75 lines
2.6 KiB
Python
75 lines
2.6 KiB
Python
# MIT License
|
|
#
|
|
# Copyright (c) 2023 Neil Webber
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
# of this software and associated documentation files (the "Software"), to deal
|
|
# in the Software without restriction, including without limitation the rights
|
|
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
# copies of the Software, and to permit persons to whom the Software is
|
|
# furnished to do so, subject to the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be included in
|
|
# all copies or substantial portions of the Software.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
# SOFTWARE.
|
|
|
|
from interrupts import InterruptManager
|
|
from mmio import MMIO
|
|
|
|
# A convenient reference for addresses:
|
|
# https://gunkies.org/wiki/UNIBUS_Device_Addresses
|
|
|
|
|
|
class UNIBUS:
|
|
def __init__(self, cpu):
|
|
self.cpu = cpu
|
|
self.mmio = MMIO(cpu)
|
|
self.intmgr = InterruptManager()
|
|
self.logger = cpu.logger
|
|
|
|
def resetbus(self):
|
|
self.mmio.resetdevices()
|
|
|
|
|
|
class UNIBUS_1170(UNIBUS):
|
|
UBMAP_OFFS = 0o10200
|
|
UBMAP_N = 62
|
|
|
|
def __init__(self, cpu):
|
|
super().__init__(cpu)
|
|
|
|
# UBAs being 32-bit (well, really 22 bit) values, they
|
|
# are just stored natively that way and broken down
|
|
# into 16-bit components by the mmio function as needed.
|
|
self.ubas = [0] * (self.UBMAP_N // 2)
|
|
self.mmio.register(self.uba_mmio, self.UBMAP_OFFS, self.UBMAP_N)
|
|
|
|
def uba_mmio(self, addr, value=None, /):
|
|
ubanum, hi22 = divmod(addr - self.UBMAP_OFFS, 4)
|
|
uba22 = self.ubas[ubanum]
|
|
|
|
self.logger.debug(f"UBA addr={oct(addr)}, {value=}")
|
|
self.logger.debug(f"{ubanum=}, {hi22=}")
|
|
|
|
if value is None:
|
|
if hi22 == 0:
|
|
return (uba22 >> 16) & 0o077
|
|
else:
|
|
return uba22 & 0o177777
|
|
else:
|
|
# the low bit is enforced to be zero
|
|
if hi22:
|
|
uba22 = ((value & 0o077) << 16) | (uba22 & 0o177776)
|
|
else:
|
|
uba22 = (uba22 & 0o17600000) | (value & 0o177776)
|
|
self.ubas[ubanum] = uba22
|
|
|
|
def busRW(self, ubaddr, value=None):
|
|
pass
|