diff options
| -rw-r--r-- | decoders/parallel/pd.py | 58 |
1 files changed, 50 insertions, 8 deletions
diff --git a/decoders/parallel/pd.py b/decoders/parallel/pd.py index abf48eb..e0623e7 100644 --- a/decoders/parallel/pd.py +++ b/decoders/parallel/pd.py @@ -60,6 +60,9 @@ class Pin: CLOCK = 0 DATA_0 = CLOCK + 1 DATA_N = DATA_0 + NUM_CHANNELS + # BEWARE! DATA_N points _beyond_ the data partition (Python range(3) + # semantics, useful to have to simplify other code locations). + RESET = DATA_N class Ann: ITEM, WORD = range(2) @@ -82,11 +85,14 @@ class Decoder(srd.Decoder): [ {'id': 'd%d' % i, 'name': 'D%d' % i, 'desc': 'Data line %d' % i} for i in range(NUM_CHANNELS) - ] + ] + + [{'id': 'rst', 'name': 'RST', 'desc': 'RESET line'}] ) options = ( {'id': 'clock_edge', 'desc': 'Clock edge to sample on', 'default': 'rising', 'values': ('rising', 'falling', 'either')}, + {'id': 'reset_polarity', 'desc': 'Reset line polarity', + 'default': 'low-active', 'values': ('low-active', 'high-active')}, {'id': 'wordsize', 'desc': 'Data wordsize (# bus cycles)', 'default': 0}, {'id': 'endianness', 'desc': 'Data endianness', @@ -147,6 +153,8 @@ class Decoder(srd.Decoder): self.ss_item = self.samplenum self.first = False self.saved_item = item + elif self.saved_item is None: + pass else: # Output the saved item (from the last CLK edge to the current). self.es_item = self.samplenum @@ -202,23 +210,57 @@ class Decoder(srd.Decoder): # clock signal. Either inspect samples on the configured edge of # the clock, or inspect samples upon ANY edge of ANY of the pins # which provide input data. + conds = [] + cond_idx_clock = None + cond_idx_data_0 = None + cond_idx_data_N = None + cond_idx_reset = None has_clock = self.has_channel(Pin.CLOCK) if has_clock: + cond_idx_clock = len(conds) edge = { 'rising': 'r', 'falling': 'f', 'either': 'e', }.get(self.options['clock_edge']) - conds = [{Pin.CLOCK: edge}] + conds.append({Pin.CLOCK: edge}) else: - conds = [{idx: 'e'} for idx in has_data] + cond_idx_data_0 = len(conds) + conds.extend([{idx: 'e'} for idx in has_data]) + cond_idx_data_N = len(conds) + has_reset = self.has_channel(Pin.RESET) + if has_reset: + cond_idx_reset = len(conds) + conds.append({Pin.RESET: 'e'}) + reset_active = { + 'low-active': 0, + 'high-active': 1, + }.get(self.options['reset_polarity']) # Keep processing the input stream. Assume "always zero" for # not-connected input lines. Pass data bits (all inputs except - # clock) to the handle_bits() method. + # clock and reset) to the handle_bits() method. Handle reset + # edges first and data changes then, within the same iteration. + # This results in robust operation for low-oversampled input. + in_reset = False while True: pins = self.wait(conds) - data_bits = [0 if idx is None else pins[idx] for idx in data_indices] - data_bits = data_bits[:num_item_bits] - item = bitpack(data_bits) - self.handle_bits(item, num_item_bits) + clock_edge = cond_idx_clock is not None and self.matched[cond_idx_clock] + data_edge = cond_idx_data_0 is not None and [idx for idx in range(cond_idx_data_0, cond_idx_data_N) if self.matched[idx]] + reset_edge = cond_idx_reset is not None and self.matched[cond_idx_reset] + + if reset_edge: + in_reset = pins[Pin.RESET] == reset_active + if in_reset: + self.handle_bits(None, num_item_bits) + self.saved_item = None + self.saved_word = None + self.first = True + if in_reset: + continue + + if clock_edge or data_edge: + data_bits = [0 if idx is None else pins[idx] for idx in data_indices] + data_bits = data_bits[:num_item_bits] + item = bitpack(data_bits) + self.handle_bits(item, num_item_bits) |