litedram/litedram/common.py

168 lines
4.8 KiB
Python

from migen import *
from litex.soc.interconnect import stream
bankbits_max = 3
class PhySettings:
def __init__(self, memtype, dfi_databits,
nphases,
rdphase, wrphase,
rdcmdphase, wrcmdphase,
cl, read_latency, write_latency, nranks=1, cwl=None):
self.memtype = memtype
self.dfi_databits = dfi_databits
self.nranks = nranks
self.nphases = nphases
self.rdphase = rdphase
self.wrphase = wrphase
self.rdcmdphase = rdcmdphase
self.wrcmdphase = wrcmdphase
self.cl = cl
self.read_latency = read_latency
self.write_latency = write_latency
self.cwl = cwl
# Optional DDR3 electrical settings
def add_electrical_settings(self, rtt_nom, rtt_wr, ron):
assert self.memtype == "DDR3"
self.rtt_nom = rtt_nom # Non-Writes on-die termination impedance
self.rtt_wr = rtt_wr # Writes on-die termination impedance
self.ron = ron # Output driver impedance
class GeomSettings:
def __init__(self, bankbits, rowbits, colbits):
self.bankbits = bankbits
self.rowbits = rowbits
self.colbits = colbits
self.addressbits = max(rowbits, colbits)
class TimingSettings:
def __init__(self, tRP, tRCD, tWR, tWTR, tREFI, tRFC, tFAW, tCCD, tRRD):
self.tRP = tRP
self.tRCD = tRCD
self.tWR = tWR
self.tWTR = tWTR
self.tREFI = tREFI
self.tRFC = tRFC
self.tFAW = tFAW
self.tCCD = tCCD
self.tRRD = tRRD
def cmd_layout(address_width):
return [
("valid", 1, DIR_M_TO_S),
("ready", 1, DIR_S_TO_M),
("we", 1, DIR_M_TO_S),
("addr", address_width, DIR_M_TO_S),
("lock", 1, DIR_S_TO_M), # only used internally
("wdata_ready", 1, DIR_S_TO_M),
("rdata_valid", 1, DIR_S_TO_M)
]
def data_layout(data_width):
return [
("wdata", data_width, DIR_M_TO_S),
("wdata_we", data_width//8, DIR_M_TO_S),
("wbank", bankbits_max, DIR_S_TO_M),
("rdata", data_width, DIR_S_TO_M),
("rbank", bankbits_max, DIR_S_TO_M)
]
class LiteDRAMInterface(Record):
def __init__(self, address_align, settings):
rankbits = log2_int(settings.phy.nranks)
self.address_width = settings.geom.rowbits + settings.geom.colbits + rankbits - address_align
self.data_width = settings.phy.dfi_databits*settings.phy.nphases
self.nbanks = settings.phy.nranks*(2**settings.geom.bankbits)
self.nranks = settings.phy.nranks
self.settings = settings
layout = [("bank"+str(i), cmd_layout(self.address_width)) for i in range(self.nbanks)]
layout += data_layout(self.data_width)
Record.__init__(self, layout)
def cmd_description(address_width):
return [
("we", 1),
("addr", address_width)
]
def wdata_description(data_width, with_bank):
r = [
("data", data_width),
("we", data_width//8)
]
if with_bank:
r += [("bank", bankbits_max)]
return r
def rdata_description(data_width, with_bank):
r = [("data", data_width)]
if with_bank:
r += [("bank", bankbits_max)]
return r
class LiteDRAMNativePort:
def __init__(self, mode, address_width, data_width, clock_domain="sys", id=0, with_reordering=False):
self.mode = mode
self.address_width = address_width
self.data_width = data_width
self.clock_domain = clock_domain
self.id = id
self.lock = Signal()
self.with_reordering = with_reordering
self.cmd = stream.Endpoint(cmd_description(address_width))
self.wdata = stream.Endpoint(wdata_description(data_width, with_reordering))
self.rdata = stream.Endpoint(rdata_description(data_width, with_reordering))
if with_reordering:
print("[WARNING] Reordering controller is still experimental")
self.flush = Signal()
# retro-compatibility # FIXME: remove
self.aw = self.address_width
self.dw = self.data_width
self.cd = self.clock_domain
class LiteDRAMNativeWritePort(LiteDRAMNativePort):
def __init__(self, *args, **kwargs):
LiteDRAMNativePort.__init__(self, "write", *args, **kwargs)
class LiteDRAMNativeReadPort(LiteDRAMNativePort):
def __init__(self, *args, **kwargs):
LiteDRAMNativePort.__init__(self, "read", *args, **kwargs)
def cmd_request_layout(a, ba):
return [
("a", a),
("ba", ba),
("cas", 1),
("ras", 1),
("we", 1)
]
def cmd_request_rw_layout(a, ba):
return cmd_request_layout(a, ba) + [
("is_cmd", 1),
("is_read", 1),
("is_write", 1)
]