mirror of
https://github.com/gusmanb/logicanalyzer.git
synced 2025-02-05 18:17:44 +00:00
127 lines
4.3 KiB
Python
127 lines
4.3 KiB
Python
##
|
|
## This file is part of the libsigrokdecode project.
|
|
##
|
|
## Copyright (C) 2018 fenugrec <fenugrec@users.sourceforge.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/>.
|
|
##
|
|
|
|
import sigrokdecode as srd
|
|
from common.srdhelper import SrdIntEnum
|
|
|
|
Ann = SrdIntEnum.from_str('Ann', 'ROMDATA')
|
|
Bin = SrdIntEnum.from_str('Bin', 'ROMDATA')
|
|
|
|
class ChannelError(Exception):
|
|
pass
|
|
|
|
class Decoder(srd.Decoder):
|
|
api_version = 3
|
|
id = 'mcs48'
|
|
name = 'MCS-48'
|
|
longname = 'Intel MCS-48'
|
|
desc = 'Intel MCS-48 external memory access protocol.'
|
|
license = 'gplv2+'
|
|
inputs = ['logic']
|
|
outputs = []
|
|
tags = ['Retro computing']
|
|
channels = (
|
|
{'id': 'ale', 'name': 'ALE', 'desc': 'Address latch enable'},
|
|
{'id': 'psen', 'name': '/PSEN', 'desc': 'Program store enable'},
|
|
) + tuple({
|
|
'id': 'd%d' % i,
|
|
'name': 'D%d' % i,
|
|
'desc': 'CPU data line %d' % i
|
|
} for i in range(0, 8)
|
|
) + tuple({
|
|
'id': 'a%d' % i,
|
|
'name': 'A%d' % i,
|
|
'desc': 'CPU address line %d' % i
|
|
} for i in range(8, 12)
|
|
)
|
|
optional_channels = tuple({
|
|
'id': 'a%d' % i,
|
|
'name': 'A%d' % i,
|
|
'desc': 'CPU address line %d' % i
|
|
} for i in range(12, 13)
|
|
)
|
|
annotations = (
|
|
('romdata', 'Address:Data'),
|
|
)
|
|
binary = (
|
|
('romdata', 'AAAA:DD'),
|
|
)
|
|
OFF_ALE, OFF_PSEN = 0, 1
|
|
OFF_DATA_BOT, OFF_DATA_TOP = 2, 10
|
|
OFF_ADDR_BOT, OFF_ADDR_TOP = 10, 14
|
|
OFF_BANK_BOT, OFF_BANK_TOP = 14, 15
|
|
|
|
def __init__(self):
|
|
self.reset()
|
|
|
|
def reset(self):
|
|
self.addr = 0
|
|
self.addr_s = 0
|
|
self.data = 0
|
|
self.data_s = 0
|
|
|
|
# Flag to make sure we get an ALE pulse first.
|
|
self.started = 0
|
|
|
|
def start(self):
|
|
self.out_ann = self.register(srd.OUTPUT_ANN)
|
|
self.out_bin = self.register(srd.OUTPUT_BINARY)
|
|
|
|
def newaddr(self, addr, data):
|
|
# Falling edge on ALE: reconstruct address.
|
|
self.started = 1
|
|
addr = sum([bit << i for i, bit in enumerate(addr)])
|
|
addr <<= len(data)
|
|
addr |= sum([bit << i for i, bit in enumerate(data)])
|
|
self.addr = addr
|
|
self.addr_s = self.samplenum
|
|
|
|
def newdata(self, data):
|
|
# Edge on PSEN: get data.
|
|
data = sum([bit << i for i, bit in enumerate(data)])
|
|
self.data = data
|
|
self.data_s = self.samplenum
|
|
if self.started:
|
|
anntext = '{:04X}:{:02X}'.format(self.addr, self.data)
|
|
self.put(self.addr_s, self.data_s, self.out_ann, [Ann.ROMDATA, [anntext]])
|
|
bindata = self.addr.to_bytes(2, byteorder='big')
|
|
bindata += self.data.to_bytes(1, byteorder='big')
|
|
self.put(self.addr_s, self.data_s, self.out_bin, [Bin.ROMDATA, bindata])
|
|
|
|
def decode(self):
|
|
# Address bits above A11 are optional, and are considered to be A12+.
|
|
# This logic needs more adjustment when more bank address pins are
|
|
# to get supported. For now, having just A12 is considered sufficient.
|
|
has_bank = self.has_channel(self.OFF_BANK_BOT)
|
|
bank_pin_count = 1 if has_bank else 0
|
|
# Sample address on the falling ALE edge.
|
|
# Save data on falling edge of PSEN.
|
|
while True:
|
|
pins = self.wait([{self.OFF_ALE: 'f'}, {self.OFF_PSEN: 'r'}])
|
|
data = pins[self.OFF_DATA_BOT:self.OFF_DATA_TOP]
|
|
addr = pins[self.OFF_ADDR_BOT:self.OFF_ADDR_TOP]
|
|
bank = pins[self.OFF_BANK_BOT:self.OFF_BANK_TOP]
|
|
if has_bank:
|
|
addr += bank[:bank_pin_count]
|
|
# Handle those conditions (one or more) that matched this time.
|
|
if self.matched[0]:
|
|
self.newaddr(addr, data)
|
|
if self.matched[1]:
|
|
self.newdata(data)
|