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1##
2## This file is part of the libsigrokdecode project.
3##
4## Copyright (C) 2012-2015 Uwe Hermann <uwe@hermann-uwe.de>
5##
6## This program is free software; you can redistribute it and/or modify
7## it under the terms of the GNU General Public License as published by
8## the Free Software Foundation; either version 2 of the License, or
9## (at your option) any later version.
10##
11## This program is distributed in the hope that it will be useful,
12## but WITHOUT ANY WARRANTY; without even the implied warranty of
13## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14## GNU General Public License for more details.
15##
16## You should have received a copy of the GNU General Public License
17## along with this program; if not, see <http://www.gnu.org/licenses/>.
18##
19
20import sigrokdecode as srd
21
22dacs = {
23 0: 'DACA',
24 1: 'DACB',
25 2: 'DACC',
26 3: 'DACD',
27}
28
29class Decoder(srd.Decoder):
30 api_version = 3
31 id = 'tlc5620'
32 name = 'TI TLC5620'
33 longname = 'Texas Instruments TLC5620'
34 desc = 'Texas Instruments TLC5620 8-bit quad DAC.'
35 license = 'gplv2+'
36 inputs = ['logic']
37 outputs = ['tlc5620']
38 tags = ['IC', 'Analog/digital']
39 channels = (
40 {'id': 'clk', 'name': 'CLK', 'desc': 'Serial interface clock'},
41 {'id': 'data', 'name': 'DATA', 'desc': 'Serial interface data'},
42 )
43 optional_channels = (
44 {'id': 'load', 'name': 'LOAD', 'desc': 'Serial interface load control'},
45 {'id': 'ldac', 'name': 'LDAC', 'desc': 'Load DAC'},
46 )
47 options = (
48 {'id': 'vref_a', 'desc': 'Reference voltage DACA (V)', 'default': 3.3},
49 {'id': 'vref_b', 'desc': 'Reference voltage DACB (V)', 'default': 3.3},
50 {'id': 'vref_c', 'desc': 'Reference voltage DACC (V)', 'default': 3.3},
51 {'id': 'vref_d', 'desc': 'Reference voltage DACD (V)', 'default': 3.3},
52 )
53 annotations = (
54 ('dac-select', 'DAC select'),
55 ('gain', 'Gain'),
56 ('value', 'DAC value'),
57 ('data-latch', 'Data latch point'),
58 ('ldac-fall', 'LDAC falling edge'),
59 ('bit', 'Bit'),
60 ('reg-write', 'Register write'),
61 ('voltage-update', 'Voltage update'),
62 ('voltage-update-all', 'Voltage update (all DACs)'),
63 ('invalid-cmd', 'Invalid command'),
64 )
65 annotation_rows = (
66 ('bits', 'Bits', (5,)),
67 ('fields', 'Fields', (0, 1, 2)),
68 ('registers', 'Registers', (6, 7)),
69 ('voltage-updates', 'Voltage updates', (8,)),
70 ('events', 'Events', (3, 4)),
71 ('errors', 'Errors', (9,)),
72 )
73
74 def __init__(self):
75 self.reset()
76
77 def reset(self):
78 self.bits = []
79 self.ss_dac_first = None
80 self.ss_dac = self.es_dac = 0
81 self.ss_gain = self.es_gain = 0
82 self.ss_value = self.es_value = 0
83 self.dac_select = self.gain = self.dac_value = None
84 self.dacval = {'A': '?', 'B': '?', 'C': '?', 'D': '?'}
85 self.gains = {'A': '?', 'B': '?', 'C': '?', 'D': '?'}
86
87 def start(self):
88 self.out_ann = self.register(srd.OUTPUT_ANN)
89
90 def handle_11bits(self):
91 # Only look at the last 11 bits, the rest is ignored by the TLC5620.
92 if len(self.bits) > 11:
93 self.bits = self.bits[-11:]
94
95 # If there are less than 11 bits, something is probably wrong.
96 if len(self.bits) < 11:
97 ss, es = self.samplenum, self.samplenum
98 if len(self.bits) >= 2:
99 ss = self.bits[0][1]
100 es = self.bits[-1][1] + (self.bits[1][1] - self.bits[0][1])
101 self.put(ss, es, self.out_ann, [9, ['Command too short']])
102 self.bits = []
103 return False
104
105 self.ss_dac = self.bits[0][1]
106 self.es_dac = self.ss_gain = self.bits[2][1]
107 self.es_gain = self.ss_value = self.bits[3][1]
108 self.clock_width = self.es_gain - self.ss_gain
109 self.es_value = self.bits[10][1] + self.clock_width # Guessed.
110
111 if self.ss_dac_first is None:
112 self.ss_dac_first = self.ss_dac
113
114 s = ''.join(str(i[0]) for i in self.bits[:2])
115 self.dac_select = s = dacs[int(s, 2)]
116 self.put(self.ss_dac, self.es_dac, self.out_ann,
117 [0, ['DAC select: %s' % s, 'DAC sel: %s' % s,
118 'DAC: %s' % s, 'D: %s' % s, s, s[3]]])
119
120 self.gain = g = 1 + self.bits[2][0]
121 self.put(self.ss_gain, self.es_gain, self.out_ann,
122 [1, ['Gain: x%d' % g, 'G: x%d' % g, 'x%d' % g]])
123
124 s = ''.join(str(i[0]) for i in self.bits[3:])
125 self.dac_value = v = int(s, 2)
126 self.put(self.ss_value, self.es_value, self.out_ann,
127 [2, ['DAC value: %d' % v, 'Value: %d' % v, 'Val: %d' % v,
128 'V: %d' % v, '%d' % v]])
129
130 # Emit an annotation for each bit.
131 for i in range(1, 11):
132 self.put(self.bits[i - 1][1], self.bits[i][1], self.out_ann,
133 [5, [str(self.bits[i - 1][0])]])
134 self.put(self.bits[10][1], self.bits[10][1] + self.clock_width,
135 self.out_ann, [5, [str(self.bits[10][0])]])
136
137 self.bits = []
138
139 return True
140
141 def handle_falling_edge_load(self):
142 if not self.handle_11bits():
143 return
144 s, v, g = self.dac_select, self.dac_value, self.gain
145 self.put(self.samplenum, self.samplenum, self.out_ann,
146 [3, ['Falling edge on LOAD', 'LOAD fall', 'F']])
147 vref = self.options['vref_%s' % self.dac_select[3].lower()]
148 v = '%.2fV' % (vref * (v / 256) * self.gain)
149 if self.ldac == 0:
150 # If LDAC is low, the voltage is set immediately.
151 self.put(self.ss_dac, self.es_value, self.out_ann,
152 [7, ['Setting %s voltage to %s' % (s, v),
153 '%s=%s' % (s, v)]])
154 else:
155 # If LDAC is high, the voltage is not set immediately, but rather
156 # stored in a register. When LDAC goes low all four DAC voltages
157 # (DAC A/B/C/D) will be set at the same time.
158 self.put(self.ss_dac, self.es_value, self.out_ann,
159 [6, ['Setting %s register value to %s' % \
160 (s, v), '%s=%s' % (s, v)]])
161 # Save the last value the respective DAC was set to.
162 self.dacval[self.dac_select[-1]] = str(self.dac_value)
163 self.gains[self.dac_select[-1]] = self.gain
164
165 def handle_falling_edge_ldac(self):
166 self.put(self.samplenum, self.samplenum, self.out_ann,
167 [4, ['Falling edge on LDAC', 'LDAC fall', 'LDAC', 'L']])
168
169 # Don't emit any annotations if we didn't see any register writes.
170 if self.ss_dac_first is None:
171 return
172
173 # Calculate voltages based on Vref and the per-DAC gain.
174 dacval = {}
175 for key, val in self.dacval.items():
176 if val == '?':
177 dacval[key] = '?'
178 else:
179 vref = self.options['vref_%s' % key.lower()]
180 v = vref * (int(val) / 256) * self.gains[key]
181 dacval[key] = '%.2fV' % v
182
183 s = ''.join(['DAC%s=%s ' % (d, dacval[d]) for d in 'ABCD']).strip()
184 self.put(self.ss_dac_first, self.samplenum, self.out_ann,
185 [8, ['Updating voltages: %s' % s, s, s.replace('DAC', '')]])
186 self.ss_dac_first = None
187
188 def handle_new_dac_bit(self, datapin):
189 self.bits.append([datapin, self.samplenum])
190
191 def decode(self):
192 while True:
193 # DATA is shifted in the DAC on the falling CLK edge (MSB-first).
194 # A falling edge of LOAD will latch the data.
195
196 # Wait for one (or multiple) of the following conditions:
197 # a) Falling edge on CLK, and/or
198 # b) Falling edge on LOAD, and/or
199 # b) Falling edge on LDAC
200 pins = self.wait([{0: 'f'}, {2: 'f'}, {3: 'f'}])
201 self.ldac = pins[3]
202
203 # Handle those conditions (one or more) that matched this time.
204 if self.matched[0]:
205 self.handle_new_dac_bit(pins[1])
206 if self.matched[1]:
207 self.handle_falling_edge_load()
208 if self.matched[2]:
209 self.handle_falling_edge_ldac()