gram/dfii.py

   1 # This file is Copyright (c) 2015 Sebastien Bourdeauducq <sb@m-labs.hk>
   2 # This file is Copyright (c) 2016-2019 Florent Kermarrec <florent@enjoy-digital.fr>
   3 # This file is Copyright (c) 2020 LambdaConcept <contact@lambdaconcept.com>
   4 # License: BSD
   5
   6 from nmigen import *
   7
   8 from gram.phy import dfi
   9 from lambdasoc.periph import Peripheral
  10
  11 # PhaseInjector ------------------------------------------------------------------------------------
  12
  13 class PhaseInjector(Peripheral, Elaboratable):
  14     def __init__(self, phase):
  15         super().__init__(name = "phaseinjector")
  16
  17         bank = self.csr_bank()
  18         self._command = bank.csr(6, "rw")
  19         self._command_issue = bank.csr(1, "rw")
  20         self._address = bank.csr(len(phase.address), "rw")
  21         self._baddress = bank.csr(len(phase.bank), "rw")
  22         self._wrdata = bank.csr(len(phase.wrdata), "rw")
  23         self._rddata = bank.csr(len(phase.rddata), "rw")
  24
  25         self._phase = phase
  26
  27     def elaborate(self, platform):
  28         m = Module()
  29
  30         m.d.comb += [
  31             self._phase.address.eq(self._address.r_data),
  32             self._phase.bank.eq(self._baddress.r_data),
  33             self._phase.wrdata_en.eq(self._command_issue.r_stb & self._command.r_data[4]),
  34             self._phase.rddata_en.eq(self._command_issue.r_stb & self._command.r_data[5]),
  35             self._phase.wrdata.eq(self._wrdata.r_data),
  36             self._phase.wrdata_mask.eq(0)
  37         ]
  38
  39         with m.If(self._command_issue.r_stb):
  40             m.d.comb += [
  41                 self._phase.cs_n.eq(Repl(value=~self._command.r_data[0], count=len(self._phase.cs_n))),
  42                 self._phase.we_n.eq(~self._command.r_data[1]),
  43                 self._phase.cas_n.eq(~self._command.r_data[2]),
  44                 self._phase.ras_n.eq(~self._command.r_data[3]),
  45             ]
  46         with m.Else():
  47             m.d.comb += [
  48                 self._phase.cs_n.eq(Repl(value=1, count=len(self._phase.cs_n))),
  49                 self._phase.we_n.eq(1),
  50                 self._phase.cas_n.eq(1),
  51                 self._phase.ras_n.eq(1),
  52             ]
  53
  54         with m.If(self._phase.rddata_valid):
  55             m.d.sync += self._rddata.w_data.eq(self._phase.rddata)
  56
  57         return m
  58
  59 # DFIInjector --------------------------------------------------------------------------------------
  60
  61 class DFIInjector(Peripheral, Elaboratable):
  62     def __init__(self, addressbits, bankbits, nranks, databits, nphases=1):
  63         super().__init__(name = "dfii")
  64
  65         self._nranks = nranks
  66
  67         self._inti  = dfi.Interface(addressbits, bankbits, nranks, databits, nphases)
  68         self.slave  = dfi.Interface(addressbits, bankbits, nranks, databits, nphases)
  69         self.master = dfi.Interface(addressbits, bankbits, nranks, databits, nphases)
  70
  71         bank = self.csr_bank()
  72         self._control = bank.csr(4, "rw")  # sel, cke, odt, reset_n
  73
  74     def elaborate(self, platform):
  75         m = Module()
  76
  77         for n, phase in enumerate(self._inti.phases):
  78             m.submodules += PhaseInjector(phase)
  79
  80         with m.If(self._control.r_data[0]):
  81             m.d.comb += self.slave.connect(self.master)
  82         with m.Else():
  83             m.d.comb += self._inti.connect(self.master)
  84
  85         for i in range(self._nranks):
  86             m.d.comb += [phase.cke[i].eq(self._control.r_data[1]) for phase in self._inti.phases]
  87             m.d.comb += [phase.odt[i].eq(self._control.r_data[2]) for phase in self._inti.phases if hasattr(phase, "odt")]
  88         m.d.comb += [phase.reset_n.eq(self._control.r_data[3]) for phase in self._inti.phases if hasattr(phase, "reset_n")]
  89
  90         return m