class Snapshot:
def __init__(self):
self.taken = Signal(reset=0)
self.pre = Registers()
self.post = Registers()
self.addresses_written = Signal(3, reset=0)
self.write_addr = Array([Signal(16) for _ in range(8)])
self.write_data = Array([Signal(8) for _ in range(8)])
self.addresses_read = Signal(3, reset=0)
self.read_addr = Array([Signal(16) for _ in range(8)])
self.read_data = Array([Signal(8) for _ in range(8)])
def read(self, m: Module, addr: Value, data: Value):
with m.If(self.addresses_read != 7):
m.d.sync += self.addresses_read.eq(self.addresses_read + 1)
m.d.sync += self.read_addr[self.addresses_read].eq(addr)
m.d.sync += self.read_data[self.addresses_read].eq(data)
def write(self, m: Module, addr: Value, data: Value):
with m.If(self.addresses_written != 7):
m.d.sync += self.addresses_written.eq(self.addresses_written + 1)
m.d.sync += self.write_addr[self.addresses_written].eq(addr)
m.d.sync += self.write_data[self.addresses_written].eq(data)
def pre_snapshot(self, m: Module, addr: Value, data: Value, reg: Registers):
"""take a synchronous snapshot including addr and data read from ram"""
m.d.sync += [
self.taken.eq(1),
self.pre.eq(reg),
self.read_addr[0].eq(addr),
self.read_data[0].eq(data),
self.addresses_read.eq(1),
self.addresses_written.eq(0),
]
def no_snapshot(self, m: Module):
m.d.sync += self.taken.eq(0)
def post_snapshot(self, m: Module, reg: Registers):
m.d.comb += self.post.eq(reg)
