## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
##
-# JTAG protocol decoder
-
import sigrokdecode as srd
+'''
+OUTPUT_PYTHON format:
+
+Packet:
+[<ptype>, <pdata>]
+
+<ptype>:
+ - 'NEW STATE': <pdata> is the new state of the JTAG state machine.
+ Valid values: 'TEST-LOGIC-RESET', 'RUN-TEST/IDLE', 'SELECT-DR-SCAN',
+ 'CAPTURE-DR', 'SHIFT-DR', 'EXIT1-DR', 'PAUSE-DR', 'EXIT2-DR', 'UPDATE-DR',
+ 'SELECT-IR-SCAN', 'CAPTURE-IR', 'SHIFT-IR', 'EXIT1-IR', 'PAUSE-IR',
+ 'EXIT2-IR', 'UPDATE-IR'.
+ - 'IR TDI': Bitstring that was clocked into the IR register.
+ - 'IR TDO': Bitstring that was clocked out of the IR register.
+ - 'DR TDI': Bitstring that was clocked into the DR register.
+ - 'DR TDO': Bitstring that was clocked out of the DR register.
+ - ...
+
+All bitstrings are a sequence of '1' and '0' characters. The right-most
+character in the bitstring is the LSB. Example: '01110001' (1 is LSB).
+'''
+
+jtag_states = [
+ # Intro "tree"
+ 'TEST-LOGIC-RESET', 'RUN-TEST/IDLE',
+ # DR "tree"
+ 'SELECT-DR-SCAN', 'CAPTURE-DR', 'UPDATE-DR', 'PAUSE-DR',
+ 'SHIFT-DR', 'EXIT1-DR', 'EXIT2-DR',
+ # IR "tree"
+ 'SELECT-IR-SCAN', 'CAPTURE-IR', 'UPDATE-IR', 'PAUSE-IR',
+ 'SHIFT-IR', 'EXIT1-IR', 'EXIT2-IR',
+]
+
class Decoder(srd.Decoder):
- api_version = 1
+ api_version = 2
id = 'jtag'
name = 'JTAG'
longname = 'Joint Test Action Group (IEEE 1149.1)'
license = 'gplv2+'
inputs = ['logic']
outputs = ['jtag']
- probes = [
+ channels = (
{'id': 'tdi', 'name': 'TDI', 'desc': 'Test data input'},
{'id': 'tdo', 'name': 'TDO', 'desc': 'Test data output'},
{'id': 'tck', 'name': 'TCK', 'desc': 'Test clock'},
{'id': 'tms', 'name': 'TMS', 'desc': 'Test mode select'},
- ]
- optional_probes = [
+ )
+ optional_channels = (
{'id': 'trst', 'name': 'TRST#', 'desc': 'Test reset'},
{'id': 'srst', 'name': 'SRST#', 'desc': 'System reset'},
{'id': 'rtck', 'name': 'RTCK', 'desc': 'Return clock signal'},
- ]
- options = {}
- annotations = [
- ['Text', 'Human-readable text'],
- ]
+ )
+ annotations = tuple([tuple([s.lower(), s]) for s in jtag_states])
def __init__(self, **kwargs):
# self.state = 'TEST-LOGIC-RESET'
self.bits_tdi = []
self.bits_tdo = []
self.samplenum = 0
+ self.ss_item = self.es_item = None
+ self.saved_item = None
+ self.first = True
def start(self):
- self.out_proto = self.register(srd.OUTPUT_PYTHON)
+ self.out_python = self.register(srd.OUTPUT_PYTHON)
self.out_ann = self.register(srd.OUTPUT_ANN)
def putx(self, data):
- self.put(self.samplenum, self.samplenum, self.out_ann, data)
+ self.put(self.ss_item, self.es_item, self.out_ann, data)
def putp(self, data):
- self.put(self.samplenum, self.samplenum, self.out_proto, data)
+ self.put(self.ss_item, self.es_item, self.out_python, data)
def advance_state_machine(self, tms):
self.oldstate = self.state
elif self.state == 'UPDATE-IR':
self.state = 'SELECT-DR-SCAN' if (tms) else 'RUN-TEST/IDLE'
- else:
- raise Exception('Invalid state: %s' % self.state)
-
def handle_rising_tck_edge(self, tdi, tdo, tck, tms):
# Rising TCK edges always advance the state machine.
self.advance_state_machine(tms)
- # Output the state we just switched to.
- self.putx([0, ['New state: %s' % self.state]])
- self.putp(['NEW STATE', self.state])
+ if self.first:
+ # Save the start sample and item for later (no output yet).
+ self.ss_item = self.samplenum
+ self.first = False
+ self.saved_item = self.state
+ else:
+ # Output the saved item (from the last CLK edge to the current).
+ self.es_item = self.samplenum
+ # Output the state we just switched to.
+ self.putx([jtag_states.index(self.state), [self.state]])
+ self.putp(['NEW STATE', self.state])
+ self.ss_item = self.samplenum
+ self.saved_item = self.state
# If we went from SHIFT-IR to SHIFT-IR, or SHIFT-DR to SHIFT-DR,
# collect the current TDI/TDO values (upon rising TCK edge).
self.oldpins = pins
# Get individual pin values into local variables.
- # Unused probes will have a value of > 1.
+ # Unused channels will have a value of > 1.
(tdi, tdo, tck, tms, trst, srst, rtck) = pins
# We only care about TCK edges (either rising or falling).
self.handle_rising_tck_edge(tdi, tdo, tck, tms)
self.oldtck = tck
-