Gather 8 bits of data (or track processing progress).
(self, ss, es, bit)
| 367 | return |
| 368 | |
| 369 | def handle_data_bit(self, ss, es, bit): |
| 370 | '''Gather 8 bits of data (or track processing progress).''' |
| 371 | |
| 372 | # Switch late from DATA to either OUT or PROC. We can tell the |
| 373 | # type and potentially fixed length at the end of CMD already, |
| 374 | # but a START/STOP condition may void this information. So we |
| 375 | # do the switch at the first data bit after CMD. |
| 376 | # In the OUT case data bytes get accumulated, until either the |
| 377 | # expected byte count is reached, or another CMD starts. In the |
| 378 | # PROC case a high I/O level terminates execution. |
| 379 | if self.state == 'DATA': |
| 380 | if self.out_len: |
| 381 | self.state = 'OUT' |
| 382 | elif self.cmd_proc: |
| 383 | self.state = 'PROC' |
| 384 | self.processing_start(ss or es, es or ss, bit == 1) |
| 385 | else: |
| 386 | # Implementor's note: Handle unknown situations like |
| 387 | # outgoing data bytes, for the user's convenience. This |
| 388 | # will show OUT bytes even if it's just processing CLK |
| 389 | # cycles with constant or irrelevant I/O bit patterns. |
| 390 | self.state = 'OUT' |
| 391 | if self.state == 'PROC': |
| 392 | high = bit == 1 |
| 393 | if ss is not None: |
| 394 | self.processing_update(ss, 0, high) |
| 395 | if es is not None: |
| 396 | self.processing_update(es, 1, high) |
| 397 | if high: |
| 398 | self.flush_queued() |
| 399 | return |
| 400 | |
| 401 | # This routine gets called two times per bit value. Track the |
| 402 | # bit's value and ss timestamp when the bit period starts. And |
| 403 | # update the es timestamp at the end of the bit's validity. |
| 404 | if ss is not None: |
| 405 | self.bits.append([bit, ss, es or ss]) |
| 406 | return |
| 407 | if es is None: |
| 408 | # Unexpected invocation. Could be a glitch or invalid input |
| 409 | # data, or an interaction with RESET/START/STOP conditions. |
| 410 | self.bits = [] |
| 411 | return |
| 412 | if not self.bits: |
| 413 | return |
| 414 | if bit is not None: |
| 415 | self.bits[-1][0] = bit |
| 416 | # TODO Check for consistent bit level at ss and es when |
| 417 | # the information was available? Is bit data sampled at |
| 418 | # different clock edges depending whether data is sent |
| 419 | # or received? |
| 420 | self.bits[-1][2] = es |
| 421 | # Emit the bit's annotation. See if a byte was received. |
| 422 | bit, ss, es = self.bits[-1] |
| 423 | cls, texts = self.lookup_proto_ann_txt('BIT_SYM', {'bit': bit}) |
| 424 | self.putx(ss, es, cls, texts) |
| 425 | if len(self.bits) < 8: |
| 426 | return |
no test coverage detected