diff options
| -rw-r--r-- | decoders/ltc26x7/__init__.py | 25 | ||||
| -rw-r--r-- | decoders/ltc26x7/pd.py | 179 |
2 files changed, 204 insertions, 0 deletions
diff --git a/decoders/ltc26x7/__init__.py b/decoders/ltc26x7/__init__.py new file mode 100644 index 0000000..efedd4d --- /dev/null +++ b/decoders/ltc26x7/__init__.py @@ -0,0 +1,25 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2020 Analog Devices Inc. +## +## 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 3 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, see <http://www.gnu.org/licenses/>. +## + +''' +This decoder stacks on top of the 'i2c' PD and decodes the +Linear Technology LTC2607/LTC2617/LTC2627 protocol. +''' + +from .pd import Decoder diff --git a/decoders/ltc26x7/pd.py b/decoders/ltc26x7/pd.py new file mode 100644 index 0000000..ea05a25 --- /dev/null +++ b/decoders/ltc26x7/pd.py @@ -0,0 +1,179 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2020 Analog Devices Inc. +## +## 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 3 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, see <http://www.gnu.org/licenses/>. +## + +import sigrokdecode as srd + +slave_address = { + 0x00: ['GND', 'GND', 'GND', 'G'], + 0x01: ['FLOAT', 'FLOAT', 'FLOAT', 'F'], + 0x02: ['VCC', 'VCC', 'VCC', 'V'], +} + +commands = { + 0x00: ['Write Input Register', 'Write In Reg', 'Wr In Reg', 'WIR'], + 0x01: ['Update DAC', 'Update', 'U'], + 0x03: ['Write and Power Up DAC', 'Write & Power Up', 'W&PU'], + 0x04: ['Power Down DAC', 'Power Down', 'PD'], + 0x0F: ['No Operation', 'No Op', 'NO'], +} + +addresses = { + 0x00: ['DAC A', 'A'], + 0x01: ['DAC B', 'B'], + 0x0F: ['All DACs', 'All'], +} + +input_voltage_format = ['%fV', '%fV', '%.6fV', '%.2fV'] + +class Decoder(srd.Decoder): + api_version = 3 + id = 'ltc26x7' + name = 'LTC26x7' + longname = 'Linear Technology LTC26x7' + desc = 'Linear Technology LTC26x7 16-/14-/12-bit rail-to-rail DACs.' + license = 'gplv2+' + inputs = ['i2c'] + outputs = [] + tags = ['Display'] + options = ( + {'id': 'part', 'desc': 'Part', 'default': 'ltc26x7', + 'values': ('ltc2607', 'ltc2617', 'ltc2627')}, + {'id': 'ref', 'desc': 'Reference voltage', 'default': 1.5}, + ) + annotations = ( + ('slave_addr', 'Slave address'), + ('command', 'Command'), + ('address', 'Address'), + ('data', '2 byte data'), + ) + annotation_rows = ( + ('ltc26x7', 'LTC26x7 data', (0, 1, 2, 3)), + ) + + def __init__(self): + self.reset() + + def reset(self): + self.state = 'IDLE' + self.ss = -1 + self.data = 0x00 + + def start(self): + self.out_ann = self.register(srd.OUTPUT_ANN) + + def convert_ternary_str(self, n): + if n == 0: + return [0, 0, 0] + nums = [] + while n: + n, r = divmod(n, 3) + nums.append(r) + while len(nums) < 3: + nums.append(0) + return list(reversed(nums)) + + def handle_slave_addr(self, data): + if data == 0x73: + ann = ['Global address', 'Global addr', 'Glob addr', 'GA'] + self.put(self.ss, self.es, self.out_ann, [0, ann]) + return + ann = ['CA2=%s CA1=%s CA0=%s', '2=%s 1=%s 0=%s', '%s %s %s', '%s %s %s'] + addr = 0 + for i in range(7): + if i in [2, 3]: + continue + offset = i + if i > 3: + offset -= 2 + mask = 1 << i + if data & mask: + mask = 1 << offset + addr |= mask + + addr -= 0x04 + ternary_values = self.convert_ternary_str(addr) + for i in range(len(ann)): + ann[i] = ann[i] % (slave_address[ternary_values[0]][i], + slave_address[ternary_values[1]][i], + slave_address[ternary_values[2]][i]) + self.put(self.ss, self.es, self.out_ann, [0, ann]) + + def handle_cmd_addr(self, data): + cmd_val = (data >> 4) & 0x0F + dac_val = (data & 0x0F) + sm = (self.ss + self.es) // 2 + + self.put(self.ss, sm, self.out_ann, [1, commands[cmd_val]]) + self.put(sm, self.es, self.out_ann, [2, addresses[dac_val]]) + + def handle_data(self, data): + self.data = (self.data << 8) & 0xFF00 + self.data += data + if self.options['part'] == 'ltc2617': + self.data = (self.data >> 2) + self.data = (self.options['ref'] * self.data) / 0x3FFF + elif self.options['part'] == 'ltc2627': + self.data = (self.data >> 4) + self.data = (self.options['ref'] * self.data) / 0x0FFF + else: + self.data = (self.options['ref'] * self.data) / 0xFFFF + ann = [] + for format in input_voltage_format: + ann.append(format % self.data) + self.data = 0 + + self.put(self.ss, self.es, self.out_ann, [3, ann]) + + def decode(self, ss, es, data): + cmd, databyte = data + self.es = es + + # State machine. + if self.state == 'IDLE': + # Wait for an I²C START condition. + if cmd != 'START': + return + self.state = 'GET SLAVE ADDR' + elif self.state == 'GET SLAVE ADDR': + # Wait for an address write operation. + if cmd != 'ADDRESS WRITE': + return + self.ss = ss + self.handle_slave_addr(databyte) + self.ss = -1 + self.state = 'GET CMD ADDR' + elif self.state == 'GET CMD ADDR': + if cmd != 'DATA WRITE': + return + self.ss = ss + self.handle_cmd_addr(databyte) + self.ss = -1 + self.state = 'WRITE DATA' + elif self.state == 'WRITE DATA': + if cmd == 'DATA WRITE': + if self.ss == -1: + self.ss = ss + self.data = databyte + return + self.handle_data(databyte) + self.ss = -1 + elif cmd == 'STOP': + self.state = 'IDLE' + else: + return |