Files
sigrok-mfm/mfm/pd.py

1276 lines
44 KiB
Python

## ---------------------------------------------------------------------------
## FILE: decoders\mfm\pd.py
## PURPOSE: Decode a floppy disk FM or MFM pulse stream.
##
## Copyright (C) 2017 David C. Wiens <dcwiens@sardis-technologies.com>
## Initial version created 2017-Mar-14.
## Last modified 2018-Mar-24 21:36 PDT.
## ---------------------------------------------------------------------------
## To Do:
## - create user instructions
## - specify folder and file name for decoded output file
## - create folder if it doesn't exist
## - Windows vs. Linux vs. Macintosh
## - make sure all decoder features work with both PulseView and sigrok-cli
## - how to display output to stderr with Release version of PulseView?
## - include example files (raw binary digital, session files with digital+analog)
## - include test files and related information for regression testing
## Suggested enhancements:
## - create another separate report file for decoded sectors, showing
## cyl, sid, sec, DRcrcok
## - support MMFM
## ---------------------------------------------------------------------------
##
## This file is part of the libsigrokdecode project.
##
## 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, see <http://www.gnu.org/licenses/>.
##
import sigrokdecode as srd
from collections import deque
from array import *
from struct import *
import sys
import os
# ----------------------------------------------------------------------------
# PURPOSE: Handle missing sample rate.
# ----------------------------------------------------------------------------
class SamplerateError(Exception):
pass
# ----------------------------------------------------------------------------
# PURPOSE: Subclass and initialize the Decoder class.
# ----------------------------------------------------------------------------
class Decoder(srd.Decoder):
api_version = 3
id = 'mfm'
name = 'MFM'
longname = 'FM/MFM decoding'
desc = 'Decode floppy disk FM or MFM pulse stream.'
license = 'gplv2+'
inputs = ['logic']
outputs = ['mfm']
tags = ['Disk', 'PC']
channels = (
{'id': 'data', 'type': 0, 'name': 'Read data', 'desc': 'channel 0', 'idn':'dec_mfm_chan_data'},
)
optional_channels = (
{'id': 'extra', 'type': 107, 'name': 'Extra pulses', 'desc': 'channel 1', 'idn':'dec_mfm_chan_extra'},
{'id': 'suppress', 'type': 107, 'name': 'Suppress pulses', 'desc': 'channel 2', 'idn':'dec_mfm_chan_suppress'},
)
annotations = (
('erw', 'erw'),
('unk', 'unknown'),
('clk', 'clock'),
('dat', 'data'),
('erb', 'erb'),
('bit', 'bit'),
('byt', 'byte'),
('mrk', 'mark'),
('rec', 'record'),
('cre', 'crc error'),
('crc', 'crc'),
('rpt', 'rpt'),
('pfx', 'prefix'),
('pul', 'pulse'),
('erp', 'erp'),
('err', 'error'),
)
annotation_rows = (
('pulses', 'Pulses', (13, 14,)),
('wins', 'win', (0, 1, 2, 3,)),
('prefixes', 'Prefixes', (12,)),
('bits', 'Bits', (4, 5,)),
('bytes', 'Bytes', (6,)),
('fields', 'Fields', (7, 8, 9, 10,)),
('errors', 'Errors', (15,)),
)
options = (
{'id': 'leading_edge', 'desc': 'Leading edge',
'default': 'rising', 'values': ('rising', 'falling')},
{'id': 'data_rate', 'desc': 'Data rate (bps)',
'default': '5000000', 'values': ('125000', '150000',
'250000', '300000', '500000',
'5000000', '10000000')},
{'id': 'encoding', 'desc': 'Encoding',
'default': 'MFM', 'values': ('FM', 'MFM')},
{'id': 'type', 'desc': 'Type',
'default': 'HDD', 'values': ('FDD', 'HDD')},
{'id': 'sect_len', 'desc': 'Sector length',
'default': '512', 'values': ('128', '256', '512', '1024')},
{'id': 'header_bytes', 'desc': 'Header bytes',
'default': '8', 'values': ('7', '8')},
{'id': 'header_crc_bits', 'desc': 'Header field CRC bits',
'default': '16', 'values': ('16', '32')},
{'id': 'data_crc_bits', 'desc': 'Data field CRC bits',
'default': '32', 'values': ('16', '32', '56')},
{'id': 'crc16_poly', 'desc': 'CRC16 Polynomial',
'default': '1021'},
{'id': 'crc32_poly', 'desc': 'CRC32 Polynomial',
'default': '00A00805'},
{'id': 'dsply_pfx', 'desc': 'Display all MFM prefix bytes',
'default': 'no', 'values': ('yes', 'no')},
{'id': 'dsply_sn', 'desc': 'Display sample numbers',
'default': 'yes', 'values': ('yes', 'no')},
)
# ------------------------------------------------------------------------
# PURPOSE: Class constructor/initializer.
# ------------------------------------------------------------------------
def __init__(self):
self.reset()
def reset(self):
# Initialize pre-defined variables.
self.samplerate = None
self.last_samplenum = None
self.last_n = deque()
self.chunks = 0
# Define (and initialize) various custom variables.
self.samplerateMSps = 0.0 # sampling rate in MS/s (15.0, 16.0, 20.0, etc.)
self.rising_edge = True # True = leading edge is rising, False = falling
self.data_rate = 0.0 # 125000.0, 150000.0, 250000.0, 300000.0, 500000.0
self.encodingFM = False # True = FM encoding, False = MFM encoding
self.fdd = True # True = FDD, False = HDD
self.byte_start = 0 # start of byte (sample number)
self.byte_end = 0 # end of byte (sample number)
self.field_start = 0 # start of field (sample number)
self.pb_state = 0 # processing byte state = 1..10
self.sector_len = 0 # 128, 256, 512, 1024
self.byte_cnt = 0 # number of bytes left to process in field (1024/512/256/128/4/2..0)
self.dsply_pfx = False # True = display all prefix bytes found, False = don't
self.dsply_sn = True # True = display sample number in window annotation, False = don't
self.header_crc_bytes = 2 # 16 or 32 bits for data field CRC/ECC
self.block_header_byte = 0 # Byte used to indicate the start of a block
self.data_crc_bytes = 4 # 16, 32 or 56 bits for data field CRC/ECC
self.samples30usec = 0 # number of samples in 30 usec.
self.IDlastAM = -1 # sample number of most recent ID Address Mark, -1 = not found or not valid
self.max_id_data_gap = 0 # maximum gap between ID Address Mark and following Data Address Mark (samples)
self.IDcyl = 0 # cylinder number field in ID record (0..244)
self.IDsid = 0 # side number field in ID record (0..1)
self.IDsec = 0 # sector number field in ID record (0..244)
self.IDlenc = 0 # sector length code field in ID record (0..3)
self.IDlenv = 0 # sector length (from code field) in ID record (128/256/512/1024)
self.IDcrc = 0 # ID record 16-bit CRC
self.DRmark = 0 # Data Address Mark (F8h/F9h/FAh/FBh)
self.DRcrc = 0 # Data record 16/32/56-bit CRC/ECC
self.DRcrcok = False # True = Data record CRC/ECC OK, False = error
self.DRsec = array('B', [0 for i in range(1024)]) # Data record (128/256/512/1024 bytes)
self.report_displayed = False # True = summary report already displayed, False = not displayed yet
self.crc16_accum = 0
self.crc32_accum = 0
self.crc56_accum = 0
# FIFO (using circular buffers) of starting/ending sample numbers
# and data values for 33 half-bit-cell windows. Data values are
# number of leading edges per window (0..n).
self.fifo_ws = array('l', [0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0,])
self.fifo_we = array('l', [0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0,])
self.fifo_wv = array('i', [0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0,])
self.fifo_wp = -1 # index where last FIFO entry was written (0..32)
self.fifo_rp = 0 # index where to read next FIFO entry (0..32)
self.fifo_cnt = 0 # number of entries currently in FIFO (0..33)
# Define and zero statistics counters.
self.IM = 0 # number of Index Marks
self.IDR = 0 # number of ID Records
self.DR = 0 # number of Data Records
self.CRC_OK = 0 # number of OK CRCs
self.CRC_err = 0 # number of error CRCs
self.EiPW = 0 # number of leading edges found in a previous window
self.CkEr = 0 # number of bits with clocking errors
self.OoTI = 0 # number of out-of-tolerance leading edge intervals
self.Intrvls = 0 # number of leading edge intervals
# Define binary output file.
self.binfile = None
# ------------------------------------------------------------------------
# PURPOSE: Get the data sample rate entered by the user.
# ------------------------------------------------------------------------
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
self.samplerateMSps = self.samplerate / 1000000.0
# ------------------------------------------------------------------------
# PURPOSE: Various initialization when decoder started.
# ------------------------------------------------------------------------
def start(self):
# Initialize options selected by the user in the dialog box.
self.rising_edge = True if self.options['leading_edge'] == 'rising' else False
self.data_rate = float(self.options['data_rate'])
self.encodingFM = True if self.options['encoding'] == 'FM' else False
self.fdd = True if self.options['type'] == 'FDD' else False
self.sector_len = int(self.options['sect_len'])
self.dsply_pfx = True if self.options['dsply_pfx'] == 'yes' else False
self.dsply_sn = True if self.options['dsply_sn'] == 'yes' else False
self.header_crc_bytes = int(self.options['header_crc_bits']) / 8
self.header_bytes = int(self.options['header_bytes'])
self.data_crc_bytes = int(self.options['data_crc_bits']) / 8
self.crc16_poly = int(self.options['crc16_poly'], 16)
self.crc32_poly = int(self.options['crc32_poly'], 16)
# Calculate number of samples in 30 usec.
self.samples30usec = int(self.samplerate / 1000000.0 * 30.0)
# Calculate maximum number of samples allowed between ID and Data Address Marks.
if self.encodingFM:
self.max_id_data_gap = (self.samplerate / self.data_rate) * 8 * (1 + 4 + 2 + 30 + 10)
else:
self.max_id_data_gap = (self.samplerate / self.data_rate) * 8 * (4 + 4 + 2 + 43 + 15)
# Other initialization.
self.out_ann = self.register(srd.OUTPUT_ANN)
self.initial_pins = [1 if self.rising_edge == True else 0]
# ------------------------------------------------------------------------
# PURPOSE: Initialize the CRC accumulator.
# ------------------------------------------------------------------------
def iniz_crc(self):
self.crc16_accum = 0xFFFF
self.crc32_accum = 0xFFFFFFFF
self.crc56_accum = 0xFFFFFFFFFFFFFF
# ------------------------------------------------------------------------
# PURPOSE: Update the 16-bit CRC accumulator with one data byte.
# NOTES:
# - Processes 4 bits at a time, using table lookup.
# - The CRC-CCITT polynomial is x16 + x12 + x5 + 1.
# IN: byte 00h..FFh
# ------------------------------------------------------------------------
def update_crc16(self, byte):
self.crc16_accum = (self.crc16_accum ^ (byte << 8)) & 0xFFFF
for i in range(8):
if (self.crc16_accum & 0x8000) == 0x8000:
self.crc16_accum = ((self.crc16_accum << 1) ^ self.crc16_poly) & 0xFFFF
else:
self.crc16_accum = (self.crc16_accum << 1) & 0xFFFF
# ------------------------------------------------------------------------
# PURPOSE: Update the 32-bit CRC accumulator with one data byte.
# NOTES:
# - Processes 4 bits at a time, using table lookup.
# - The CRC-32 polynomial is x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1.
# IN: byte 00h..FFh
# ------------------------------------------------------------------------
def update_crc32(self, byte):
self.crc32_accum = (self.crc32_accum ^ (byte << 24)) & 0xFFFFFFFF
for i in range(8):
if (self.crc32_accum & 0x80000000) == 0x80000000:
self.crc32_accum = ((self.crc32_accum << 1) ^ self.crc32_poly) & 0xFFFFFFFF
else:
self.crc32_accum = (self.crc32_accum << 1) & 0xFFFFFFFF
def update_crc56(self, byt):
pass
# dont know how yet :)
# ------------------------------------------------------------------------
# PURPOSE: Increment FIFO read pointer and decrement entry count.
# ------------------------------------------------------------------------
def inc_fifo_rp(self):
self.fifo_rp += 1
if self.fifo_rp > 32:
self.fifo_rp -= 33
self.fifo_cnt -= 1
# ------------------------------------------------------------------------
# PURPOSE: Increment FIFO write pointer and increment entry count.
# ------------------------------------------------------------------------
def inc_fifo_wp(self):
self.fifo_wp += 1
if self.fifo_wp > 32:
self.fifo_wp -= 33
self.fifo_cnt += 1
# ------------------------------------------------------------------------
# PURPOSE: Display annotations for 16 windows and 8 bits of one byte, using
# FIFO data.
# NOTES:
# - On entry the FIFO must have exactly 33 or 17 entries in it, and on
# exit the FIFO will have 16 fewer entries in it (17 or 1).
# - Half-bit-cell windows are processed in time order from the last window
# of the previous byte, to the second last window of the current byte.
# - Bits are processed in time order from the first bit (msb, bit 7) to
# the last bit (lsb, bit 0) of the current byte.
# - Need to use a while loop instead of a for loop due to some strange bug,
# possibly in Python itself?
# IN: spclk True = special clocking, don't display clock errors to stderr
# False = normal clocking, display clock errors to stderr
# self.fifo_rp, self.fifo_cnt
# OUT: self.byte_start, self.byte_end, self.fifo_rp, self.fifo_cnt updated
# ------------------------------------------------------------------------
def display_bits(self, spclk):
# Define (and initialize) function variables.
win_start = 0 # start of window (sample number)
win_end = 0 # end of window (sample number)
win_val = 0 # window value (0..n)
bit_start = 0 # start of bit (sample number)
bit_end = 0 # end of bit (sample number)
bit_val = 0 # bit value (0..1)
shift3 = 0 # 3-bit shift register of window values
self.byte_start = -1 # start of byte (sample number, -1 = not set yet)
# Process each of the 8 data bits and 17 windows in turn.
# Start with bit 8, which is bit 0 of the previous byte.
bitn = 8
while True:
# Display annotation for second (data) half-bit-cell window of a pair,
# starting with the data window of the last bit of the previous byte.
# The last window of the current byte is read but not removed from the
# FIFO, and isn't displayed.
win_start = self.fifo_ws[self.fifo_rp]
win_end = self.fifo_we[self.fifo_rp]
win_val = self.fifo_wv[self.fifo_rp]
if bitn > 0:
self.inc_fifo_rp()
shift3 = ((shift3 & 0x03) << 1) + (1 if win_val > 1 else win_val)
if bitn > 0:
if self.dsply_sn:
if win_val > 1:
self.put(win_end - 1, win_end, self.out_ann, [15, ['Err']])
self.put(win_start, win_end, self.out_ann,
[0, ['%d d (extra pulse in win) s%d' % (win_val, win_start), '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[3, ['%d d s%d' % (win_val, win_start), '%d' % win_val]])
else:
if win_val > 1:
self.put(win_end - 1, win_end, self.out_ann, [15, ['Err']])
self.put(win_start, win_end, self.out_ann,
[0, ['%d d (extra pulse in win)' % win_val, '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[3, ['%d d' % win_val, '%d' % win_val]])
bit_end = win_end
bit_val = 1 if win_val > 1 else win_val
# Display annotation for bit using value in data window. The last
# bit for the previous byte has already been displayed previously.
if bitn < 8:
if ((not self.encodingFM) and (shift3 == 0 or shift3 == 3 or shift3 == 6 or shift3 == 7)) \
or ( self.encodingFM and (shift3 == 0 or shift3 == 1 or shift3 == 4 or shift3 == 5)):
if not spclk:
self.put(bit_end - 1, bit_end, self.out_ann, [15, ['Err']])
self.CkEr += 1
self.put(bit_start, bit_end, self.out_ann, [4, ['%d (clock error)' % bit_val, '%d' % bit_val]])
self.put(bit_end - 1, bit_end, self.out_ann, [15, ['Err']])
else:
self.put(bit_start, bit_end, self.out_ann, [5, ['%d' % bit_val]])
if bitn == 0:
break
# Display annotation for first (clock) half-bit-cell window of a pair.
win_start = self.fifo_ws[self.fifo_rp]
win_end = self.fifo_we[self.fifo_rp]
win_val = self.fifo_wv[self.fifo_rp]
self.inc_fifo_rp()
shift3 = ((shift3 & 0x03) << 1) + (1 if win_val > 1 else win_val)
if self.dsply_sn:
if win_val > 1:
self.put(win_end - 1, win_end, self.out_ann, [15, ['Err']])
self.put(win_start, win_end, self.out_ann,
[0, ['%d c (extra pulse in win) s%d' % (win_val, win_start), '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[2, ['%d c s%d' % (win_val, win_start), '%d' % win_val]])
else:
if win_val > 1:
self.put(win_end - 1, win_end, self.out_ann, [15, ['Err']])
self.put(win_start, win_end, self.out_ann,
[0, ['%d c (extra pulse in win)' % win_val, '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[2, ['%d c' % win_val, '%d' % win_val]])
bit_start = win_start
if self.byte_start == -1:
self.byte_start = bit_start
bitn -= 1
# end while
self.byte_end = bit_end
def crc(self, val):
self.update_crc16(val)
self.update_crc32(val)
self.update_crc56(val)
# ------------------------------------------------------------------------
# PURPOSE: Display annotations for one byte and its 8 bits and 16 windows.
# NOTES:
# - On entry the FIFO must have exactly 33 or 17 entries in it, and on
# exit the FIFO will have 16 fewer entries in it (17 or 1).
# IN: val byte value (00h..FFh)
# spclk True = special clocking, don't display clock errors to stderr
# False = normal clocking, display clock errors to stderr
# self.fifo_rp
# OUT: self.byte_start, self.byte_end, self.fifo_rp updated
# ------------------------------------------------------------------------
def display_byte(self, val, spclk):
# Display annotations for windows and bits of this byte.
self.display_bits(spclk)
# Display annotation for this byte.
short_ann = '%02X' % val
if val >= 32 and val < 127:
long_ann = '%02X \'%c\'' % (val, val)
else:
long_ann = short_ann
self.put(self.byte_start, self.byte_end, self.out_ann,
[6, [long_ann, short_ann]])
# ------------------------------------------------------------------------
# Display an annotation for a field.
# IN: typ type of field = 'x'/'i'/'I'/'d'/'D'/'e'/'c'
# self.field_start, self.byte_end
# OUT: self.field_start updated
# ------------------------------------------------------------------------
def display_field(self, typ):
if typ == 'x':
self.put(self.field_start, self.byte_end, self.out_ann,
[7, ['Index Mark', 'IM', 'I']])
elif typ == 'i':
self.put(self.field_start, self.byte_end, self.out_ann,
[7, ['ID Address Mark', 'AM', 'A']])
elif typ == 'd':
self.put(self.field_start, self.byte_end, self.out_ann,
[7, ['Data Address Mark', 'AM', 'A']])
elif typ == 'I':
self.put(self.field_start, self.byte_end, self.out_ann,
[8, ['ID Record: cyl=%d, sid=%d, sec=%d, len=%d' %
(self.IDcyl, self.IDsid, self.IDsec, self.IDlenv),
'ID Record', 'Irec', 'R']])
elif typ == 'D':
self.put(self.field_start, self.byte_end, self.out_ann,
[8, ['Data Record', 'Drec', 'R']])
elif typ == 'e':
self.put(self.byte_end - 1, self.byte_end, self.out_ann, [15, ['Err']])
self.put(self.field_start, self.byte_end, self.out_ann,
[9, ['CRC error %02X' % self.crc16_accum or self.crc32_accum or self.crc56_accum, 'CRC error', 'CRC', 'C']])
elif typ == 'c':
self.put(self.field_start, self.byte_end, self.out_ann,
[10, ['CRC OK', 'CRC', 'C']])
self.field_start = self.byte_end
# ------------------------------------------------------------------------
# PURPOSE: Decode the ID Record subfields.
# IN: fld_code 4 = cylinder, 3 = side, 2 = sector, 1 = length code
# val 8-bit subfield value (00h..FFh)
# ------------------------------------------------------------------------
def decode_id_rec(self, fld_code, val):
if self.header_bytes == 7:
self.decode_id_rec_7byte(fld_code, val)
else:
self.decode_id_rec_8byte(fld_code,val)
def decode_id_rec_7byte(self, fld_code, val):
if fld_code == 3:
msb = self.block_header_byte ^ 0xFE
self.IDcyl = val | (msb << 8)
elif fld_code == 2:
self.IDsid = val & 0x0F
self.IDlenc = 512
if val & 0xF0 == 0:
self.IDlenv = 128
elif val & 0xF0 == 0x10:
self.IDlenv = 256
elif val & 0xF0 == 0x20:
self.IDlenv = 512
elif val & 0xF0 == 0x30:
self.IDlenv = 1024
else:
self.IDlenv = 0
if self.IDlenv != self.sector_len:
self.IDlastAM = -1
elif fld_code == 1:
self.IDsec = val
def decode_id_rec_8byte(self, fld_code, val):
if fld_code == 4:
self.IDcyl = val
elif fld_code == 3:
self.IDsid = val
elif fld_code == 2:
self.IDsec = val
elif fld_code == 1:
self.IDlenc = val
if val == 0:
self.IDlenv = 128
elif val == 1:
self.IDlenv = 256
elif val == 2:
self.IDlenv = 512
elif val == 3:
self.IDlenv = 1024
else:
self.IDlenv = 0
if self.IDlenv != self.sector_len:
self.IDlastAM = -1
# ------------------------------------------------------------------------
# PURPOSE: Process one byte extracted from FM pulse stream.
# NOTES:
# - Index/Address Marks are preceded by a 00h byte.
# - When called with 0x1FC/0x1FE/0x1F8..0x1FB values, the FIFO must have
# exactly 33 entries in it, otherwise it must have exactly 17 entries.
# On exit the FIFO will have exactly 1 entry in it.
# IN: val 00h..FFh normal byte
# 1FCh = 00h + FCh with D7h clock = Index Mark
# 1FEh = 00h + FEh with C7h clock = ID Address Mark
# 1FBh = 00h + FBh with C7h clock = normal Data Address Mark
# 1F8h..1FAh = 00h + F8h..FAh with C7h clock = deleted Data Address Mark
# RETURNS: 0 = OK, get next byte
# -1 = resync (end of Index Mark, end of ID/Data Record, or error)
# ------------------------------------------------------------------------
def process_byteFM(self, val):
if val == 0x1FC: # 00h/FCh Index Mark
self.display_byte(0x00, False)
self.display_byte(0xFC, True)
self.field_start = self.byte_start
self.IM += 1
self.display_field('x')
self.pb_state = 5
return 0
elif val == 0x1FE: # 00h/mFEh ID Address Mark
self.display_byte(0x00, False)
self.iniz_crc()
self.display_byte(0xFE, True)
self.crc(0xFE)
self.field_start = self.byte_start
self.display_field('i')
self.IDlastAM = self.field_start
self.IDcrc = 0
self.pb_state = 1
self.byte_cnt = 4
return 0
elif val >= 0x1F8 and val <= 0x1FB: # 00h/mF8h..mFBh Data Address Mark
self.display_byte(0x00, False)
self.iniz_crc()
self.DRmark = (val & 0x0FF)
self.display_byte(self.DRmark, True)
self.crc(self.DRmark)
self.field_start = self.byte_start
self.display_field('d')
if self.IDlastAM > 0 \
and (self.field_start - self.IDlastAM) > self.max_id_data_gap:
self.IDlastAM = -1
self.DRcrc = 0
self.DRcrcok = False
self.pb_state = 2
self.byte_cnt = self.sector_len
return 0
if self.pb_state == 1: # process ID Record byte
self.display_byte(val, False)
self.crc(val)
self.decode_id_rec(self.byte_cnt, val)
self.byte_cnt -= 1
if self.byte_cnt == 0:
self.IDR += 1
self.display_field('I')
self.byte_cnt = 2
self.pb_state = 3
elif self.pb_state == 2: # process Data Record byte
self.display_byte(val, False)
self.crc(val)
self.DRsec[self.sector_len - self.byte_cnt] = val
self.byte_cnt -= 1
if self.byte_cnt == 0:
self.DR += 1
self.display_field('D')
self.byte_cnt = 2
self.pb_state = 4
elif self.pb_state == 3: # process ID record CRC byte
self.display_byte(val, False)
self.crc(val)
self.IDcrc <<= 8
self.IDcrc += val
self.byte_cnt -= 1
if self.byte_cnt == 0:
if self.crc16_accum == 0:
self.CRC_OK += 1
self.display_field('c')
else:
self.CRC_err += 1
self.display_field('e')
self.IDlastAM = -1
self.pb_state = 5
elif self.pb_state == 4: # process Data record CRC byte
self.display_byte(val, False)
self.crc(val)
self.DRcrc <<= 8
self.DRcrc += val
self.byte_cnt -= 1
if self.byte_cnt == 0:
if self.crc16_accum == 0:
self.DRcrcok = True
self.CRC_OK += 1
self.display_field('c')
else:
self.CRC_err += 1
self.display_field('e')
self.pb_state = 5
elif self.pb_state == 5: # process first gap byte after CRC or Index Mark
self.display_byte(val, False)
return -1 # done, unsync
else:
return -1
return 0
# ------------------------------------------------------------------------
# PURPOSE: Process one byte extracted from MFM pulse stream.
# NOTES:
# - Index/Address Mark prefixes are preceded by a 00h byte.
# - When called with 0x1C2/0x1A1 values, the FIFO must have exactly 33
# entries in it, otherwise it must have exactly 17 entries. On exit the
# FIFO will have exactly 1 entry in it, unless there is an error, in which
# case it will still have 17 entries.
# IN: val 00h..FFh normal byte
# 1C2h 00h + first mC2h prefix byte (no clock between bits 3/4)
# 2C2h subsequent mC2h prefix byte (no clock between bits 3/4)
# 1A1h 00h + first mA1h prefix byte (no clock between bits 4/5)
# 2A1h subsequent mA1h prefix byte (no clock between bits 4/5)
# RETURNS: 0 = OK, get next byte
# -1 = resync (end of Index Mark, end of ID/Data Record, or error)
# ------------------------------------------------------------------------
def process_byteMFM(self, val):
if val == 0x1C2: # first 00h/mC2h prefix
self.display_byte(0x00, False)
self.display_byte(0xC2, True)
self.field_start = self.byte_start
self.pb_state = 1
return 0
elif val == 0x1A1: # first 00h/mA1h prefix
self.display_byte(0x00, False)
self.iniz_crc()
self.display_byte(0xA1, True)
self.crc(0xA1)
self.field_start = self.byte_start
if self.fdd: # dynamic A1h prefix count
self.pb_state = 4
else:
self.pb_state = 6
return 0
if self.pb_state == 1: # second mC2h prefix
if val == 0x2C2:
self.display_byte(0xC2, True)
self.crc(0xC2)
self.pb_state = 2
else:
self.put(self.byte_end - 1, self.byte_end, self.out_ann, [15, ['Err']])
return -1
elif self.pb_state == 2: # third mC2h prefix
if val == 0x2C2:
self.display_byte(0xC2, True)
self.crc(0xC2)
self.pb_state = 3
else:
self.put(self.byte_end - 1, self.byte_end, self.out_ann, [15, ['Err']])
return -1
elif self.pb_state == 3: # FCh Index Mark
if val == 0xFC:
self.display_byte(val, False)
self.crc(val)
self.IM += 1
self.display_field('x')
self.pb_state = 11
else:
self.put(self.byte_end - 1, self.byte_end, self.out_ann, [15, ['Err']])
return -1
elif self.pb_state == 4: # second mA1h prefix
if val == 0x2A1:
self.display_byte(0xA1, True)
self.crc(0xA1)
self.pb_state = 5
else:
self.put(self.byte_end - 1, self.byte_end, self.out_ann, [15, ['Err']])
return -1
elif self.pb_state == 5: # third mA1h prefix
if val == 0x2A1:
self.display_byte(0xA1, True)
self.crc(0xA1)
self.pb_state = 6
else:
self.put(self.byte_end - 1, self.byte_end, self.out_ann, [15, ['Err']])
return -1
elif self.pb_state == 6:
if ((self.header_bytes == 8) and (val == 0xFE)) or ((self.header_bytes == 7) and ((val & 0xFC) == 0xFC)): # FEh ID Address Mark
self.display_byte(val, False)
self.crc(val)
self.block_header_byte = val;
self.display_field('i')
self.IDlastAM = self.field_start
self.IDcrc = 0
self.pb_state = 7
self.byte_cnt = self.header_bytes - 4
elif val >= 0xF8 and val <= 0xFB: # F8h..FBh Data Address Mark
self.display_byte(val, False)
self.crc(val)
self.DRmark = val
self.display_field('d')
if self.IDlastAM > 0 \
and (self.field_start - self.IDlastAM) > self.max_id_data_gap:
self.IDlastAM = -1
self.DRcrc = 0
self.DRcrcok = False
self.pb_state = 8
self.byte_cnt = self.sector_len
else:
self.put(self.byte_end - 1, self.byte_end, self.out_ann, [15, ['Err']])
return -1
elif self.pb_state == 7: # process ID Record byte
self.display_byte(val, False)
self.crc(val)
self.decode_id_rec(self.byte_cnt, val)
self.byte_cnt -= 1
if self.byte_cnt == 0:
self.IDR += 1
self.display_field('I')
self.pb_state = 9
self.byte_cnt = self.header_crc_bytes
elif self.pb_state == 8: # process Data Record byte
self.display_byte(val, False)
self.crc(val)
self.DRsec[self.sector_len - self.byte_cnt] = val
self.byte_cnt -= 1
if self.byte_cnt == 0:
self.DR += 1
self.display_field('D')
self.pb_state = 10
self.byte_cnt = self.data_crc_bytes
elif self.pb_state == 9: # process ID record CRC byte
self.display_byte(val, False)
self.crc(val)
self.IDcrc <<= 8
self.IDcrc += val
self.byte_cnt -= 1
if self.byte_cnt == 0:
if self.crc16_accum == 0:
self.CRC_OK += 1
self.display_field('c')
else:
self.CRC_err += 1
self.display_field('e')
self.IDlastAM = -1
self.pb_state = 11
elif self.pb_state == 10: # process Data record CRC byte
self.display_byte(val, False)
self.crc(val)
self.DRcrc <<= 8
self.DRcrc += val
self.byte_cnt -= 1
if self.byte_cnt == 0:
if self.data_crc_bytes == 2:
if self.crc16_accum == 0:
self.DRcrcok = True
self.CRC_OK += 1
self.display_field('c')
else:
self.CRC_err += 1
self.display_field('e')
elif self.data_crc_bytes == 4:
if self.crc32_accum == 0:
self.DRcrcok = True
self.CRC_OK += 1
self.display_field('c')
else:
self.CRC_err += 1
self.display_field('e')
elif self.data_crc_bytes == 7:
if self.crc56_accum == 0:
self.DRcrcok = True
self.CRC_OK += 1
self.display_field('c')
else:
self.CRC_err += 1
self.display_field('e')
self.pb_state = 11
elif self.pb_state == 11: # process first gap byte after CRC or Index Mark
self.display_byte(val, False)
return -1 # done, unsync
else:
return -1
return 0
# ------------------------------------------------------------------------
# PURPOSE: Write one decoded sector to the binary output file.
# NOTES: The UFDR C program uses a slightly different format for the output
# file -- it writes the cylinder and side numbers from the track table
# after the 0x7777 magic number, whereas the Python program just repeats
# the cylinder and side numbers from the ID Record.
# ------------------------------------------------------------------------
def decode_end(self):
pass
# ------------------------------------------------------------------------
# PURPOSE: Main protocol decoding loop.
# NOTES:
# - It automatically terminates when self.wait() requests termination
# due to end-of-data reached before specified condition found.
# ------------------------------------------------------------------------
def decode(self):
# --- Verify that a sample rate was specified.
if not self.samplerate:
raise SamplerateError('Cannot decode without samplerate.')
# --- Initialize various (half-)bit-cell-window and other variables.
bc10N = self.samplerate / self.data_rate # nominal 1.0 bit cell window size (in fractional samples)
bc05L = (bc10N * 0.5) - (bc10N * 0.25 * 0.80) # lower/upper limits of 0.5 bit cell window size
bc05U = (bc10N * 0.5) + (bc10N * 0.25 * 0.80)
bc10L = (bc10N * 1.0) - (bc10N * 0.25 * 0.80) # lower/upper limits of 1.0 bit cell window size
bc10U = (bc10N * 1.0) + (bc10N * 0.25 * 0.80)
bc15L = (bc10N * 1.5) - (bc10N * 0.25 * 0.80) # lower/upper limits of 1.5 bit cell window size
bc15U = (bc10N * 1.5) + (bc10N * 0.25 * 0.80)
bc20L = (bc10N * 2.0) - (bc10N * 0.25 * 0.80) # lower/upper limits of 2.0 bit cell window size
bc20U = (bc10N * 2.0) + (bc10N * 0.25 * 0.80)
window_size = bc10N / 2.0 # current half-bit-cell window size (in fractional samples)
window_size_filter_accum = window_size * 32.0 # averaging filter accumulator for window size (in fractional samples)
hbcpi = 0.0 # number of half-bit-cell windows per leading edge interval
window_start = 0.0 # start of current half-bit-cell window (fractional sample number)
window_end = window_start + window_size # end of current half-bit-cell window (fractional sample number)
window_adj = 0.0 # adjustment to window_end (in fractional samples)
clock_cell = 'c'
data_cell = 'd'
clock_data = clock_cell # current half-bit-cell window is clock_cell vs. data_cell
v = 0 # 1 = edge in current window, 0 = no edge
shift31 = 0 # 31-bit pattern shift register (of half-bit-cells)
data_byte = 0 # 8-bit data byte shift register (of bit cells)
bit_cnt = 0 # number of bits processed in current byte (0..8)
byte_sync = False # True = bit/byte-sync'd, False = not sync'd
win_sync = False # True = half-bit-cell window sync'd re clock_cell vs. data_cell ?
last_interval = 0 # previous interval (in samples, 1..n)
interval = 0 # current interval (in samples, 1..n)
# --- Process all input data.
while True:
# Wait for leading edge (rising or falling) on channel 0. Also handle
# extra pulses on channel 1, and disable/suppress signal on channel 2.
if self.rising_edge:
(data_pin, extra_pin, suppress_pin) = self.wait([{0: 'r', 2: 'l'}, {1: 'r', 2: 'l'}])
else:
(data_pin, extra_pin, suppress_pin) = self.wait([{0: 'f', 2: 'l'}, {1: 'r', 2: 'l'}])
# Display summary report on last annotation row. Reporting
# sample number must be on or before last leading edge.
# Calculate interval since previous leading edge.
last_interval = interval
if self.last_samplenum is None:
interval = int(bc10N)
else:
interval = self.samplenum - self.last_samplenum
if self.last_samplenum is not None:
interval_nsec = int(((interval * 1000) + (self.samplerateMSps / 2)) / self.samplerateMSps)
self.chunks += 1
self.Intrvls += 1
# Inter-track quiet gap resets ID/Data record matching.
if interval > self.samples30usec:
self.IDlastAM = -1
# If '0010101' pattern detected in 'extra' channel, display summary report.
if interval == 2 and last_interval == 2:
self.err_print("'0010101' pattern detected", self.samplenum)
# Update averaged half-bit-cell window size if interval within tolerance.
# Also display leading-edge to leading-edge annotation, showing starting
# sample number, and interval in nsec.
if self.encodingFM:
if interval >= bc05L and interval <= bc05U:
hbcpi = 1.0
elif interval >= bc10L and interval <= bc10U:
hbcpi = 2.0
else:
self.OoTI += 1
hbcpi = 0.0
else: # MFM
if interval >= bc10L and interval <= bc10U:
hbcpi = 2.0
elif interval >= bc15L and interval <= bc15U:
hbcpi = 3.0
elif interval >= bc20L and interval <= bc20U:
hbcpi = 4.0
else:
self.OoTI += 1
hbcpi = 0.0
if hbcpi > 0.1:
window_size_filter_accum -= (window_size * hbcpi)
window_size_filter_accum += interval
window_size = window_size_filter_accum / 32.0
if self.last_samplenum is not None:
self.put(self.last_samplenum, self.samplenum, self.out_ann,
[13, ['s%d i%dns' % (self.last_samplenum, interval_nsec)]])
else:
if self.last_samplenum is not None:
self.put(self.last_samplenum, self.samplenum, self.out_ann,
[14, ['s%d i%dns OoTI' % (self.last_samplenum, interval_nsec)]])
self.put(self.samplenum - 1, self.samplenum, self.out_ann, [15, ['Err']])
# --- Process half-bit-cell windows until current edge falls inside.
while True:
# Process half-bit-cell window with an edge in it.
if self.samplenum >= window_start and self.samplenum < window_end:
v = 1 # window value is '1'
# Shift position of window to put edge closer to centre.
window_adj = (self.samplenum - ((window_start + window_end) / 2.0)) / 1.75 #//DEBUG - use better algorithm?
if window_adj > (window_size / 4.0): #//DEBUG - use better algorithm?
window_adj = window_size / 4.0
window_end += window_adj
# Edge fell in previous window, discard and resync.
elif self.samplenum < window_start:
self.fifo_wv[self.fifo_wp] += 1 # incr. number of leading edges in window
self.EiPW += 1
byte_sync = False
shift31 = 0
break
# Process window with no edge in it.
else:
v = 0 # window value is '0'
# end if
# Shift current window value into lsb position of pattern shift register.
shift31 = ((shift31 & 0x3FFFFFFF) << 1) + v
# Display all MFM mC2h and mA1h prefix bytes to help with locating damaged records.
win_start = int(round(window_start))
win_end = int(round(window_end))
if (not self.encodingFM) and self.dsply_pfx:
if (shift31 & 0xFFFF) == 0x4489:
self.put(win_start, win_end, self.out_ann, [12, ['A1']])
elif (shift31 & 0xFFFF) == 0x5224:
self.put(win_start, win_end, self.out_ann, [12, ['C2']])
# Store start/end of current window and its value into FIFO.
self.inc_fifo_wp()
self.fifo_ws[self.fifo_wp] = win_start
self.fifo_we[self.fifo_wp] = win_end
self.fifo_wv[self.fifo_wp] = v
# Not sync'd yet, look for sync pattern.
# The FIFO must have exactly 33 entries in it.
if (not byte_sync) and (self.fifo_cnt == 33):
# Process FM patterns.
if self.encodingFM:
# FM ID Address Mark pattern found.
if shift31 == 0x2AAAF57E: # 00h,mFEh bytes
data_byte = 0x1FE
byte_sync = True
win_sync = True
# FM Data Address Mark pattern found.
elif shift31 == 0x2AAAF56F: # 00h,mFBh bytes
data_byte = 0x1FB
byte_sync = True
win_sync = True
elif shift31 == 0x2AAAF56A: # 00h,mF8h bytes
data_byte = 0x1F8
byte_sync = True
win_sync = True
elif shift31 == 0x2AAAF56B: # 00h,mF9h bytes
data_byte = 0x1F9
byte_sync = True
win_sync = True
elif shift31 == 0x2AAAF56E: # 00h,mFAh bytes
data_byte = 0x1FA
byte_sync = True
win_sync = True
# FM Index Mark pattern found.
elif shift31 == 0x2AAAF77A: # 00h,mFCh bytes
data_byte = 0x1FC
byte_sync = True
win_sync = True
# Process MFM patterns.
else:
# MFM ID or Data Address Mark initial pattern found.
if shift31 == 0x2AAA4489: # initial 00h,mA1h prefix bytes
data_byte = 0x1A1
byte_sync = True
win_sync = True
# MFM Index Mark initial pattern found.
elif shift31 == 0x2AAA5224: # initial 00h,mC2h prefix bytes
data_byte = 0x1C2
byte_sync = True
win_sync = True
# Process and display (initial) mark pattern.
if byte_sync:
if self.encodingFM:
self.process_byteFM(data_byte)
else:
self.process_byteMFM(data_byte)
clock_data = data_cell
bit_cnt = 0
# Already sync'd, process next data bit.
elif clock_data == data_cell:
data_byte = ((data_byte & 0x7F) << 1) + v
bit_cnt += 1
# Process and display next complete data byte.
# The FIFO must have exactly 17 entries in it.
if bit_cnt == 8 and self.fifo_cnt == 17:
# Process FM byte.
if self.encodingFM:
if self.process_byteFM(data_byte) == 0:
bit_cnt = 0
else:
shift31 = 0
byte_sync = False
# Process MFM byte.
else:
if (shift31 & 0xFFFF) == 0x4489: # mA1h prefix byte
data_byte = 0x2A1
elif (shift31 & 0xFFFF) == 0x5224: # mC2h prefix byte
data_byte = 0x2C2
if self.process_byteMFM(data_byte) == 0:
bit_cnt = 0
else:
shift31 = 0
byte_sync = False
# Display one half-bit-cell window annotation. (If not sync'd,
# display_bits() won't be called to pull entries from the FIFO,
# but it needs to have 33-1+1 entries for self.process_byteFM/MFM().)
if self.fifo_cnt >= 33:
win_start = self.fifo_ws[self.fifo_rp]
win_end = self.fifo_we[self.fifo_rp]
win_val = self.fifo_wv[self.fifo_rp]
self.inc_fifo_rp()
if win_sync:
if self.dsply_sn:
if win_val > 1:
self.err_print('extra pulse in window', win_start)
self.put(win_start, win_end, self.out_ann,
[0, ['%d d (extra pulse in win) s%d' % (win_val, win_start), '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[3, ['%d d s%d' % (win_val, win_start), '%d' % win_val]])
else:
if win_val > 1:
self.err_print('extra pulse in window', win_start)
self.put(win_start, win_end, self.out_ann,
[0, ['%d d (extra pulse in win)' % win_val, '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[3, ['%d d' % win_val, '%d' % win_val]])
win_sync = False
else:
if self.dsply_sn:
if win_val > 1:
self.err_print('extra pulse in window', win_start)
self.put(win_start, win_end, self.out_ann,
[0, ['%d (extra pulse in win) s%d' % (win_val, win_start), '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[1, ['%d s%d' % (win_val, win_start), '%d' % win_val]])
else:
if win_val > 1:
self.err_print('extra pulse in window', win_start)
self.put(win_start, win_end, self.out_ann,
[0, ['%d (extra pulse in win)' % win_val, '%d' % win_val]])
else:
self.put(win_start, win_end, self.out_ann,
[1, ['%d' % win_val]])
# Toggle clock vs. data state.
if clock_data == data_cell:
clock_data = clock_cell
else:
clock_data = data_cell
# Calculate next half-bit-cell window location.
window_start = window_end
window_end += window_size
# If edge processed in current window, get next edge.
if v == 1: break
#--- end while
# Store data for next round.
self.last_samplenum = self.samplenum
#--- end while