##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2017 Gerhard Sittig <gerhard.sittig@gmx.net>
##
## 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/>.
##
# This implementation is incomplete. TODO items:
# - Support the optional RESET# pin, detect cold and warm reset.
# - Split slot values into audio samples of their respective width and
# frequency (either on user provided parameters, or from inspection of
# decoded register access).
import sigrokdecode as srd
class ChannelError(Exception):
pass
class Pins:
(SYNC, BIT_CLK, SDATA_OUT, SDATA_IN, RESET) = range(5)
class Ann:
(
BITS_OUT, BITS_IN,
SLOT_OUT_RAW, SLOT_OUT_TAG, SLOT_OUT_ADDR, SLOT_OUT_DATA,
SLOT_OUT_03, SLOT_OUT_04, SLOT_OUT_05, SLOT_OUT_06,
SLOT_OUT_07, SLOT_OUT_08, SLOT_OUT_09, SLOT_OUT_10,
SLOT_OUT_11, SLOT_OUT_IO,
SLOT_IN_RAW, SLOT_IN_TAG, SLOT_IN_ADDR, SLOT_IN_DATA,
SLOT_IN_03, SLOT_IN_04, SLOT_IN_05, SLOT_IN_06,
SLOT_IN_07, SLOT_IN_08, SLOT_IN_09, SLOT_IN_10,
SLOT_IN_11, SLOT_IN_IO,
WARN, ERROR,
) = range(32)
(
BIN_FRAME_OUT,
BIN_FRAME_IN,
BIN_SLOT_RAW_OUT,
BIN_SLOT_RAW_IN,
) = range(4)
class Decoder(srd.Decoder):
api_version = 3
id = 'ac97'
name = "AC '97"
longname = "Audio Codec '97"
desc = 'Audio and modem control for PC systems.'
license = 'gplv2+'
inputs = ['logic']
outputs = ['ac97']
channels = (
{'id': 'sync', 'name': 'SYNC', 'desc': 'Frame synchronization'},
{'id': 'clk', 'name': 'BIT_CLK', 'desc': 'Data bits clock'},
)
optional_channels = (
{'id': 'out', 'name': 'SDATA_OUT', 'desc': 'Data output'},
{'id': 'in', 'name': 'SDATA_IN', 'desc': 'Data input'},
{'id': 'rst', 'name': 'RESET#', 'desc': 'Reset line'},
)
annotations = (
('bit-out', 'Output bits'),
('bit-in', 'Input bits'),
('slot-out-raw', 'Output raw value'),
('slot-out-tag', 'Output TAG'),
('slot-out-cmd-addr', 'Output command address'),
('slot-out-cmd-data', 'Output command data'),
('slot-out-03', 'Output slot 3'),
('slot-out-04', 'Output slot 4'),
('slot-out-05', 'Output slot 5'),
('slot-out-06', 'Output slot 6'),
('slot-out-07', 'Output slot 7'),
('slot-out-08', 'Output slot 8'),
('slot-out-09', 'Output slot 9'),
('slot-out-10', 'Output slot 10'),
('slot-out-11', 'Output slot 11'),
('slot-out-io-ctrl', 'Output I/O control'),
('slot-in-raw', 'Input raw value'),
('slot-in-tag', 'Input TAG'),
('slot-in-sts-addr', 'Input status address'),
('slot-in-sts-data', 'Input status data'),
('slot-in-03', 'Input slot 3'),
('slot-in-04', 'Input slot 4'),
('slot-in-05', 'Input slot 5'),
('slot-in-06', 'Input slot 6'),
('slot-in-07', 'Input slot 7'),
('slot-in-08', 'Input slot 8'),
('slot-in-09', 'Input slot 9'),
('slot-in-10', 'Input slot 10'),
('slot-in-11', 'Input slot 11'),
('slot-in-io-sts', 'Input I/O status'),
# TODO: Add more annotation classes:
# TAG: 'ready', 'valid', 'id', 'rsv'
# CMD ADDR: 'r/w', 'addr', 'unused'
# CMD DATA: 'data', 'unused'
# 3-11: 'data', 'unused', 'double data'
('warning', 'Warning'),
('error', 'Error'),
)
annotation_rows = (
('bits-out', 'Output bits', (Ann.BITS_OUT,)),
('slots-out-raw', 'Output numbers', (Ann.SLOT_OUT_RAW,)),
('slots-out', 'Output slots', (
Ann.SLOT_OUT_TAG, Ann.SLOT_OUT_ADDR, Ann.SLOT_OUT_DATA,
Ann.SLOT_OUT_03, Ann.SLOT_OUT_04, Ann.SLOT_OUT_05, Ann.SLOT_OUT_06,
Ann.SLOT_OUT_07, Ann.SLOT_OUT_08, Ann.SLOT_OUT_09, Ann.SLOT_OUT_10,
Ann.SLOT_OUT_11, Ann.SLOT_OUT_IO,)),
('bits-in', 'Input bits', (Ann.BITS_IN,)),
('slots-in-raw', 'Input numbers', (Ann.SLOT_IN_RAW,)),
('slots-in', 'Input slots', (
Ann.SLOT_IN_TAG, Ann.SLOT_IN_ADDR, Ann.SLOT_IN_DATA,
Ann.SLOT_IN_03, Ann.SLOT_IN_04, Ann.SLOT_IN_05, Ann.SLOT_IN_06,
Ann.SLOT_IN_07, Ann.SLOT_IN_08, Ann.SLOT_IN_09, Ann.SLOT_IN_10,
Ann.SLOT_IN_11, Ann.SLOT_IN_IO,)),
('warnings', 'Warnings', (Ann.WARN,)),
('errors', 'Errors', (Ann.ERROR,)),
)
binary = (
('frame-out', 'Frame bits, output data'),
('frame-in', 'Frame bits, input data'),
('slot-raw-out', 'Raw slot bits, output data'),
('slot-raw-in', 'Raw slot bits, input data'),
# TODO: Which (other) binary classes to implement?
# - Are binary annotations per audio slot useful?
# - Assume 20bit per slot, in 24bit units? Or assume 16bit
# audio samples? Observe register access and derive width
# of the audio data? Dump channels 3-11 or 1-12?
)
def putx(self, ss, es, cls, data):
self.put(ss, es, self.out_ann, [cls, data])
def putf(self, frombit, bitcount, cls, data):
ss = self.frame_ss_list[frombit]
es = self.frame_ss_list[frombit + bitcount]
self.putx(ss, es, cls, data)
def putb(self, frombit, bitcount, cls, data):
ss = self.frame_ss_list[frombit]
es = self.frame_ss_list[frombit + bitcount]
self.put(ss, es, self.out_binary, [cls, data])
def __init__(self):
self.out_binary = None
self.out_ann = None
self.reset()
def reset(self):
self.frame_ss_list = None
self.frame_slot_lens = [0, 16] + [16 + 20 * i for i in range(1, 13)]
self.frame_total_bits = self.frame_slot_lens[-1]
self.handle_slots = {
0: self.handle_slot_00,
1: self.handle_slot_01,
2: self.handle_slot_02,
}
def start(self):
if not self.out_binary:
self.out_binary = self.register(srd.OUTPUT_BINARY)
if not self.out_ann:
self.out_ann = self.register(srd.OUTPUT_ANN)
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
def bits_to_int(self, bits):
# Convert MSB-first bit sequence to integer value.
if not bits:
return 0
count = len(bits)
value = sum([2 ** (count - 1 - i) for i in range(count) if bits[i]])
return value
def bits_to_bin_ann(self, bits):
# Convert MSB-first bit sequence to binary annotation data.
# It's assumed that the number of bits does not (in useful ways)
# fit into an integer, and we need to create an array of bytes
# from the data afterwards, anyway. Hence the separate routine
# and the conversion of eight bits each.
out = []
count = len(bits)
while count > 0:
count -= 8
by, bits = bits[:8], bits[8:]
by = self.bits_to_int(by)
out.append(by)
out = bytes(out)
return out
def int_to_nibble_text(self, value, bitcount):
# Convert number to hex digits for given bit count.
digits = (bitcount + 3) // 4
text = '{{:0{:d}x}}'.format(digits).format(value)
return text
def get_bit_field(self, data, size, off, count):
shift = size - off - count
data >>= shift
mask = (1 << count) - 1
data &= mask
return data
def flush_frame_bits(self):
# Flush raw frame bits to binary annotation.
anncls = Ann.BIN_FRAME_OUT
data = self.frame_bits_out[:]
count = len(data)
data = self.bits_to_bin_ann(data)
self.putb(0, count, anncls, data)
anncls = Ann.BIN_FRAME_IN
data = self.frame_bits_in[:]
count = len(data)
data = self.bits_to_bin_ann(data)
self.putb(0, count, anncls, data)
def start_frame(self, ss):
# Mark the start of a frame.
if self.frame_ss_list:
# Flush bits if we had a frame before the frame which is
# starting here.
self.flush_frame_bits()
self.frame_ss_list = [ss]
self.frame_bits_out = []
self.frame_bits_in = []
self.frame_slot_data_out = []
self.frame_slot_data_in = []
self.have_slots = {True: None, False: None}
def handle_slot_dummy(self, slotidx, bitidx, bitcount, is_out, data):
# Handle slot x, default/fallback handler.
# Only process data of slots 1-12 when slot 0 says "valid".
if not self.have_slots[is_out]:
return
if not self.have_slots[is_out][slotidx]:
return
# Emit a naive annotation with just the data bits that we saw
# for the slot (hex nibbles for density). For audio data this
# can be good enough. Slots with special meaning should not end
# up calling the dummy handler.
text = self.int_to_nibble_text(data, bitcount)
anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG
self.putf(bitidx, bitcount, anncls + slotidx, [text])
# Emit binary output for the data that is contained in slots
# which end up calling the default handler. This transparently
# should translate to "the slots with audio data", as other
# slots which contain management data should have their specific
# handler routines. In the present form, this approach might be
# good enough to get a (header-less) audio stream for typical
# setups where only line-in or line-out are in use.
#
# TODO: Improve this early prototype implementation. For now the
# decoder just exports the upper 16 bits of each audio channel
# that happens to be valid. For an improved implementation, it
# either takes user provided specs or more smarts like observing
# register access (if the capture includes it).
anncls = Ann.BIN_SLOT_RAW_OUT if is_out else Ann.BIN_SLOT_RAW_IN
data_bin = data >> 4
data_bin &= 0xffff
data_bin = data_bin.to_bytes(2, byteorder = 'big')
self.putb(bitidx, bitcount, anncls, data_bin)
def handle_slot_00(self, slotidx, bitidx, bitcount, is_out, data):
# Handle slot 0, TAG.
slotpos = self.frame_slot_lens[slotidx]
fieldoff = 0
anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG
fieldlen = 1
ready = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
text = ['READY: 1', 'READY', 'RDY', 'R'] if ready else ['ready: 0', 'rdy', '-']
self.putf(slotpos + fieldoff, fieldlen, anncls, text)
fieldoff += fieldlen
fieldlen = 12
valid = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
text = ['VALID: {:3x}'.format(valid), '{:3x}'.format(valid)]
self.putf(slotpos + fieldoff, fieldlen, anncls, text)
have_slots = [True] + [False] * 12
for idx in range(12):
have_slots[idx + 1] = bool(valid & (1 << (11 - idx)))
self.have_slots[is_out] = have_slots
fieldoff += fieldlen
fieldlen = 1
rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
if rsv != 0:
text = ['reserved bit error', 'rsv error', 'rsv']
self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text)
fieldoff += fieldlen
# TODO: Will input slot 0 have a Codec ID, or 3 reserved bits?
fieldlen = 2
codec = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
text = ['CODEC: {:1x}'.format(codec), '{:1x}'.format(codec)]
self.putf(slotpos + fieldoff, fieldlen, anncls, text)
fieldoff += fieldlen
def handle_slot_01(self, slotidx, bitidx, bitcount, is_out, data):
# Handle slot 1, command/status address.
slotpos = self.frame_slot_lens[slotidx]
if not self.have_slots[is_out]:
return
if not self.have_slots[is_out][slotidx]:
return
fieldoff = 0
anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG
anncls += slotidx
fieldlen = 1
if is_out:
is_read = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
text = ['READ', 'RD', 'R'] if is_read else ['WRITE', 'WR', 'W']
self.putf(slotpos + fieldoff, fieldlen, anncls, text)
# TODO: Check for the "atomic" constraint? Some operations
# involve address _and_ data, which cannot be spread across
# several frames. Slot 0 and 1 _must_ be provided within the
# same frame (the test should occur in the handler for slot
# 2 of course, in slot 1 we don't know what will follow).
else:
rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
if rsv != 0:
text = ['reserved bit error', 'rsv error', 'rsv']
self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text)
fieldoff += fieldlen
fieldlen = 7
regaddr = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
# TODO: Present 0-63 or 0-126 as the address of the 16bit register?
text = ['ADDR: {:2x}'.format(regaddr), '{:2x}'.format(regaddr)]
self.putf(slotpos + fieldoff, fieldlen, anncls, text)
if regaddr & 0x01:
text = ['odd register address', 'odd reg addr', 'odd addr', 'odd']
self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text)
fieldoff += fieldlen
# Strictly speaking there are 10 data request bits and 2 reserved
# bits for input slots, and 12 reserved bits for output slots. We
# test for 10 and 2 bits, to simplify the logic. Only in case of
# non-zero reserved bits for outputs this will result in "a little
# strange" an annotation. This is a cosmetic issue, we don't mind.
fieldlen = 10
reqdata = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
if is_out and reqdata != 0:
text = ['reserved bit error', 'rsv error', 'rsv']
self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text)
if not is_out:
text = ['REQ: {:3x}'.format(reqdata), '{:3x}'.format(reqdata)]
self.putf(slotpos + fieldoff, fieldlen, anncls, text)
fieldoff += fieldlen
fieldlen = 2
rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
if rsv != 0:
text = ['reserved bit error', 'rsv error', 'rsv']
self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text)
fieldoff += fieldlen
def handle_slot_02(self, slotidx, bitidx, bitcount, is_out, data):
# Handle slot 2, command/status data.
slotpos = self.frame_slot_lens[slotidx]
if not self.have_slots[is_out]:
return
if not self.have_slots[is_out][slotidx]:
return
fieldoff = 0
anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG
anncls += slotidx
fieldlen = 16
rwdata = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
# TODO: Check for zero output data when the operation is a read.
# TODO: Check for the "atomic" constraint.
text = ['DATA: {:4x}'.format(rwdata), '{:4x}'.format(rwdata)]
self.putf(slotpos + fieldoff, fieldlen, anncls, text)
fieldoff += fieldlen
fieldlen = 4
rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen)
if rsv != 0:
text = ['reserved bits error', 'rsv error', 'rsv']
self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text)
fieldoff += fieldlen
# TODO: Implement other slots.
# - 1: cmd/status addr (check status vs command)
# - 2: cmd/status data (check status vs command)
# - 3-11: audio out/in
# - 12: io control/status (modem GPIO(?))
def handle_slot(self, slotidx, data_out, data_in):
# Process a received slot of a frame.
func = self.handle_slots.get(slotidx, self.handle_slot_dummy)
bitidx = self.frame_slot_lens[slotidx]
bitcount = self.frame_slot_lens[slotidx + 1] - bitidx
if data_out is not None:
func(slotidx, bitidx, bitcount, True, data_out)
if data_in is not None:
func(slotidx, bitidx, bitcount, False, data_in)
def handle_bits(self, ss, es, bit_out, bit_in):
# Process a received pair of bits.
# Emit the bits' annotations. Only interpret the data when we
# are in a frame (have seen the start of the frame, and don't
# exceed the expected number of bits in a frame).
if bit_out is not None:
self.putx(ss, es, Ann.BITS_OUT, ['{:d}'.format(bit_out)])
if bit_in is not None:
self.putx(ss, es, Ann.BITS_IN, ['{:d}'.format(bit_in)])
if self.frame_ss_list is None:
return
self.frame_ss_list.append(es)
have_len = len(self.frame_ss_list) - 1
if have_len > self.frame_total_bits:
return
# Accumulate the bits within the frame, until one slot of the
# frame has become available.
slot_idx = 0
if bit_out is not None:
self.frame_bits_out.append(bit_out)
slot_idx = len(self.frame_slot_data_out)
if bit_in is not None:
self.frame_bits_in.append(bit_in)
slot_idx = len(self.frame_slot_data_in)
want_len = self.frame_slot_lens[slot_idx + 1]
if have_len != want_len:
return
prev_len = self.frame_slot_lens[slot_idx]
# Convert bits to integer values. This shall simplify extraction
# of bit fields in multiple other locations.
slot_data_out = None
if bit_out is not None:
slot_bits = self.frame_bits_out[prev_len:]
slot_data = self.bits_to_int(slot_bits)
self.frame_slot_data_out.append(slot_data)
slot_data_out = slot_data
slot_data_in = None
if bit_in is not None:
slot_bits = self.frame_bits_in[prev_len:]
slot_data = self.bits_to_int(slot_bits)
self.frame_slot_data_in.append(slot_data)
slot_data_in = slot_data
# Emit simple annotations for the integer values, until upper
# layer decode stages will be implemented.
slot_len = have_len - prev_len
slot_ss = self.frame_ss_list[prev_len]
slot_es = self.frame_ss_list[have_len]
if slot_data_out is not None:
slot_text = self.int_to_nibble_text(slot_data_out, slot_len)
self.putx(slot_ss, slot_es, Ann.SLOT_OUT_RAW, [slot_text])
if slot_data_in is not None:
slot_text = self.int_to_nibble_text(slot_data_in, slot_len)
self.putx(slot_ss, slot_es, Ann.SLOT_IN_RAW, [slot_text])
self.handle_slot(slot_idx, slot_data_out, slot_data_in)
def decode(self):
have_sdo = self.has_channel(Pins.SDATA_OUT)
have_sdi = self.has_channel(Pins.SDATA_IN)
if not have_sdo and not have_sdi:
raise ChannelError('Either SDATA_OUT or SDATA_IN (or both) are required.')
have_reset = self.has_channel(Pins.RESET)
# Data is sampled at falling CLK edges. Annotations need to span
# the period between rising edges. SYNC rises one cycle _before_
# the start of a frame. Grab the earliest SYNC sample we can get
# and advance to the start of a bit time. Then keep getting the
# samples and the end of all subsequent bit times.
prev_sync = [None, None, None]
pins = self.wait({Pins.BIT_CLK: 'e'})
if pins[Pins.BIT_CLK] == 0:
prev_sync[-1] = pins[Pins.SYNC]
pins = self.wait({Pins.BIT_CLK: 'r'})
bit_ss = self.samplenum
while True:
pins = self.wait({Pins.BIT_CLK: 'f'})
prev_sync.pop(0)
prev_sync.append(pins[Pins.SYNC])
self.wait({Pins.BIT_CLK: 'r'})
if prev_sync[0] == 0 and prev_sync[1] == 1:
self.start_frame(bit_ss)
self.handle_bits(bit_ss, self.samplenum,
pins[Pins.SDATA_OUT] if have_sdo else None,
pins[Pins.SDATA_IN] if have_sdi else None)
bit_ss = self.samplenum