, val):
if (self.debug):
print(">>Out{2:d}:0x{0:x}={0:0{1}b}".format(val, length, length))
nbytes = length >> 3
while nbytes > 0:
self.blaster._write(bytes([ENA]))
valcmd = bytearray([BYTESHIFT | (nbytes & 0x3F)])
len = (nbytes & 0x3F) << 3
valbytes = (val & ((1 << len) - 1)).to_bytes(
nbytes & 0x3F, 'little')
valcmd.extend(valbytes)
self.blaster._write(valcmd)
val >>= len
nbytes -= nbytes & 0x3F
length -= len
for i in range(length):
bit = val & 1
tdo = self.writebit(0, bit)
val >>= 1
def write_tms(self, tms, should_read=False):
"""Change the TAP controller state"""
if not isinstance(tms, BitSequence):
raise JtagError('Expect a BitSequence')
tdo = 0
for val in tms:
if (self._last is not None):
if (should_read):
if (self.debug):
print(">>Tmsout:" + bin(self._last))
tdo = self.readwritebit(val, int(self._last))
if (self.debug):
print(">>Tmsin:" + bin(tdo))
else:
if (self.debug):
print(">>Tmsout:" + bin(self._last))
self.writebit(val, int(self._last))
else:
self.writebit(val, 0)
should_read = False
self._last = None
return BitSequence(tdo, 1)
def reset(self):
"""Reset the attached TAP controller.
sync sends the command immediately (no caching)
"""
# we can either send a TRST HW signal or perform 5 cycles with TMS=1
# to move the remote TAP controller back to 'test_logic_reset'state
# TAP reset (even with HW reset, could be removed though)
self.write_tms(BitSequence('11111'))
def write(self, out, use_last=True):
if not isinstance(out, BitSequence):
return JtagError('Expect a BitSequence')
if use_last:
(out, self._last) = (out[:-1], bool(out[-1]))
length = len(out)
self.shiftinval(length, int(out))
def writeread(self, out, use_last=True):
if not isinstance(out, BitSequence):
return JtagError('Expect a BitSequence')
if use_last:
(out, self._last) = (out[:-1], bool(out[-1]))
length = len(out)
bs = BitSequence(value=self.shiftinoutval(length, int(out)),
length=length)
return bs
def read(self, length):
"""Read out a sequence of bits from TDO"""
bs = BitSequence(value=self.shiftinoutval(length, 0), length=length)
return bs
def close(self):
self.blaster.close()
