## ## This file is part of the sigrok project. ## ## Copyright (C) 2012 Uwe Hermann ## ## This program is free software; you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by ## the Free Software Foundation; either version 2 of the License, or ## (at your option) any later version. ## ## This program is distributed in the hope that it will be useful, ## but WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with this program; if not, write to the Free Software ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA ## # JTAG protocol decoder import sigrokdecode as srd class Decoder(srd.Decoder): api_version = 1 id = 'jtag' name = 'JTAG' longname = 'Joint Test Action Group' desc = 'Protocol for testing, debugging, and flashing ICs.' license = 'gplv2+' inputs = ['logic'] outputs = ['jtag'] probes = [ {'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 = [ # {'id': 'trst', 'name': 'TRST#', 'desc': 'Test reset'}, # {'id': 'srst', 'name': 'SRST#', 'desc': 'System reset'}, ] options = {} annotations = [ ['ASCII', 'TODO: description'], ] def __init__(self, **kwargs): # self.state = 'TEST-LOGIC-RESET' self.state = 'RUN-TEST/IDLE' self.oldstate = None self.oldpins = (-1, -1, -1, -1) self.oldtck = -1 self.bits_tdi = [] self.bits_tdo = [] def start(self, metadata): self.out_proto = self.add(srd.OUTPUT_PROTO, 'jtag') self.out_ann = self.add(srd.OUTPUT_ANN, 'jtag') def report(self): pass def advance_state_machine(self, tms): self.oldstate = self.state # Intro "tree" if self.state == 'TEST-LOGIC-RESET': self.state = 'TEST-LOGIC-RESET' if (tms) else 'RUN-TEST/IDLE' elif self.state == 'RUN-TEST/IDLE': self.state = 'SELECT-DR-SCAN' if (tms) else 'RUN-TEST/IDLE' # DR "tree" elif self.state == 'SELECT-DR-SCAN': self.state = 'SELECT-IR-SCAN' if (tms) else 'CAPTURE-DR' elif self.state == 'CAPTURE-DR': self.state = 'EXIT1-DR' if (tms) else 'SHIFT-DR' elif self.state == 'SHIFT-DR': self.state = 'EXIT1-DR' if (tms) else 'SHIFT-DR' elif self.state == 'EXIT1-DR': self.state = 'UPDATE-DR' if (tms) else 'PAUSE-DR' elif self.state == 'PAUSE-DR': self.state = 'EXIT2-DR' if (tms) else 'PAUSE-DR' elif self.state == 'EXIT2-DR': self.state = 'UPDATE-DR' if (tms) else 'SHIFT-DR' elif self.state == 'UPDATE-DR': self.state = 'SELECT-DR-SCAN' if (tms) else 'RUN-TEST/IDLE' # IR "tree" elif self.state == 'SELECT-IR-SCAN': self.state = 'TEST-LOGIC-RESET' if (tms) else 'CAPTURE-IR' elif self.state == 'CAPTURE-IR': self.state = 'EXIT1-IR' if (tms) else 'SHIFT-IR' elif self.state == 'SHIFT-IR': self.state = 'EXIT1-IR' if (tms) else 'SHIFT-IR' elif self.state == 'EXIT1-IR': self.state = 'UPDATE-IR' if (tms) else 'PAUSE-IR' elif self.state == 'PAUSE-IR': self.state = 'EXIT2-IR' if (tms) else 'PAUSE-IR' elif self.state == 'EXIT2-IR': self.state = 'UPDATE-IR' if (tms) else 'SHIFT-IR' 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.put(self.ss, self.es, self.out_ann, [0, ['New state: %s' % self.state]]) self.put(self.ss, self.es, self.out_proto, ['NEW STATE', 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). if self.state.startswith('SHIFT-') and self.oldstate == self.state: self.bits_tdi.insert(0, tdi) self.bits_tdo.insert(0, tdo) # TODO: ANN/PROTO output. # self.put(self.ss, self.es, self.out_ann, # [0, ['TDI add: ' + str(tdi)]]) # self.put(self.ss, self.es, self.out_ann, # [0, ['TDO add: ' + str(tdo)]]) # Output all TDI/TDO bits if we just switched from SHIFT-* to EXIT1-*. if self.oldstate.startswith('SHIFT-') and \ self.state.startswith('EXIT1-'): t = self.state[-2:] + ' TDI' b = ''.join(map(str, self.bits_tdi)) s = t + ': ' + b + ', ' + str(len(self.bits_tdi)) + ' bits' self.put(self.ss, self.es, self.out_ann, [0, [s]]) self.put(self.ss, self.es, self.out_proto, [t, b]) self.bits_tdi = [] t = self.state[-2:] + ' TDO' b = ''.join(map(str, self.bits_tdo)) s = t + ': ' + b + ', ' + str(len(self.bits_tdo)) + ' bits' self.put(self.ss, self.es, self.out_ann, [0, [s]]) self.put(self.ss, self.es, self.out_proto, [t, b]) self.bits_tdo = [] def decode(self, ss, es, data): for (samplenum, pins) in data: # If none of the pins changed, there's nothing to do. if self.oldpins == pins: continue # Store current pin values for the next round. self.oldpins = pins # Get individual pin values into local variables. # TODO: Handle optional pins (TRST, SRST). (tdi, tdo, tck, tms) = pins # We only care about TCK edges (either rising or falling). if (self.oldtck == tck): continue # Store start/end sample for later usage. self.ss, self.es = ss, es # self.put(self.ss, self.es, self.out_ann, # [0, ['tdi:%s, tdo:%s, tck:%s, tms:%s' \ # % (tdi, tdo, tck, tms)]]) if (self.oldtck == 0 and tck == 1): self.handle_rising_tck_edge(tdi, tdo, tck, tms) self.oldtck = tck