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 gram.compat import CSRPrefixProxy
  10 from lambdasoc.periph import Peripheral
  11
  12 # PhaseInjector ------------------------------------------------------------------------------------
  13
  14
  15 class PhaseInjector(Elaboratable):
  16     def __init__(self, csr_bank, phase):
  17         self._command = csr_bank.csr(6, "rw")
  18         self._command_issue = csr_bank.csr(1, "rw")
  19         self._address = csr_bank.csr(len(phase.address), "rw")
  20         self._baddress = csr_bank.csr(len(phase.bank), "rw")
  21         self._wrdata = csr_bank.csr(len(phase.wrdata), "rw")
  22         self._rddata = csr_bank.csr(len(phase.rddata), "rw")
  23
  24         self._phase = phase
  25
  26     def elaborate(self, platform):
  27         m = Module()
  28
  29         m.d.comb += [
  30             self._phase.address.eq(self._address.r_data),
  31             self._phase.bank.eq(self._baddress.r_data),
  32             self._phase.wrdata_en.eq(
  33                 self._command_issue.r_stb & self._command.r_data[4]),
  34             self._phase.rddata_en.eq(
  35                 self._command_issue.r_stb & self._command.r_data[5]),
  36             self._phase.wrdata.eq(self._wrdata.r_data),
  37             self._phase.wrdata_mask.eq(0)
  38         ]
  39
  40         with m.If(self._command_issue.r_stb):
  41             m.d.comb += [
  42                 self._phase.cs_n.eq(
  43                     Repl(value=~self._command.r_data[0], count=len(self._phase.cs_n))),
  44                 self._phase.we_n.eq(~self._command.r_data[1]),
  45                 self._phase.cas_n.eq(~self._command.r_data[2]),
  46                 self._phase.ras_n.eq(~self._command.r_data[3]),
  47             ]
  48         with m.Else():
  49             m.d.comb += [
  50                 self._phase.cs_n.eq(
  51                     Repl(value=1, count=len(self._phase.cs_n))),
  52                 self._phase.we_n.eq(1),
  53                 self._phase.cas_n.eq(1),
  54                 self._phase.ras_n.eq(1),
  55             ]
  56
  57         with m.If(self._phase.rddata_valid):
  58             m.d.sync += self._rddata.w_data.eq(self._phase.rddata)
  59
  60         return m
  61
  62 # DFIInjector --------------------------------------------------------------------------------------
  63
  64
  65 class DFIInjector(Elaboratable):
  66     def __init__(self, csr_bank, addressbits, bankbits, nranks, databits, nphases=1):
  67         self._nranks = nranks
  68
  69         self._inti = dfi.Interface(
  70             addressbits, bankbits, nranks, databits, nphases)
  71         self.slave = dfi.Interface(
  72             addressbits, bankbits, nranks, databits, nphases)
  73         self.master = dfi.Interface(
  74             addressbits, bankbits, nranks, databits, nphases)
  75
  76         self._control = csr_bank.csr(4, "rw")  # sel, cke, odt, reset_n
  77
  78         self._phases = []
  79         for n, phase in enumerate(self._inti.phases):
  80             self._phases += [PhaseInjector(CSRPrefixProxy(csr_bank,
  81                                                           "p{}".format(n)), phase)]
  82
  83     def elaborate(self, platform):
  84         m = Module()
  85
  86         m.submodules += self._phases
  87
  88         with m.If(self._control.r_data[0]):
  89             m.d.comb += self.slave.connect(self.master)
  90         with m.Else():
  91             m.d.comb += self._inti.connect(self.master)
  92
  93         for i in range(self._nranks):
  94             m.d.comb += [phase.cke[i].eq(self._control.r_data[1])
  95                          for phase in self._inti.phases]
  96             m.d.comb += [phase.odt[i].eq(self._control.r_data[2])
  97                          for phase in self._inti.phases if hasattr(phase, "odt")]
  98         m.d.comb += [phase.reset_n.eq(self._control.r_data[3])
  99                      for phase in self._inti.phases if hasattr(phase, "reset_n")]
 100
 101         return m