litedram/litedram/core/bandwidth.py

55 lines
1.7 KiB
Python

# This file is Copyright (c) 2015 Sebastien Bourdeauducq <sb@m-labs.hk>
# This file is Copyright (c) 2016-2019 Florent Kermarrec <florent@enjoy-digital.fr>
# This file is Copyright (c) 2018 John Sully <john@csquare.ca>
# License: BSD
"""LiteDRAM Bandwidth."""
from migen import *
from litex.soc.interconnect.csr import *
class Bandwidth(Module, AutoCSR):
def __init__(self, cmd, data_width, period_bits=24):
self.update = CSR()
self.nreads = CSRStatus(period_bits)
self.nwrites = CSRStatus(period_bits)
self.data_width = CSRStatus(bits_for(data_width), reset=data_width)
# # #
cmd_valid = Signal()
cmd_ready = Signal()
cmd_is_read = Signal()
cmd_is_write = Signal()
self.sync += [
cmd_valid.eq(cmd.valid),
cmd_ready.eq(cmd.ready),
cmd_is_read.eq(cmd.is_read),
cmd_is_write.eq(cmd.is_write)
]
counter = Signal(period_bits)
period = Signal()
nreads = Signal(period_bits)
nwrites = Signal(period_bits)
nreads_r = Signal(period_bits)
nwrites_r = Signal(period_bits)
self.sync += [
Cat(counter, period).eq(counter + 1),
If(period,
nreads_r.eq(nreads),
nwrites_r.eq(nwrites),
nreads.eq(0),
nwrites.eq(0)
).Elif(cmd_valid & cmd_ready,
If(cmd_is_read, nreads.eq(nreads + 1)),
If(cmd_is_write, nwrites.eq(nwrites + 1)),
),
If(self.update.re,
self.nreads.status.eq(nreads_r),
self.nwrites.status.eq(nwrites_r)
)
]